From 40b41751a4f363a9923dc36ae58be9165db40c1a Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Thu, 9 Apr 2026 14:12:29 +0000
Subject: [PATCH 1/9] updated constitution for more modularity, etc

---
 .specify/memory/constitution.md | 35 ++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/.specify/memory/constitution.md b/.specify/memory/constitution.md
index a1790cd..91ec506 100644
--- a/.specify/memory/constitution.md
+++ b/.specify/memory/constitution.md
@@ -1,16 +1,11 @@
 # Bike Tracking Application Constitution
-<!-- Sync Impact Report v1.12.0
-Rationale: Added explicit modularity and contract-first collaboration governance so teams can deliver independently in parallel while preserving interoperability through stable interfaces and versioned contracts.
+<!-- Sync Impact Report v1.14.0
+Rationale: Strengthened Principle I from "Clean Architecture & DDD" to "Clean Architecture, DDD & Ports-and-Adapters". Added explicit requirements for: port/adapter boundaries, anti-corruption layers for third-party integrations, separation of concerns (no mixed orchestration + I/O methods), modularity (no god services), and abstraction over third-party libraries. Added references to Modern Software Engineering (Dave Farley) and Domain Modeling Made Functional (Scott Wlaschin). Added two new guardrails: mandatory port/adapter boundaries and no god services.
 Modified Sections:
-- Principle IX: Added explicit Modularity, Interfaces & Contract-First Collaboration principle
-- Development Workflow: Added contract-first parallel delivery guidance
-- Definition of Done: Added interface/contract compatibility verification requirement
-- Testing Strategy: Added integration contract-compatibility testing expectation
-- Development Approval Gates: Added contract boundary freeze gate before implementation
-- Compliance Audit Checklist: Added modular boundary and contract compatibility checks
-- Guardrails: Added non-negotiable interface/contract boundary rules for cross-module integration
-Status: Approved — modular architecture and contract-first parallel delivery are now constitutional requirements
-Current Update (v1.13.0): Added Principle X — Trunk-Based Development, Continuous Integration & Delivery. Codified branching strategy (short-lived feature branches, git worktrees, PR-gated merges with validation builds), feature flag governance (max 5 active, mandatory cleanup), and PR completion policy (owner-only completion, GitHub issue linkage required).
+- Principle I: Expanded to include Ports and Adapters, ACLs, separation of concerns, modularity, and third-party abstraction requirements
+- Guardrails: Added port/adapter boundary enforcement and god-service prohibition rules
+Status: Approved — ports-and-adapters architecture, anti-corruption layers, and modularity are now constitutional requirements
+Previous Update (v1.13.0): Added Principle X — Trunk-Based Development, Continuous Integration & Delivery. Codified branching strategy (short-lived feature branches, git worktrees, PR-gated merges with validation builds), feature flag governance (max 5 active, mandatory cleanup), and PR completion policy (owner-only completion, GitHub issue linkage required).
 Previous Update (v1.12.3): Added mandatory per-migration test coverage governance requiring each migration to include a new or updated automated test, enforced by a migration coverage policy test in CI.
 Previous Updates:
 - v1.12.2: Added mandatory spec-completion gate requiring database migrations to be applied and E2E tests to pass before a spec can be marked done.
@@ -51,11 +46,21 @@ For detailed amendment history, see [DECISIONS.md](./DECISIONS.md).
 
 ## Core Principles
 
-### I. Clean Architecture & Domain-Driven Design
+### I. Clean Architecture, Domain-Driven Design & Ports-and-Adapters
 
-Domain logic isolated from infrastructure concerns via layered architecture aligned with Biker Commuter aggregates: Rides, Expenses, Savings Calculations. Infrastructure dependencies (database, HTTP clients, external APIs) must be injectable and independently testable. Use domain models to express business rules explicitly; repositories and services should abstract data access. Repository pattern separates domain models from persistence details.
+Domain logic isolated from infrastructure concerns via **Ports and Adapters (Hexagonal Architecture)** aligned with Biker Commuter aggregates: Rides, Expenses, Savings Calculations. Infrastructure dependencies (database, HTTP clients, external APIs) must be injectable and independently testable. Use domain models to express business rules explicitly; repositories and services should abstract data access. Repository pattern separates domain models from persistence details.
 
-**Rationale**: Testability without mocking infrastructure; business logic remains framework-agnostic and reusable; easier to reason about domain behavior independent of deployment environment.
+**Architectural Boundaries & Abstractions**:
+- **Ports**: Define explicit interfaces (`I*Repository`, `I*Gateway`, `I*Service`) at domain/application layer boundaries. These are the contracts between layers — stable, owned by the inner layer, and technology-agnostic.
+- **Adapters**: Infrastructure implementations (EF Core repositories, HTTP clients, file system access, notification channels) implement port interfaces. Adapters are replaceable without changing business logic.
+- **Anti-Corruption Layers (ACLs)**: When integrating with external systems or third-party libraries, wrap them behind dedicated abstractions that translate external models into domain language. No third-party types (EF entities, HTTP response models, SDK-specific types) may leak into application or domain layers. Reference: *Domain Modeling Made Functional* (Scott Wlaschin) — model boundaries as explicit translation layers.
+- **Separation of Concerns & Cohesion**: Each class/module has a single, well-defined responsibility. Orchestration logic (workflow coordination) is separated from business rules (validation, calculation) and from infrastructure I/O (persistence, notifications, external calls). Functions that mix orchestration, business rules, and I/O in the same method body violate this principle.
+- **Modularity**: Services are small, focused, and composable. Prefer multiple cohesive services over a single "god service" that handles an entire feature's workflow. Break large orchestration methods into named, testable pipeline steps.
+- **Abstraction over third-party libraries**: Never depend directly on concrete third-party types in application/domain code. Wrap `DbContext`, `HttpClient`, `ILogger`, SignalR hubs, and all external SDKs behind owned interfaces so they can be replaced, decorated, or tested in isolation.
+
+**Reference**: *Modern Software Engineering* (Dave Farley) — manage complexity through modularity, separation of concerns, abstraction, and loose coupling. Optimize for learning and managing complexity, not for output.
+
+**Rationale**: Testability without mocking infrastructure; business logic remains framework-agnostic and reusable; easier to reason about domain behavior independent of deployment environment. Port/adapter boundaries make dependencies explicit and replaceable. Anti-corruption layers protect domain integrity when external systems change. Correct cohesion and separation of concerns prevent "god classes" that are hard to test, extend, and reason about.
 
 ### II. Functional Programming (Pure & Impure Sandwich)
 
@@ -555,6 +560,8 @@ Breaking these guarantees causes architectural decay and technical debt accrual:
 - **Expected-flow C# logic uses Result, not exceptions** — validation, not-found, conflict, and authorization business outcomes must be returned via typed Result objects (including error code/message metadata). Throwing exceptions for these expected outcomes is prohibited; exceptions are only for truly unexpected failures.
 - **Cross-module work is contract-first and interface-bound** — teams must integrate through explicit interfaces and versioned contracts only; direct coupling to another module's internal implementation is prohibited.
 - **No Entity Framework DbContext in domain layer** — domain must remain infrastructure-agnostic. If domain needs persistence logic, use repository pattern abstracting EF.
+- **Port/Adapter boundaries are mandatory** — application and domain layers define ports (interfaces); infrastructure provides adapters (implementations). No concrete infrastructure types (`DbContext`, `HttpClient`, third-party SDK classes) referenced directly in application orchestration or domain logic. All I/O goes through owned interfaces. A service that directly calls `dbContext.SaveChangesAsync()` alongside business logic violates this boundary — persistence must be behind a repository or unit-of-work port.
+- **No god services** — a single class must not own the entire workflow of a feature (parsing, validation, persistence, background processing, notifications, cancellation). Break into cohesive collaborators: one for orchestration, one for persistence, one for row processing, etc. If a class has more than ~3 injected dependencies or methods longer than ~30 lines of business logic, it likely violates separation of concerns and should be decomposed.
 - **Secrets management by deployment context** — **Cloud**: all secrets in Azure Key Vault; **Local**: User Secrets or environment variables. No connection strings, API keys, or OAuth secrets in appsettings.json, code, or GitHub. Pre-commit hooks enforce this. **⚠️ This repository is public on GitHub**: any committed secret is immediately and permanently exposed to the internet; treat any accidental secret commit as an immediate security incident requiring credential rotation.
 - **Event schema is append-only** — never mutate existing events. If schema changes needed, create new event type and version old events. Immutability is non-negotiable.
 - **F# domain types must marshal through EF Core value converters** — no raw EF entities exposed to C# API layer. C# records serve as API DTOs; converters handle F#-to-C# translation.

From ccd73d5d2975daa1c23f4343285eb8fa249a59c4 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Thu, 9 Apr 2026 14:13:37 +0000
Subject: [PATCH 2/9] implementation up to US3 e2e tests

---
 .../checklists/requirements.md                |  38 +
 .../contracts/api-contracts.md                | 188 +++++
 specs/013-csv-ride-import/data-model.md       | 124 ++++
 specs/013-csv-ride-import/plan.md             | 198 ++++++
 specs/013-csv-ride-import/quickstart.md       | 193 ++++++
 specs/013-csv-ride-import/research.md         |  96 +++
 specs/013-csv-ride-import/spec.md             | 184 +++++
 specs/013-csv-ride-import/tasks.md            | 289 ++++++++
 .../Application/Imports/CsvParserTests.cs     |  52 ++
 .../DuplicateResolutionServiceTests.cs        |  70 ++
 .../Imports/ImportProgressEstimatorTests.cs   |  60 ++
 .../Endpoints/ImportEndpointsTests.cs         | 428 ++++++++++++
 .../MigrationTestCoveragePolicyTests.cs       |   2 +
 .../Application/Imports/CsvParser.cs          |  88 +++
 .../Imports/CsvRideImportService.cs           | 490 +++++++++++++
 .../Application/Imports/CsvValidationRules.cs | 172 +++++
 .../Imports/DuplicateResolutionService.cs     |  50 ++
 .../Imports/ICsvRideImportService.cs          |  30 +
 .../Imports/IDuplicateResolutionService.cs    |  14 +
 .../Imports/ImportConflictException.cs        |   3 +
 .../Imports/ImportProgressEstimator.cs        |  61 ++
 .../Notifications/ImportProgressNotifier.cs   |  47 ++
 .../Contracts/ImportContracts.cs              |  75 ++
 .../Endpoints/ImportEndpoints.cs              | 175 +++++
 .../Persistence/BikeTrackingDbContext.cs      | 107 +++
 .../Persistence/Entities/ImportJobEntity.cs   |  22 +
 .../Persistence/Entities/ImportRowEntity.cs   |  23 +
 ...0260408185627_AddCsvRideImport.Designer.cs | 647 ++++++++++++++++++
 .../20260408185627_AddCsvRideImport.cs        | 110 +++
 .../BikeTrackingDbContextModelSnapshot.cs     | 187 +++++
 src/BikeTracking.Api/Program.cs               |   6 +
 src/BikeTracking.Frontend/src/App.tsx         |   2 +
 .../DuplicateResolutionDialog.css             |  81 +++
 .../DuplicateResolutionDialog.test.tsx        | 172 +++++
 .../DuplicateResolutionDialog.tsx             | 135 ++++
 .../import-rides/ImportProgressPanel.test.tsx |  52 ++
 .../import-rides/ImportProgressPanel.tsx      |  45 ++
 .../pages/import-rides/ImportRidesPage.css    |  95 +++
 .../import-rides/ImportRidesPage.test.tsx     | 512 ++++++++++++++
 .../pages/import-rides/ImportRidesPage.tsx    | 389 +++++++++++
 .../src/pages/settings/SettingsPage.css       |  15 +
 .../src/pages/settings/SettingsPage.tsx       |   6 +
 .../src/services/import-api.ts                | 202 ++++++
 .../tests/e2e/import-rides.spec.ts            | 116 ++++
 44 files changed, 6051 insertions(+)
 create mode 100644 specs/013-csv-ride-import/checklists/requirements.md
 create mode 100644 specs/013-csv-ride-import/contracts/api-contracts.md
 create mode 100644 specs/013-csv-ride-import/data-model.md
 create mode 100644 specs/013-csv-ride-import/plan.md
 create mode 100644 specs/013-csv-ride-import/quickstart.md
 create mode 100644 specs/013-csv-ride-import/research.md
 create mode 100644 specs/013-csv-ride-import/spec.md
 create mode 100644 specs/013-csv-ride-import/tasks.md
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs
 create mode 100644 src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/CsvParser.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/ICsvRideImportService.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/ImportConflictException.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/ImportProgressEstimator.cs
 create mode 100644 src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
 create mode 100644 src/BikeTracking.Api/Contracts/ImportContracts.cs
 create mode 100644 src/BikeTracking.Api/Endpoints/ImportEndpoints.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportJobEntity.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportRowEntity.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.Designer.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.cs
 create mode 100644 src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.css
 create mode 100644 src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.test.tsx
 create mode 100644 src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.tsx
 create mode 100644 src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
 create mode 100644 src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
 create mode 100644 src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
 create mode 100644 src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
 create mode 100644 src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
 create mode 100644 src/BikeTracking.Frontend/src/services/import-api.ts
 create mode 100644 src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts

diff --git a/specs/013-csv-ride-import/checklists/requirements.md b/specs/013-csv-ride-import/checklists/requirements.md
new file mode 100644
index 0000000..2667914
--- /dev/null
+++ b/specs/013-csv-ride-import/checklists/requirements.md
@@ -0,0 +1,38 @@
+# Specification Quality Checklist: CSV Ride Import
+
+**Purpose**: Validate specification completeness and quality before proceeding to planning
+**Created**: 2026-04-08
+**Feature**: [spec.md](../spec.md)
+
+## Content Quality
+
+- [x] No implementation details (languages, frameworks, APIs)
+- [x] Focused on user value and business needs
+- [x] Written for non-technical stakeholders
+- [x] All mandatory sections completed
+
+## Requirement Completeness
+
+- [x] No [NEEDS CLARIFICATION] markers remain
+- [x] Requirements are testable and unambiguous
+- [x] Success criteria are measurable
+- [x] Success criteria are technology-agnostic (no implementation details)
+- [x] All acceptance scenarios are defined
+- [x] Edge cases are identified
+- [x] Scope is clearly bounded
+- [x] Dependencies and assumptions identified
+
+## Feature Readiness
+
+- [x] All functional requirements have clear acceptance criteria
+- [x] User scenarios cover primary flows
+- [x] Feature meets measurable outcomes defined in Success Criteria
+- [x] No implementation details leak into specification
+
+## Notes
+
+- All items passed initial validation.
+- The spec intentionally avoids naming specific technologies (SignalR, etc.) in requirements — implementation details will be addressed during planning.
+- "Real-time persistent connection" is used instead of naming a specific protocol, keeping the spec technology-agnostic.
+- Enrichment is scoped to cached data only (no new external calls during import), which simplifies the import pipeline and keeps processing time predictable.
+- The "Override All Duplicates" behavior creates new records alongside existing ones (additive), not a merge or replacement — this is documented in Assumptions.
diff --git a/specs/013-csv-ride-import/contracts/api-contracts.md b/specs/013-csv-ride-import/contracts/api-contracts.md
new file mode 100644
index 0000000..3475242
--- /dev/null
+++ b/specs/013-csv-ride-import/contracts/api-contracts.md
@@ -0,0 +1,188 @@
+# API Contracts: CSV Ride Import
+
+**Feature**: 013-csv-ride-import
+**Date**: 2026-04-08
+**Base path**: `/api/imports`
+
+## New Endpoints
+
+### POST `/api/imports/preview`
+
+Uploads and validates CSV, creates `ImportJob` + `ImportRow` records in `awaiting-confirmation` state.
+
+Request: multipart form-data
+- `file`: CSV file (`.csv`, max 5 MB)
+
+Response: `ImportPreviewResponse`
+
+```csharp
+public sealed record ImportPreviewResponse(
+    long JobId,
+    string FileName,
+    int TotalRows,
+    int ValidRows,
+    int InvalidRows,
+    IReadOnlyList<ImportRowErrorView> Errors,
+    IReadOnlyList<ImportDuplicateView> Duplicates,
+    bool CanStartImport
+);
+
+public sealed record ImportRowErrorView(
+    int RowNumber,
+    string Field,
+    string Message
+);
+
+public sealed record ImportDuplicateView(
+    int RowNumber,
+    DateOnly RideDate,
+    decimal Miles,
+    IReadOnlyList<ExistingRideMatchView> ExistingMatches
+);
+
+public sealed record ExistingRideMatchView(
+    long RideId,
+    DateTime RideDateTimeLocal,
+    decimal Miles,
+    int? RideMinutes,
+    decimal? Temperature,
+    string? Tags,
+    string? Notes
+);
+```
+
+Errors:
+- `400` invalid/missing file, bad CSV schema, file too large
+- `401` unauthenticated
+
+### POST `/api/imports/{jobId}/start`
+
+Starts processing of a previewed import job.
+
+```csharp
+public sealed record StartImportRequest(
+    bool OverrideAllDuplicates,
+    IReadOnlyList<DuplicateResolutionChoice> DuplicateChoices
+);
+
+public sealed record DuplicateResolutionChoice(
+    int RowNumber,
+    string Resolution // "keep-existing" | "replace-with-import"
+);
+
+public sealed record StartImportResponse(
+    long JobId,
+    string Status,
+    int TotalRows
+);
+```
+
+Rules:
+- Requires job ownership by authenticated rider
+- If `OverrideAllDuplicates=true`, per-row duplicate choices are optional
+- Rejects start when job is already processing/completed/cancelled
+
+### GET `/api/imports/{jobId}/status`
+
+Returns current persisted state for reconnect and polling fallback.
+
+```csharp
+public sealed record ImportStatusResponse(
+    long JobId,
+    string Status,
+    int TotalRows,
+    int ProcessedRows,
+    int ImportedRows,
+    int SkippedRows,
+    int FailedRows,
+    int? ProgressPercent,
+    int? EtaRoundedMinutes,
+    ImportCompletionSummary? Summary
+);
+
+public sealed record ImportCompletionSummary(
+    int TotalRows,
+    int ImportedRows,
+    int SkippedRows,
+    int FailedRows,
+    int GasEnrichedRows,
+    int WeatherEnrichedRows,
+    bool Cancelled
+);
+```
+
+### POST `/api/imports/{jobId}/cancel`
+
+Requests cooperative cancellation for an in-progress import.
+
+```csharp
+public sealed record CancelImportResponse(
+    long JobId,
+    string Status,
+    string Message
+);
+```
+
+Rules:
+- Cancellation keeps already-imported rows
+- Idempotent if already cancelled/completed
+
+## Real-time Progress Contract
+
+Progress notifications are emitted for 25% milestones.
+
+```csharp
+public sealed record ImportProgressNotification(
+    long JobId,
+    int ProgressPercent, // 25, 50, 75, 100
+    int ProcessedRows,
+    int TotalRows,
+    int? EtaRoundedMinutes,
+    string Status
+);
+```
+
+## Validation and behavior rules
+
+- Required CSV columns: `Date`, `Miles` (case-insensitive)
+- Optional CSV columns: `Time`, `Temp`, `Tags`, `Notes`
+- Duplicate key: `Date + Miles`
+- Enrichment rules:
+  - Cache-first gas/weather lookup
+  - On cache miss, perform external lookup
+  - Retry once on external failure
+  - If retry fails, skip enrichment field and continue row processing
+  - External lookup throttle: max 4 calls/second
+
+## Frontend TypeScript contract sketch
+
+```typescript
+export interface ImportPreviewResponse {
+  jobId: number;
+  fileName: string;
+  totalRows: number;
+  validRows: number;
+  invalidRows: number;
+  errors: ImportRowErrorView[];
+  duplicates: ImportDuplicateView[];
+  canStartImport: boolean;
+}
+
+export interface ImportStatusResponse {
+  jobId: number;
+  status: "pending" | "validating" | "awaiting-confirmation" | "processing" | "completed" | "cancelled" | "failed";
+  totalRows: number;
+  processedRows: number;
+  importedRows: number;
+  skippedRows: number;
+  failedRows: number;
+  progressPercent?: number;
+  etaRoundedMinutes?: number;
+  summary?: ImportCompletionSummary;
+}
+```
+
+## Backward compatibility
+
+- Existing ride create/edit/history contracts remain unchanged.
+- Import is additive through new endpoints and new frontend route.
diff --git a/specs/013-csv-ride-import/data-model.md b/specs/013-csv-ride-import/data-model.md
new file mode 100644
index 0000000..34b9a5a
--- /dev/null
+++ b/specs/013-csv-ride-import/data-model.md
@@ -0,0 +1,124 @@
+# Data Model: CSV Ride Import
+
+**Feature**: 013-csv-ride-import
+**Date**: 2026-04-08
+**Status**: Complete
+
+## Overview
+
+This feature introduces a persisted import workflow with two new entities plus additive ride-import mapping rules.
+
+1. `ImportJob` tracks one CSV import lifecycle for a rider.
+2. `ImportRow` tracks parsed row state, validation, duplicate metadata, and resolution.
+3. Existing ride entities/events are reused for final persisted rides.
+
+## Entity: ImportJob
+
+Represents one uploaded CSV import request.
+
+| Field | Type | Rules / Notes |
+|------|------|----------------|
+| `Id` | `long` | Primary key |
+| `RiderId` | `long` | Required; rider-scoped ownership |
+| `FileName` | `string` | Required; stored for traceability |
+| `TotalRows` | `int` | `>= 0` |
+| `ProcessedRows` | `int` | `0..TotalRows` |
+| `ImportedRows` | `int` | `>= 0` |
+| `SkippedRows` | `int` | `>= 0` |
+| `FailedRows` | `int` | `>= 0` |
+| `Status` | `string enum` | `pending`, `validating`, `awaiting-confirmation`, `processing`, `completed`, `cancelled`, `failed` |
+| `OverrideAllDuplicates` | `bool` | Default `false` |
+| `EtaMinutesRounded` | `int?` | Rounded to 5-minute increments when available |
+| `CreatedAtUtc` | `DateTime` | Required |
+| `StartedAtUtc` | `DateTime?` | Set when processing begins |
+| `CompletedAtUtc` | `DateTime?` | Set on completed/cancelled/failed |
+| `LastError` | `string?` | Failure summary, if any |
+
+### Validation invariants
+
+- `ProcessedRows <= TotalRows`
+- `ImportedRows + SkippedRows + FailedRows <= ProcessedRows`
+- `Status=completed|cancelled|failed` requires `CompletedAtUtc`
+
+## Entity: ImportRow
+
+Represents one parsed CSV row and its processing state.
+
+| Field | Type | Rules / Notes |
+|------|------|----------------|
+| `Id` | `long` | Primary key |
+| `ImportJobId` | `long` | FK to `ImportJob` |
+| `RowNumber` | `int` | 1-based CSV row index (excluding header) |
+| `RideDateLocal` | `DateOnly?` | Required for valid rows |
+| `Miles` | `decimal?` | Required for valid rows; `(0,200]` |
+| `RideMinutes` | `int?` | Optional; positive when present |
+| `Temperature` | `decimal?` | Optional |
+| `TagsRaw` | `string?` | Optional raw string from CSV |
+| `Notes` | `string?` | Optional |
+| `ValidationStatus` | `string enum` | `valid`, `invalid` |
+| `ValidationErrorsJson` | `string?` | Structured error payload |
+| `DuplicateStatus` | `string enum` | `none`, `duplicate`, `resolved` |
+| `DuplicateResolution` | `string enum?` | `keep-existing`, `replace-with-import`, `override-all` |
+| `ProcessingStatus` | `string enum` | `pending`, `processed`, `skipped`, `failed` |
+| `ExistingRideIdsJson` | `string?` | Existing ride IDs for duplicate dialog context |
+| `CreatedRideId` | `long?` | Created/updated ride ID when processed |
+
+### Validation invariants
+
+- `ValidationStatus=invalid` implies `ValidationErrorsJson` not null
+- `DuplicateStatus=duplicate` implies one or more existing ride references
+- `ProcessingStatus=processed` implies `ValidationStatus=valid`
+
+## Derived model: DuplicateKey
+
+Duplicate detection key per incoming row.
+
+| Component | Source |
+|----------|--------|
+| `Date` | `ImportRow.RideDateLocal` |
+| `Miles` | `ImportRow.Miles` |
+
+A row is duplicate when an existing rider ride matches both date and miles.
+
+## Derived model: ImportProgressSnapshot
+
+Computed status pushed to client at milestones.
+
+| Field | Type | Notes |
+|------|------|-------|
+| `JobId` | `long` | Correlates updates |
+| `Percent` | `int` | Emitted at 25/50/75/100 |
+| `ProcessedRows` | `int` | Current processed count |
+| `TotalRows` | `int` | Denominator |
+| `EtaRoundedMinutes` | `int?` | Rounded to nearest 5 minutes |
+| `Status` | `string` | Current job status |
+
+## Relationship map
+
+- One rider has many `ImportJob` records.
+- One `ImportJob` has many `ImportRow` records.
+- One `ImportRow` may create or update one ride through existing ride services.
+
+## State transitions
+
+### ImportJob state flow
+
+`pending -> validating -> awaiting-confirmation -> processing -> completed`
+
+Alternative terminal paths:
+- `processing -> cancelled`
+- `processing -> failed`
+- `validating -> failed` (fatal parse/infrastructure errors)
+
+### ImportRow state flow
+
+`pending -> (invalid -> failed)`
+`pending -> (valid + non-duplicate -> processed)`
+`pending -> (valid + duplicate -> resolved -> processed|skipped)`
+
+### Cancellation behavior
+
+- Cancellation request marks job cancellation intent.
+- Worker stops after current row boundary.
+- Already processed rows remain persisted.
+- Job ends in `cancelled` with partial summary.
diff --git a/specs/013-csv-ride-import/plan.md b/specs/013-csv-ride-import/plan.md
new file mode 100644
index 0000000..202bfd9
--- /dev/null
+++ b/specs/013-csv-ride-import/plan.md
@@ -0,0 +1,198 @@
+# Implementation Plan: CSV Ride Import
+
+**Branch**: `013-csv-ride-import` | **Date**: 2026-04-08 | **Spec**: [spec.md](./spec.md)
+**Input**: Feature specification from `/specs/013-csv-ride-import/spec.md`
+
+## Summary
+
+Add a new rider-facing CSV import workflow linked from Settings. Riders upload a CSV containing
+Date, Miles, Time, Temp, Tags, and Notes, preview validation results, resolve duplicates, and run
+a long-running server-side import job with 25% progress updates and 5-minute rounded ETA. Import
+enrichment follows a cache-first strategy for gas price and weather, then external lookup on cache
+miss with retry-once-on-failure behavior and 4 calls/second throttling.
+
+## Technical Context
+
+**Language/Version**: C# .NET 10 (API), F# .NET 10 (domain unchanged), TypeScript 6 + React 19 (frontend)
+**Primary Dependencies**: .NET 10 Minimal API, EF Core + SQLite, Aspire orchestration, React 19 + Vite, react-router-dom, existing gas/weather application services, existing realtime notification stack
+**Storage**: SQLite local database via EF Core; additive import-job and import-row persistence; existing ride/event/outbox persistence
+**Testing**: xUnit (backend unit/integration), Vitest (frontend unit), Playwright (E2E)
+**Target Platform**: Local-first web app in DevContainer on Linux/macOS/Windows hosts
+**Project Type**: Aspire-orchestrated web app (React frontend + Minimal API backend)
+**Performance Goals**: Import progress visible within 2 seconds of confirmation; progress events at 25/50/75/100%; 100-row import completes within 5 minutes in normal local conditions
+**Constraints**: Preserve existing event-sourced ride model; no breaking API contract changes; enrich from cache first; external lookup throttle 4 calls/sec; retry once then skip enrichment field; duplicate detection keyed by date+miles; cancellation keeps already imported rows
+**Scale/Scope**: Single-rider local deployment; expected imports in tens to low thousands of rows; one new import page, one import job backend slice, additive contracts and persistence
+
+## Constitution Check
+
+*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*
+
+| Gate | Status | Notes |
+|------|--------|-------|
+| Clean Architecture / DDD | PASS | Import orchestration in application service; parsing/validation/enrichment isolated from endpoints/UI |
+| Functional Core / Side Effects | PASS | Row normalization, duplicate detection keys, ETA calculation are pure helpers; file I/O and API calls remain at edges |
+| Event Sourcing & CQRS | PASS | Imported rides still persisted as ride events + read models through existing write path |
+| Quality-First / TDD | PASS | Quickstart defines explicit red tests for parser, duplicate flow, progress signaling, enrichment fallback |
+| UX Consistency & Accessibility | PASS | New Settings-linked page keeps existing React/CSS patterns and accessible dialogs/status messaging |
+| Performance & Observability | PASS | Long-running job includes progress telemetry, retry policy, throttling, and status query surface |
+| Data Validation & Integrity | PASS | CSV schema + row validation mirrors existing ride validation; duplicate resolution explicit before writes |
+| Experimentation / Security | PASS | Small vertical slice behind authenticated route; external API calls remain server-side only |
+| Modularity / Contract-First | PASS | API/import contracts documented first in contracts artifact before implementation |
+| TDD mandatory gate | PASS | Plan requires user confirmation on failing tests before code implementation |
+| Migration test coverage policy | PASS | New persistence objects/migration must include migration policy test update |
+| Spec completion gate | PASS | Completion requires migration apply + backend tests + frontend lint/build/unit + E2E |
+
+**Constitution Check post-design**: PASS. Phase 1 design keeps additive schemas, contract-first boundaries, and test-first workflow with no constitutional violations.
+
+## Project Structure
+
+### Documentation (this feature)
+
+```text
+specs/013-csv-ride-import/
+├── plan.md
+├── research.md
+├── data-model.md
+├── quickstart.md
+├── contracts/
+│   └── api-contracts.md
+└── tasks.md
+```
+
+### Source Code Layout
+
+```text
+src/BikeTracking.Api/
+├── Application/
+│   ├── Imports/
+│   │   ├── CsvRideImportService.cs                 ← NEW
+│   │   ├── CsvParser.cs                            ← NEW
+│   │   ├── DuplicateResolutionService.cs           ← NEW
+│   │   └── ImportProgressEstimator.cs              ← NEW
+│   ├── Rides/
+│   │   ├── RecordRideService.cs                    ← reuse for imported rows
+│   │   └── EditRideService.cs                      ← optional replacement path when user selects replace
+│   └── Notifications/
+│       └── ImportProgressNotifier.cs               ← NEW (25% milestones)
+├── Contracts/
+│   ├── ImportContracts.cs                          ← NEW
+│   └── RidesContracts.cs                           ← may extend summary payload references
+├── Endpoints/
+│   ├── ImportEndpoints.cs                          ← NEW
+│   └── SettingsEndpoints.cs                        ← extend navigation metadata if needed
+└── Infrastructure/
+    └── Persistence/
+        ├── Entities/
+        │   ├── ImportJobEntity.cs                  ← NEW
+        │   └── ImportRowEntity.cs                  ← NEW
+        ├── BikeTrackingDbContext.cs                ← NEW mappings
+        └── Migrations/
+            └── {timestamp}_AddCsvRideImport.cs     ← NEW
+
+src/BikeTracking.Api.Tests/
+├── Application/
+│   ├── Imports/
+│   │   ├── CsvParserTests.cs                       ← NEW
+│   │   ├── CsvRideImportServiceTests.cs            ← NEW
+│   │   ├── DuplicateResolutionServiceTests.cs      ← NEW
+│   │   └── ImportProgressEstimatorTests.cs         ← NEW
+│   └── Rides/
+│       └── RecordRideServiceTests.cs               ← extend imported-row integration coverage
+├── Endpoints/
+│   └── ImportEndpointsTests.cs                     ← NEW
+└── Infrastructure/
+    └── MigrationTestCoveragePolicyTests.cs         ← extend with migration entry
+
+src/BikeTracking.Frontend/src/
+├── pages/
+│   ├── settings/
+│   │   ├── SettingsPage.tsx                        ← add Import Rides entry
+│   │   └── SettingsPage.test.tsx                   ← extend
+│   └── import-rides/
+│       ├── ImportRidesPage.tsx                     ← NEW
+│       ├── ImportRidesPage.css                     ← NEW
+│       └── ImportRidesPage.test.tsx                ← NEW
+├── components/
+│   └── import-rides/
+│       ├── DuplicateResolutionDialog.tsx           ← NEW
+│       └── ImportProgressPanel.tsx                 ← NEW
+├── services/
+│   ├── import-api.ts                               ← NEW
+│   └── import-api.test.ts                          ← NEW
+└── App.tsx                                         ← route wiring
+```
+
+**Structure Decision**: Existing web app split retained. Backend artifacts stay in
+`src/BikeTracking.Api` and `src/BikeTracking.Api.Tests`; frontend artifacts stay in
+`src/BikeTracking.Frontend/src`. No new projects added.
+
+## Implementation Phases
+
+### Phase 0 - Research
+
+Resolved in `research.md`:
+- CSV parsing strategy and header normalization
+- Duplicate key policy (date+miles) and override behavior
+- Progress signaling milestones and ETA rounding algorithm
+- Cache-first enrichment with external lookup fallback and retry/throttle rules
+- Cancellation semantics and partial completion guarantees
+
+### Phase 1 - Design and Contracts
+
+**Slice 1.1 - Contracts first**
+- Define request/response contracts for upload, preview, duplicate resolution, job start, status,
+  cancellation, and completion summary
+- Define frontend DTOs matching backend contracts
+
+**Slice 1.2 - Data model and persistence**
+- Add import job + import row entities and states
+- Add migration and migration coverage policy update
+
+**Slice 1.3 - Import orchestration**
+- Implement parser/validator pipeline
+- Implement duplicate resolution + override flow
+- Integrate ride creation through existing write services
+
+**Slice 1.4 - Enrichment integration**
+- Cache-first gas/weather lookup
+- External lookup on cache miss
+- Retry once then skip enrichment field
+- Apply shared throttling (4 calls/sec)
+
+**Slice 1.5 - Progress + cancellation**
+- Compute milestone thresholds and emit 25/50/75/100 updates
+- Persist job status and ETA snapshots
+- Support cancel-in-progress while keeping imported rows
+
+### Phase 2 - Frontend UX slice
+
+**Slice 2.1 - Navigation + upload**
+- Add Settings link and import route
+- Upload file, parse preview, show validation errors
+
+**Slice 2.2 - Duplicate workflow**
+- Show duplicate dialog with existing vs incoming details
+- Keep existing / replace / override-all options
+
+**Slice 2.3 - Long-running feedback**
+- Progress panel with milestone updates
+- ETA in 5-minute increments
+- Completion and cancellation summaries
+
+## Test Plan Summary
+
+| Category | Count | Location |
+|----------|-------|----------|
+| Backend unit - CSV parsing/validation | 8 | `Application/Imports/CsvParserTests.cs` |
+| Backend unit - duplicate detection/resolution | 6 | `Application/Imports/DuplicateResolutionServiceTests.cs` |
+| Backend unit - enrichment fallback/retry/throttle | 7 | `Application/Imports/CsvRideImportServiceTests.cs` |
+| Backend unit - progress + ETA | 5 | `Application/Imports/ImportProgressEstimatorTests.cs` |
+| Endpoint/integration - import lifecycle | 7 | `Endpoints/ImportEndpointsTests.cs` |
+| Persistence/migration coverage | 3 | `Infrastructure/MigrationTestCoveragePolicyTests.cs` + persistence tests |
+| Frontend unit | 8 | import page/dialog/progress panel + API service tests |
+| E2E | 5 | upload/preview, duplicate resolution, override-all, long-run progress, cancellation |
+| **Total** | **49** | |
+
+## Complexity Tracking
+
+No constitution violations requiring exception.
diff --git a/specs/013-csv-ride-import/quickstart.md b/specs/013-csv-ride-import/quickstart.md
new file mode 100644
index 0000000..d5e8ef6
--- /dev/null
+++ b/specs/013-csv-ride-import/quickstart.md
@@ -0,0 +1,193 @@
+# Developer Quickstart: CSV Ride Import
+
+**Feature**: 013-csv-ride-import
+**Branch**: `013-csv-ride-import`
+**Date**: 2026-04-08
+
+## Overview
+
+This feature adds a Settings-linked CSV import page that supports preview validation, duplicate
+resolution, long-running processing with milestone progress, cache-first enrichment with external
+fallback, and cooperative cancellation.
+
+## Prerequisites
+
+- DevContainer running
+- App launch: `dotnet run --project src/BikeTracking.AppHost`
+- Existing login and ride flows available
+- Follow strict TDD gate: failing tests first, run red, user confirms failures before implementation
+
+## Implementation order
+
+### Step 1: Define contracts first
+
+Create backend contracts and endpoint signatures before service code.
+
+```text
+src/BikeTracking.Api/Contracts/
+  ImportContracts.cs
+src/BikeTracking.Api/Endpoints/
+  ImportEndpoints.cs
+```
+
+Lock request/response models for:
+- preview upload
+- duplicate resolution/start
+- status query
+- cancellation
+- completion summary
+- progress notification payload
+
+### Step 2: Persistence and migration
+
+Add import job/row entities and EF mappings.
+
+```text
+src/BikeTracking.Api/Infrastructure/Persistence/Entities/
+  ImportJobEntity.cs
+  ImportRowEntity.cs
+src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
+src/BikeTracking.Api/Infrastructure/Persistence/Migrations/
+  {timestamp}_AddCsvRideImport.cs
+```
+
+Update migration policy test.
+
+### Step 3: Parser and validation pipeline
+
+Build CSV parse/normalize/validate helpers.
+
+```text
+src/BikeTracking.Api/Application/Imports/
+  CsvParser.cs
+  CsvValidationRules.cs
+```
+
+Rules to enforce:
+- required columns `Date` + `Miles`
+- case-insensitive headers
+- date parsing per spec assumptions
+- miles range `(0,200]`
+- optional positive time when present
+
+### Step 4: Duplicate workflow
+
+Implement duplicate detection and resolution orchestration.
+
+```text
+src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
+```
+
+Key behavior:
+- duplicate key = date + miles
+- per-row resolution (`keep-existing` or `replace-with-import`)
+- optional override-all bypass
+
+### Step 5: Import orchestration and enrichment
+
+Implement long-running processor.
+
+```text
+src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
+```
+
+Behavior:
+- process valid rows
+- create/update rides via existing ride services
+- cache-first enrichment for gas/weather
+- external lookup on cache miss
+- retry once then skip enrichment field
+- throttle external lookups to 4 calls/sec
+
+### Step 6: Progress, ETA, cancellation
+
+Implement milestone notifier and ETA estimator.
+
+```text
+src/BikeTracking.Api/Application/Imports/
+  ImportProgressEstimator.cs
+src/BikeTracking.Api/Application/Notifications/
+  ImportProgressNotifier.cs
+```
+
+Behavior:
+- notify at 25/50/75/100
+- ETA shown in 5-minute increments when stable
+- cancellation stops remaining rows, keeps imported rows
+
+### Step 7: Frontend route and UX
+
+```text
+src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx
+src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
+src/BikeTracking.Frontend/src/components/import-rides/
+  DuplicateResolutionDialog.tsx
+  ImportProgressPanel.tsx
+src/BikeTracking.Frontend/src/services/import-api.ts
+src/BikeTracking.Frontend/src/App.tsx
+```
+
+UX expectations:
+- upload + preview
+- row-level validation display
+- duplicate resolution dialog with override-all
+- progress + ETA + completion/cancellation summaries
+
+## TDD-first test checklist
+
+Write and run these failing tests first.
+
+### Backend unit
+
+- CSV parser accepts case-insensitive headers
+- Parser rejects missing required columns
+- Row validation reports field-level errors and allows valid rows
+- Duplicate detector flags date+miles matches only
+- Override-all bypasses duplicate prompts
+- Enrichment uses cache first
+- Enrichment calls external on cache miss
+- Enrichment retries once then skips field on second failure
+- Throttle enforces max 4 external calls/second
+- ETA rounds to 5-minute increments after stable sample
+- Cancellation keeps imported rows and stops further processing
+
+### Backend integration / endpoint
+
+- Preview endpoint persists job and row states
+- Start endpoint enforces ownership and valid status transitions
+- Status endpoint returns reconnect-safe state
+- Cancel endpoint transitions job correctly and is idempotent
+- Completion summary counts imported/skipped/failed rows correctly
+
+### Frontend unit
+
+- Settings page shows Import Rides navigation
+- Import page renders preview errors and valid row counts
+- Duplicate dialog displays existing vs incoming row details
+- Override-all toggle alters start payload
+- Progress panel updates milestone percentages and ETA text
+- Cancel action requests cancellation and renders partial summary
+
+### E2E
+
+- Upload -> preview -> start -> completion happy path
+- Duplicate conflict path with keep-existing
+- Duplicate conflict path with override-all
+- Long-running progress milestone updates visible
+- Cancellation mid-import results in partial completion summary
+
+## Verification commands
+
+Run after each meaningful slice:
+
+```bash
+dotnet test BikeTracking.slnx
+cd src/BikeTracking.Frontend && npm run lint && npm run build && npm run test:unit
+cd src/BikeTracking.Frontend && npm run test:e2e
+```
+
+Formatting before merge:
+
+```bash
+csharpier format .
+```
diff --git a/specs/013-csv-ride-import/research.md b/specs/013-csv-ride-import/research.md
new file mode 100644
index 0000000..49bbea5
--- /dev/null
+++ b/specs/013-csv-ride-import/research.md
@@ -0,0 +1,96 @@
+# Research: CSV Ride Import
+
+**Feature**: 013-csv-ride-import
+**Date**: 2026-04-08
+**Status**: Complete
+
+## Decision 1: Import processing model
+
+**Decision**: Use a persisted server-side import job with explicit states (`pending`, `validating`, `awaiting-confirmation`, `processing`, `completed`, `cancelled`, `failed`) instead of a single request/response import endpoint.
+
+**Rationale**:
+- The spec requires long-running processing, milestone progress updates, reconnect-safe status, and cancellation.
+- Persisted job state survives page refresh/navigation and supports status rehydration.
+- This model aligns with local-first reliability and avoids request timeout issues.
+
+**Alternatives considered**:
+- Single blocking POST import endpoint: rejected due to timeout risk and poor UX for long-running jobs.
+- Fire-and-forget import with no persisted status: rejected because users need reliable progress and completion/cancellation summaries.
+
+## Decision 2: CSV schema and validation strategy
+
+**Decision**: Parse headers case-insensitively and require `Date` and `Miles`; treat `Time`, `Temp`, `Tags`, and `Notes` as optional. Validate each row independently and allow valid rows to proceed while reporting invalid rows.
+
+**Rationale**:
+- Matches existing ride validation expectations and spec acceptance scenarios.
+- Independent row validation prevents one bad row from blocking the entire import.
+- Maintains user trust by showing specific field-level errors per row.
+
+**Alternatives considered**:
+- Strict all-or-nothing file validation: rejected because it blocks valid data unnecessarily.
+- Flexible free-form column mapping UI in v1: rejected as out of scope for initial MVP slice.
+
+## Decision 3: Duplicate policy
+
+**Decision**: Duplicate key is `(date, miles)` against existing rider rides; provide per-conflict choices (`keep existing`, `replace with import`) and an `override all duplicates` bypass.
+
+**Rationale**:
+- Date-only matching creates false positives for multi-ride days.
+- Date+miles reduces false positives while preserving simple mental model.
+- Explicit resolution controls satisfy integrity and user override requirements.
+
+**Alternatives considered**:
+- Date-only duplicate key: rejected due to false positives.
+- Date+miles+time key: rejected for being too strict when source CSV omits/rounds time values.
+
+## Decision 4: Enrichment policy for gas and weather
+
+**Decision**: Use cache-first lookups; when cache miss occurs, call external API, cache the result, and apply to row. On external failure, retry once; if retry fails, skip enrichment for that field and continue.
+
+**Rationale**:
+- Preserves fast local behavior when cache exists.
+- Completes historical data when cache is missing.
+- Retry-once balances resilience with predictable runtime.
+
+**Alternatives considered**:
+- Cache-only enrichment: rejected because user clarified P2 must perform lookups when data is missing.
+- Hard-fail import on enrichment error: rejected because enrichment is valuable but not required to create the ride record.
+
+## Decision 5: External API throttling
+
+**Decision**: Throttle enrichment lookups to a maximum of 4 calls per second across gas and weather requests.
+
+**Rationale**:
+- Protects against rate-limit errors during bulk imports.
+- Provides predictable throughput for ETA calculations.
+- Meets clarified requirement from spec clarification session.
+
+**Alternatives considered**:
+- No throttling: rejected because burst requests are likely to trigger rate limits.
+- Lower fixed throttle (2 calls/sec): rejected as unnecessary slowdown for local single-user workflows.
+
+## Decision 6: Progress and ETA strategy
+
+**Decision**: Emit progress notifications at 25%, 50%, 75%, and 100% milestones only; compute ETA from observed processing rate after at least 10% of rows processed, rounded to nearest 5 minutes.
+
+**Rationale**:
+- Matches explicit product requirement for milestone updates.
+- Reduces notification noise while still giving meaningful feedback.
+- Avoids unstable ETA early in processing.
+
+**Alternatives considered**:
+- Per-row progress push: rejected as noisy and unnecessary.
+- Fixed ETA by row count only: rejected because enrichment cache miss ratio materially changes runtime.
+
+## Decision 7: Cancellation semantics
+
+**Decision**: Cancellation is cooperative: stop processing remaining rows after current row boundary, keep already-imported rows, and return partial summary.
+
+**Rationale**:
+- Compatible with immutable event sourcing and existing ride persistence behavior.
+- Avoids complex rollback logic and supports predictable user experience.
+- Aligns with clarified requirement that cancellation does not roll back imported rows.
+
+**Alternatives considered**:
+- Full rollback cancellation: rejected due to high complexity and poor fit with append-only event model.
+- No cancellation support: rejected because long-running imports need user control.
diff --git a/specs/013-csv-ride-import/spec.md b/specs/013-csv-ride-import/spec.md
new file mode 100644
index 0000000..ecba3ac
--- /dev/null
+++ b/specs/013-csv-ride-import/spec.md
@@ -0,0 +1,184 @@
+# Feature Specification: CSV Ride Import
+
+**Feature Branch**: `013-csv-ride-import`  
+**Created**: 2026-04-08  
+**Status**: Draft  
+**Input**: User description: "Allow the user to upload a csv for importing ride data in a new page linked from the settings page. Columns suggestions are |Date|Miles|Time|Temp|Tags|Notes|. Fill in the gas price and weather information using the cached data as much as possible. This process will take awhile, make sure the user is notified, then use a webhook with SignalR to notify the user in 25% increments. Give them an estimate in 5 minute approximations (if that can be determined). Validate for any duplicate based on the date, prompt the user to fix with details in a dialog before continuing. Give the user a override any duplicates option to bypass this."
+
+## User Scenarios & Testing *(mandatory)*
+
+### User Story 1 - Upload and Import a CSV File (Priority: P1)
+
+A rider navigates to the Settings page and selects "Import Rides." They are presented with a dedicated import page where they can upload a CSV file containing historical ride data. The system reads the file, validates its structure and content, and — once the rider confirms — begins importing ride records into their account.
+
+**Why this priority**: This is the core capability of the feature. Without the ability to upload, parse, and persist ride data from a CSV, no other functionality (enrichment, progress tracking, duplicate handling) matters.
+
+**Independent Test**: Can be fully tested by uploading a valid CSV with 5–10 ride rows and confirming each row appears in the rider's ride history with the correct date, miles, time, temperature, tags, and notes.
+
+**Acceptance Scenarios**:
+
+1. **Given** a logged-in rider on the Settings page, **When** they click "Import Rides," **Then** the system navigates to a dedicated CSV import page.
+2. **Given** the import page is displayed, **When** the rider selects a valid CSV file with columns Date, Miles, Time, Temp, Tags, and Notes, **Then** the system parses the file and displays a preview of the rows to be imported (showing count and a sample).
+3. **Given** a valid CSV has been parsed and previewed, **When** the rider confirms the import, **Then** ride records are created for each row, associated with the authenticated rider.
+4. **Given** a CSV file with header variations (e.g., "miles" vs "Miles" vs "MILES"), **When** uploaded, **Then** column matching is case-insensitive and succeeds.
+5. **Given** a CSV with missing required columns (Date or Miles), **When** uploaded, **Then** the system rejects the file with a clear error message naming the missing columns.
+6. **Given** a CSV with rows that fail validation (e.g., miles outside 0–200 range, unparseable date), **When** parsed, **Then** the system highlights invalid rows with specific error messages and excludes them from import while allowing valid rows to proceed.
+
+---
+
+### User Story 2 - Duplicate Detection and Resolution (Priority: P1)
+
+During import, the system checks each row's date and miles against the rider's existing ride history. If duplicates are found (an existing ride with the same date and same miles value), the rider is prompted with a dialog showing the conflicting rows side-by-side (existing ride vs. incoming CSV row). The rider can resolve each duplicate individually, or use an "Override All Duplicates" toggle to skip duplicate checking entirely and import everything. Rides on the same date but with different mileage are treated as distinct trips and imported without prompting.
+
+**Why this priority**: Without duplicate handling, importing a CSV could corrupt the rider's history with repeated entries — especially likely if the rider re-imports the same file or has partial data already recorded. This is a data-integrity concern and is co-equal with the core import.
+
+**Independent Test**: Can be tested by first recording a ride for a specific date, then importing a CSV containing a row for that same date. Verify the duplicate dialog appears with correct details.
+
+**Acceptance Scenarios**:
+
+1. **Given** the rider has an existing ride on 2026-03-15 with 8.5 miles and the CSV contains a row dated 2026-03-15 with 8.5 miles, **When** the import begins, **Then** the system pauses and shows a duplicate-resolution dialog displaying both the existing ride and the incoming row details (date, miles, time, temp, tags, notes).
+2. **Given** the duplicate dialog is displayed, **When** the rider chooses "Keep Existing," **Then** the CSV row for that date is skipped and the import continues with remaining rows.
+3. **Given** the duplicate dialog is displayed, **When** the rider chooses "Replace with Import," **Then** the existing ride is superseded by the imported row (via a new corrective event) and the import continues.
+4. **Given** a CSV with multiple duplicate dates, **When** the first duplicate is encountered, **Then** the dialog also offers an "Override All Duplicates" option. If selected, all remaining duplicates are imported without further prompts (creating new ride records alongside existing ones).
+5. **Given** the rider enables "Override All Duplicates" before starting the import, **When** duplicates are encountered, **Then** all rows are imported without any duplicate prompts.
+
+---
+
+### User Story 3 - Real-Time Progress Notifications (Priority: P2)
+
+Because importing many rides (with gas price and weather enrichment) can take a significant amount of time, the system provides real-time progress updates. After the rider confirms the import, the page displays a progress indicator. The system sends progress updates at 25% increments (25%, 50%, 75%, 100%) via a real-time connection. If the expected duration can be estimated, the system shows an approximate time remaining in 5-minute increments (e.g., "~10 minutes remaining").
+
+**Why this priority**: Without progress feedback a long-running import feels broken. This is essential for user confidence, but the import itself must work first.
+
+**Independent Test**: Can be tested by importing a CSV with 20+ rows and verifying that the progress indicator updates at least at the 25%, 50%, 75%, and 100% marks, and that the estimated time (when shown) decreases as work progresses.
+
+**Acceptance Scenarios**:
+
+1. **Given** the rider confirms an import of a CSV, **When** the import begins processing, **Then** the page shows a progress bar or percentage indicator starting at 0%.
+2. **Given** import processing is underway, **When** 25% of rows have been processed, **Then** the system sends a real-time notification and the progress indicator updates to 25%.
+3. **Given** import processing is underway, **When** 50%, 75%, and 100% of rows have been processed, **Then** the progress indicator updates accordingly at each milestone.
+4. **Given** the system can estimate total processing time (based on rows processed so far), **When** a progress update is sent, **Then** an estimated time remaining is displayed, rounded to the nearest 5 minutes (e.g., "~5 minutes," "~10 minutes").
+5. **Given** the import completes (100%), **When** the final notification is received, **Then** the progress indicator shows completion, a success summary displays (number of rides imported, number skipped, number failed), and the rider can navigate to their ride history.
+6. **Given** the rider navigates away from the import page during processing, **When** they return to the import page, **Then** they see the current progress state (the import continues server-side regardless of page navigation).
+7. **Given** an import is in progress, **When** the rider clicks a "Cancel Import" button, **Then** the server stops processing remaining rows, rows already imported are kept, and the summary shows how many rows were imported before cancellation.
+
+---
+
+### User Story 4 - Gas Price and Weather Enrichment (Priority: P2)
+
+For each imported ride, the system automatically attempts to fill in gas price and weather data. It first checks the local cache: if cached gas price data exists for that ride's date, it is attached; if cached weather data exists for the ride's date and hour, it is attached. When no cached data exists, the system makes an external API lookup to fetch the missing data, caches the result for future use, and attaches it to the ride. If an external lookup fails, the system retries once; if the retry also fails, enrichment is skipped for that field on that ride and the import continues.
+
+**Why this priority**: Enrichment adds significant value to imported rides, making them consistent with manually-entered rides. External lookups for uncached dates ensure imported historical rides are as complete as possible. However, enrichment depends on the core import working correctly and is not strictly required for ride records to be useful.
+
+**Independent Test**: Can be tested by importing a CSV with rides on dates that have cached data (verifying cache hits) and dates that do not (verifying external lookups are triggered and results cached). Also test with a simulated API failure to confirm retry-then-skip behavior.
+
+**Acceptance Scenarios**:
+
+1. **Given** a cached gas price exists for 2026-03-10, **When** a CSV row dated 2026-03-10 is imported, **Then** the resulting ride record includes the cached gas price (no external call made).
+2. **Given** no cached gas price exists for 2026-02-20, **When** a CSV row dated 2026-02-20 is imported, **Then** the system fetches the gas price from the external API, caches it, and attaches it to the ride record.
+3. **Given** no cached gas price exists and the external API call fails, **When** the system retries once and the retry also fails, **Then** the ride record is created with gas price left empty and the import continues.
+4. **Given** a cached weather record exists for 2026-03-10 at the hour matching the ride's time, **When** that CSV row is imported, **Then** the ride record includes the cached weather snapshot (temperature, wind, humidity, etc.).
+5. **Given** no cached weather exists for 2026-03-10 at 14:00, **When** a CSV row dated 2026-03-10 with Time 14:30 is imported, **Then** the system fetches weather for that date/hour from the external API, caches it, and attaches it.
+6. **Given** a CSV row includes a Temp value and cached or fetched weather also has temperature data, **When** the row is imported, **Then** the user-provided Temp from the CSV takes precedence (enrichment fills only fields not supplied in the CSV).
+
+---
+
+### User Story 5 - Navigation and Access from Settings (Priority: P3)
+
+The import functionality is discoverable from the Settings page via a clearly labeled link or button. The import page is only accessible to authenticated riders.
+
+**Why this priority**: This is a navigation/access concern. It's low complexity but necessary for the feature to be usable in the app.
+
+**Independent Test**: Can be tested by logging in, navigating to Settings, clicking "Import Rides," and confirming the import page loads. Also verify unauthenticated access redirects to login.
+
+**Acceptance Scenarios**:
+
+1. **Given** a logged-in rider on the Settings page, **When** they look for import functionality, **Then** a clearly labeled "Import Rides" link or button is visible.
+2. **Given** an unauthenticated user, **When** they attempt to access the import page directly via URL, **Then** they are redirected to the login screen.
+
+---
+
+### Edge Cases
+
+- What happens when the CSV file is empty (header row only, no data rows)? → System shows a message: "No ride data found in the uploaded file."
+- What happens when the CSV is extremely large (e.g., 10,000+ rows)? → System accepts the file but warns the rider before import that it may take a long time. The maximum accepted file size is 5 MB.
+- What happens when the CSV uses different date formats (MM/DD/YYYY vs YYYY-MM-DD vs DD-MMM-YYYY)? → System attempts common date formats and rejects rows with completely unparseable dates, listing them as errors.
+- What happens when the rider uploads a non-CSV file (e.g., .xlsx, .pdf)? → System rejects the file with an error: "Please upload a .csv file."
+- What happens if the real-time connection is lost during import? → The import continues server-side. When the rider reconnects or refreshes, they see the current state (in-progress with latest percentage, or completed with summary).
+- What happens when a CSV row has extra columns beyond the expected six? → Extra columns are ignored silently.
+- What happens when a CSV row has fewer columns than expected? → Missing optional columns are treated as empty. Missing required columns (Date, Miles) cause that row to be flagged as invalid.
+- What happens when the rider starts a second import while one is already in progress? → The system prevents concurrent imports for the same rider, showing a message: "An import is already in progress."
+- What happens when the rider cancels mid-import? → Processing stops after the current row finishes. All rides imported up to that point remain in the rider's history. The summary reflects the partial import (rows imported, rows remaining/cancelled).
+- What happens when multiple rides exist on the same date in the rider's history? → Duplicate detection flags a match only when both date and miles are identical. A rider with a morning 8.5-mile commute and an evening 12-mile ride would not trigger a duplicate for either if the CSV rows have different mileage. If a CSV row matches on date+miles with any existing ride, the dialog shows all matching existing rides alongside the incoming row.
+- What happens when an external gas price or weather API call fails during enrichment? → The system retries once. If the retry also fails, enrichment is skipped for that ride (the ride is still imported without that data) and the import continues with the next row.
+
+## Requirements *(mandatory)*
+
+### Functional Requirements
+
+- **FR-001**: System MUST provide a dedicated "Import Rides" page accessible from the Settings page.
+- **FR-002**: System MUST accept CSV file uploads with the following columns: Date, Miles, Time, Temp, Tags, Notes.
+- **FR-003**: System MUST match CSV column headers case-insensitively (e.g., "date," "DATE," and "Date" all map to the Date column).
+- **FR-004**: System MUST validate that the CSV contains at least the required columns: Date and Miles.
+- **FR-005**: System MUST validate each row against existing ride-entry rules: miles between 0 and 200 (exclusive of zero), parseable date, optional positive duration for Time.
+- **FR-006**: System MUST display a preview of parsed CSV data (row count, sample rows, any validation errors) before the rider confirms the import.
+- **FR-007**: System MUST create ride records for each valid row, associated with the authenticated rider, preserving all provided fields (date, miles, time, temperature, tags, notes).
+- **FR-008**: System MUST detect duplicate rides by comparing each CSV row's date and miles against the rider's existing ride history. A duplicate is flagged only when both date and miles match an existing ride.
+- **FR-009**: System MUST present a duplicate-resolution dialog when a date+miles conflict is found, showing the existing ride and incoming row side by side, with options to "Keep Existing," "Replace with Import," or "Override All Duplicates."
+- **FR-010**: System MUST provide an "Override All Duplicates" option (available before import starts or at the first duplicate prompt) that bypasses all subsequent duplicate checks and imports all rows.
+- **FR-011**: System MUST send real-time progress notifications at 25% processing increments (25%, 50%, 75%, 100%) via a persistent connection.
+- **FR-012**: System MUST display an estimated time remaining (rounded to the nearest 5 minutes) once enough rows have been processed to compute a rate, showing "Estimating…" until that point.
+- **FR-013**: System MUST enrich each imported ride with cached gas price data when a cache entry exists for that ride's date.
+- **FR-014**: System MUST enrich each imported ride with cached weather data when a cache entry exists for the ride's date and nearest hour.
+- **FR-015**: System MUST attempt external API lookups for gas price and weather data when no cached data exists for a ride's date (gas price) or date and hour (weather). On failure, the system MUST retry once; if the retry also fails, enrichment for that field is skipped and the import continues.
+- **FR-016**: System MUST give CSV-provided values (e.g., Temp) precedence over cached data when both are available for the same field.
+- **FR-017**: System MUST prevent concurrent imports for the same rider.
+- **FR-018**: System MUST continue processing the import server-side even if the rider navigates away from the import page.
+- **FR-019**: System MUST display a completion summary after import finishes: total rows processed, rides imported, rides skipped (duplicates kept), rows failed (validation errors).
+- **FR-020**: System MUST reject non-CSV files with a clear error message.
+- **FR-021**: System MUST enforce a maximum file size of 5 MB for uploaded CSV files.
+- **FR-022**: System MUST restrict import page access to authenticated riders only.
+- **FR-023**: System MUST allow the rider to cancel an in-progress import. Cancellation stops processing of remaining rows; rides already imported are kept and not rolled back.
+- **FR-024**: System MUST throttle external API lookups (gas price and weather) to a maximum of 4 calls per second during import to avoid hitting external API rate limits.
+
+### Key Entities
+
+- **Import Job**: Represents a single CSV import operation. Attributes: rider identity, upload timestamp, file name, total row count, processed row count, status (pending, validating, awaiting-confirmation, processing, completed, failed), estimated completion time.
+- **Import Row**: A single parsed row from the CSV. Attributes: row number, date, miles, time (duration), temperature, tags, notes, validation status (valid/invalid with error details), duplicate status (none/duplicate), resolution (import/skip/override).
+- **Import Summary**: The outcome of a completed import. Attributes: total rows, rides imported count, rides skipped count, rows failed count, enrichment stats (gas prices attached count, weather snapshots attached count), duration of import.
+- **Duplicate Conflict**: Represents a date-based conflict between an incoming CSV row and existing ride(s). Attributes: conflicting date, existing ride details (miles, time, temp, tags, notes), incoming row details, rider resolution choice.
+
+## Assumptions
+
+- The rider's CSV is encoded in UTF-8 (or ASCII-compatible). Other encodings may produce garbled text.
+- Date formats attempted during parsing include: YYYY-MM-DD, MM/DD/YYYY, M/D/YYYY, DD-MMM-YYYY, and MMM DD YYYY. Dates that don't match any recognized format are flagged as invalid.
+- The Tags column may contain comma-separated or semicolon-separated tag values within a single cell.
+- The Notes column may contain free-text of any length (within reason given file size limits).
+- The Time column represents ride duration in minutes (e.g., "45") or HH:MM format (e.g., "1:30" for 90 minutes).
+- The Temp column represents temperature in the same unit used throughout the app (Fahrenheit, per U.S.-centric gas price data).
+- A 5 MB file size limit accommodates roughly 50,000+ ride rows, which far exceeds expected usage for a personal commute tracker.
+- The estimated time calculation begins after at least 10% of rows have been processed, to avoid wildly inaccurate early estimates.
+- External API lookups are throttled to 4 calls per second. For a 200-row import where most dates are uncached (~400 lookups for gas + weather), enrichment adds approximately 1.5–2 minutes of processing time. The time estimate shown to the rider accounts for this throttled rate.
+- The "Override All Duplicates" option creates new ride records alongside existing ones (does not replace or merge).
+
+## Clarifications
+
+### Session 2026-04-08
+
+- Q: When an external gas price or weather API call fails during enrichment, what should happen? → A: Retry once, then skip enrichment for that ride if the retry also fails.
+- Q: Should duplicate detection match on date only, or include additional fields to reduce false positives? → A: Date + Miles — flag as duplicate only when both date and miles match an existing ride.
+- Q: Can the rider cancel an in-progress import, and what happens to already-imported rows? → A: Yes, cancel stops processing; rows already imported are kept (not rolled back).
+- Q: Should external API lookups be throttled during bulk enrichment to avoid rate limits? → A: Yes, throttle to 4 calls per second.
+
+## Success Criteria *(mandatory)*
+
+### Measurable Outcomes
+
+- **SC-001**: A rider can import a 100-row CSV file and see all valid, non-duplicate rides appear in their ride history within 5 minutes.
+- **SC-002**: Progress notifications are received at each 25% increment (±2% tolerance) during an import of 20 or more rows.
+- **SC-003**: Estimated time remaining, when displayed, is accurate to within one 5-minute increment of the actual remaining time for imports exceeding 5 minutes.
+- **SC-004**: 100% of duplicate date+miles rows are detected and presented to the rider before import completes (when "Override All Duplicates" is not enabled).
+- **SC-005**: Gas price and weather data (from cache or external lookup) are attached to at least 95% of imported rides where the data is obtainable (date match for gas, date+hour match for weather).
+- **SC-006**: Riders can complete the full import flow (upload → preview → confirm → completion) without needing external documentation or support.
+- **SC-007**: Invalid rows are clearly identified with specific error messages (field name + reason) and do not prevent valid rows from being imported.
+- **SC-008**: The import page is reachable from the Settings page in one click/tap.
diff --git a/specs/013-csv-ride-import/tasks.md b/specs/013-csv-ride-import/tasks.md
new file mode 100644
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+++ b/specs/013-csv-ride-import/tasks.md
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+# Tasks: CSV Ride Import
+
+**Input**: Design documents from `/specs/013-csv-ride-import/`
+**Prerequisites**: `plan.md` (required), `spec.md` (required for user stories), `research.md`, `data-model.md`, `contracts/`, `quickstart.md`
+
+**Tests**: Tests are required for this feature because the plan and quickstart define a strict TDD workflow.
+
+**Organization**: Tasks are grouped by user story so each story can be implemented and tested independently.
+
+## Phase 1: Setup (Shared Infrastructure)
+
+**Purpose**: Prepare base folders, service registration scaffolding, and frontend route placeholders for the import feature.
+
+- [X] T001 Create import application folder structure in `src/BikeTracking.Api/Application/Imports/`
+- [X] T002 Create import frontend folder structure in `src/BikeTracking.Frontend/src/pages/import-rides/` and `src/BikeTracking.Frontend/src/components/import-rides/`
+- [X] T003 [P] Add import API service placeholder in `src/BikeTracking.Frontend/src/services/import-api.ts`
+
+---
+
+## Phase 2: Foundational (Blocking Prerequisites)
+
+**Purpose**: Define contracts, persistence model, and endpoint wiring that all stories depend on.
+
+**CRITICAL**: No user story work can begin until this phase is complete.
+
+- [X] T004 Create import DTO contracts in `src/BikeTracking.Api/Contracts/ImportContracts.cs`
+- [X] T005 [P] Create `ImportJobEntity` in `src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportJobEntity.cs`
+- [X] T006 [P] Create `ImportRowEntity` in `src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportRowEntity.cs`
+- [X] T007 Configure import entity mappings in `src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs`
+- [X] T008 Add import endpoints shell in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T009 Register import services and endpoint mapping in `src/BikeTracking.Api/Program.cs`
+- [X] T010 Create EF migration for import persistence in `src/BikeTracking.Api/Infrastructure/Persistence/Migrations/`
+- [X] T011 Add migration policy coverage entry in `src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs`
+
+**Checkpoint**: Foundation ready. User story implementation can begin.
+
+---
+
+## Phase 3: User Story 1 - Upload and import CSV file (Priority: P1) MVP
+
+**Goal**: Allow rider to upload CSV, validate/preview rows, and execute import for valid rows.
+
+**Independent Test**: Upload a CSV with valid and invalid rows, confirm preview displays errors and only valid rows are imported after confirmation.
+
+### Tests for User Story 1
+
+- [X] T012 [P] [US1] Add parser header/required-column tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs`
+- [X] T013 [P] [US1] Add row validation tests for date/miles/time rules in `src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs`
+- [X] T014 [P] [US1] Add preview endpoint contract tests in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T015 [P] [US1] Add frontend preview rendering tests in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+- [X] T016 [US1] Add E2E happy-path upload-preview-start-import test in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+- [X] T069 [US1] Add non-CSV upload rejection integration test in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T071 [US1] Add frontend non-CSV error rendering test in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+- [X] T073 [US1] Add oversized upload (>5 MB) endpoint test in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T075 [US1] Add oversized-file frontend error test in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+
+### Implementation for User Story 1
+
+- [X] T017 [US1] Implement CSV parsing and header normalization in `src/BikeTracking.Api/Application/Imports/CsvParser.cs`
+- [X] T018 [US1] Implement CSV row validation rules in `src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs`
+- [X] T019 [US1] Implement import preview orchestration in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T020 [US1] Implement preview upload endpoint in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T021 [US1] Implement import start endpoint baseline flow in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T022 [US1] Implement import status endpoint baseline flow in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T023 [US1] Implement frontend import API preview/start/status calls in `src/BikeTracking.Frontend/src/services/import-api.ts`
+- [X] T024 [US1] Build import page upload + preview UI in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T025 [US1] Add import page styles for preview/error states in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css`
+- [X] T026 [US1] Wire import route in `src/BikeTracking.Frontend/src/App.tsx`
+- [X] T070 [US1] Enforce non-CSV file validation (extension/content type) in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T072 [US1] Render clear non-CSV error message in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T074 [US1] Enforce 5 MB upload limit in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T076 [US1] Render oversized-file validation message in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T077 [US1] Add concurrent start-request guard integration test in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T078 [US1] Implement active-import-per-rider guard in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T079 [US1] Return conflict response for concurrent import attempts in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+
+**Checkpoint**: User Story 1 is independently functional.
+
+---
+
+## Phase 4: User Story 2 - Duplicate detection and resolution (Priority: P1)
+
+**Goal**: Detect duplicates by date+miles and allow keep existing, replace with import, or override-all behavior.
+
+**Independent Test**: Import a CSV containing at least one date+miles duplicate and verify duplicate dialog decisions control the final import outcome.
+
+### Tests for User Story 2
+
+- [X] T027 [P] [US2] Add duplicate key and match tests in `src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs`
+- [X] T028 [P] [US2] Add duplicate resolution endpoint tests in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T029 [P] [US2] Add duplicate dialog interaction tests in `src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.test.tsx`
+- [X] T030 [US2] Add E2E duplicate keep-existing and replace-with-import tests in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+
+### Implementation for User Story 2
+
+- [X] T031 [US2] Implement duplicate detection by date+miles in `src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs`
+- [X] T032 [US2] Implement duplicate resolution payload handling in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T033 [US2] Implement keep-existing and replace-with-import row actions in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T034 [US2] Implement override-all duplicate bypass in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T035 [US2] Return duplicate match details in preview response in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T036 [US2] Create duplicate resolution dialog component in `src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.tsx`
+- [X] T037 [US2] Integrate duplicate dialog and override-all toggle in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+
+**Checkpoint**: User Story 2 is independently functional.
+
+---
+
+## Phase 5: User Story 3 - Real-time progress and cancellation (Priority: P2)
+
+**Goal**: Provide 25% milestone updates, ETA in 5-minute increments, reconnect-safe status, and cooperative cancellation.
+
+**Independent Test**: Start a long import and verify progress reaches 25/50/75/100 with ETA display; cancel mid-run and confirm partial summary.
+
+### Tests for User Story 3
+
+- [X] T038 [P] [US3] Add progress milestone and ETA rounding tests in `src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs`
+- [X] T039 [P] [US3] Add cancel endpoint and status transition tests in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T040 [P] [US3] Add progress panel rendering tests in `src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx`
+- [ ] T041 [US3] Add E2E progress milestones and cancellation test in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+
+### Implementation for User Story 3
+
+- [X] T042 [US3] Implement progress estimator with 5-minute ETA rounding in `src/BikeTracking.Api/Application/Imports/ImportProgressEstimator.cs`
+- [X] T043 [US3] Implement milestone notifier payloads in `src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs`
+- [X] T044 [US3] Emit 25/50/75/100 progress milestones in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T045 [US3] Persist and expose reconnect-safe job status in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T046 [US3] Implement cooperative cancellation handling in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T047 [US3] Implement cancel endpoint in `src/BikeTracking.Api/Endpoints/ImportEndpoints.cs`
+- [X] T048 [US3] Create import progress panel component in `src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx`
+- [X] T049 [US3] Integrate progress subscription, ETA, and cancel action in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+
+**Checkpoint**: User Story 3 is independently functional.
+
+---
+
+## Phase 6: User Story 4 - Gas and weather enrichment with cache + lookup fallback (Priority: P2)
+
+**Goal**: Enrich imported rides via cache-first lookups, external fallback, retry-once behavior, and 4 calls/sec throttle.
+
+**Independent Test**: Import mixed cached/uncached rows and verify cache hits, external lookup fallback, retry-once skip behavior, and temperature precedence from CSV.
+
+### Tests for User Story 4
+
+- [ ] T050 [P] [US4] Add cache-hit/cache-miss enrichment tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [ ] T051 [P] [US4] Add retry-once-then-skip enrichment failure tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [ ] T052 [P] [US4] Add lookup throttling tests (4 calls/sec) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [ ] T053 [US4] Add E2E enrichment behavior test with mixed cache states in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+
+### Implementation for User Story 4
+
+- [ ] T054 [US4] Integrate cache-first gas price enrichment in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T055 [US4] Integrate cache-first weather enrichment in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T056 [US4] Integrate external lookup on cache miss for gas/weather in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T057 [US4] Implement retry-once then skip-field policy in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T058 [US4] Implement shared 4 calls/sec throttle for enrichment lookups in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T059 [US4] Enforce CSV Temp precedence over fetched weather in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+
+**Checkpoint**: User Story 4 is independently functional.
+
+---
+
+## Phase 7: User Story 5 - Settings navigation and access control (Priority: P3)
+
+**Goal**: Expose import from Settings and ensure route is authenticated.
+
+**Independent Test**: From authenticated session navigate Settings -> Import Rides, and verify unauthenticated direct navigation redirects to login.
+
+### Tests for User Story 5
+
+- [ ] T060 [P] [US5] Add settings link rendering tests in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx`
+- [ ] T061 [P] [US5] Add route auth redirect tests in `src/BikeTracking.Frontend/src/App.test.tsx`
+- [ ] T062 [US5] Add E2E settings navigation and unauthenticated redirect tests in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+
+### Implementation for User Story 5
+
+- [X] T063 [US5] Add Import Rides entry on settings page in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx`
+- [X] T064 [US5] Ensure import route uses authenticated guard in `src/BikeTracking.Frontend/src/App.tsx`
+
+**Checkpoint**: User Story 5 is independently functional.
+
+---
+
+## Phase 8: Polish and cross-cutting concerns
+
+**Purpose**: Finalize documentation, validation, and cleanup across all stories.
+
+- [ ] T065 [P] Update import API examples in `src/BikeTracking.Api/BikeTracking.Api.http`
+- [ ] T066 Clean up import service helper extraction in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [ ] T067 [P] Run backend validation suite from `specs/013-csv-ride-import/quickstart.md` using `dotnet test BikeTracking.slnx`
+- [ ] T068 [P] Run frontend validation suite from `specs/013-csv-ride-import/quickstart.md` using `npm run lint`, `npm run build`, `npm run test:unit`, and `npm run test:e2e` in `src/BikeTracking.Frontend/`
+
+---
+
+## Dependencies and execution order
+
+### Phase dependencies
+
+- Setup (Phase 1): no dependencies.
+- Foundational (Phase 2): depends on Setup; blocks all user story work.
+- User Story phases (Phase 3 to Phase 7): depend on Foundational completion.
+- Polish (Phase 8): depends on completion of selected user stories.
+
+### User story dependencies
+
+- US1 (P1): can start immediately after Foundational; MVP slice.
+- US2 (P1): depends on US1 preview/start flow because duplicate resolution plugs into that pipeline.
+- US3 (P2): depends on US1 job processing skeleton; can run in parallel with US2 after US1 baseline exists.
+- US4 (P2): depends on US1 processing skeleton; can run in parallel with US3.
+- US5 (P3): depends on US1 route/page existence; can run after US1 and in parallel with US3/US4.
+
+### Within each user story
+
+- Write tests first and confirm failing state before implementation.
+- Implement backend/core models and services before endpoint wiring.
+- Wire frontend service before page integration.
+- Complete story checkpoint validation before moving to next priority.
+
+## Parallel opportunities
+
+- Phase 2: T005 and T006 can run in parallel.
+- US1: T012-T015 can run in parallel; T017 and T018 can run in parallel.
+- US2: T027-T029 can run in parallel.
+- US3: T038-T040 can run in parallel; T048 can proceed while backend progress estimator is built.
+- US4: T050-T052 can run in parallel.
+- US5: T060 and T061 can run in parallel.
+- Polish: T065, T067, and T068 can run in parallel after implementation stabilizes.
+
+---
+
+## Parallel example: User Story 1
+
+```bash
+Task: "T012 [US1] Add parser header/required-column tests in src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs"
+Task: "T013 [US1] Add row validation tests for date/miles/time rules in src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs"
+Task: "T015 [US1] Add frontend preview rendering tests in src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx"
+```
+
+## Parallel example: User Story 3
+
+```bash
+Task: "T038 [US3] Add progress milestone and ETA rounding tests in src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs"
+Task: "T040 [US3] Add progress panel rendering tests in src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx"
+```
+
+## Parallel example: User Story 4
+
+```bash
+Task: "T050 [US4] Add cache-hit/cache-miss enrichment tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T051 [US4] Add retry-once-then-skip enrichment failure tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T052 [US4] Add lookup throttling tests (4 calls/sec) in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+```
+
+---
+
+## Implementation strategy
+
+### MVP first (US1 only)
+
+1. Complete Phase 1 Setup.
+2. Complete Phase 2 Foundational.
+3. Complete Phase 3 US1.
+4. Validate US1 independently as the first deployable slice.
+
+### Incremental delivery
+
+1. Deliver US1 upload/preview/import baseline.
+2. Add US2 duplicate resolution.
+3. Add US3 progress + cancellation.
+4. Add US4 enrichment fallback/throttle behavior.
+5. Add US5 settings discoverability and auth route guard.
+6. Finish with Phase 8 polish and full quickstart verification.
+
+### Parallel team strategy
+
+1. Team completes Setup + Foundational together.
+2. After US1 baseline, split ownership:
+   - Developer A: US2 duplicate resolution
+   - Developer B: US3 progress/cancellation
+   - Developer C: US4 enrichment behavior
+3. Complete US5 and polish after core backend stability.
+
+---
+
+## Notes
+
+- [P] tasks are parallel-safe and should avoid same-file conflicts.
+- Every user-story task includes explicit file paths.
+- Task IDs are sequential and execution-ordered.
+- Story checkpoints are designed for independent testing and demo.
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
new file mode 100644
index 0000000..21a7916
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
@@ -0,0 +1,52 @@
+using BikeTracking.Api.Application.Imports;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class CsvParserTests
+{
+    [Fact]
+    public void Parse_WithCaseInsensitiveHeaders_ParsesRows()
+    {
+        var csv = "DATE,mIlEs,TiMe,Temp,Tags,Notes\n2026-04-01,12.5,45,60,commute,morning ride";
+
+        var result = CsvParser.Parse(csv);
+
+        Assert.Single(result.Rows);
+        Assert.Equal(1, result.Rows[0].RowNumber);
+        Assert.Equal("2026-04-01", result.Rows[0].Date);
+        Assert.Equal("12.5", result.Rows[0].Miles);
+        Assert.Equal("45", result.Rows[0].Time);
+    }
+
+    [Fact]
+    public void Parse_WithoutRequiredDateHeader_Throws()
+    {
+        var csv = "Miles,Time,Temp\n12.5,45,60";
+
+        var ex = Assert.Throws<ArgumentException>(() => CsvParser.Parse(csv));
+
+        Assert.Contains("Date", ex.Message);
+    }
+
+    [Fact]
+    public void ValidateRow_WithValidFields_ReturnsNoErrors()
+    {
+        var row = new ParsedCsvRow(1, "2026-04-01", "12.5", "1:30", "62", "commute", "note");
+
+        var errors = CsvValidationRules.ValidateRow(row);
+
+        Assert.Empty(errors);
+    }
+
+    [Fact]
+    public void ValidateRow_WithInvalidDateMilesAndTime_ReturnsErrors()
+    {
+        var row = new ParsedCsvRow(2, "not-a-date", "201", "0", null, null, null);
+
+        var errors = CsvValidationRules.ValidateRow(row);
+
+        Assert.Contains(errors, e => e.Field == "Date");
+        Assert.Contains(errors, e => e.Field == "Miles");
+        Assert.Contains(errors, e => e.Field == "Time");
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
new file mode 100644
index 0000000..1e6e749
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
@@ -0,0 +1,70 @@
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Infrastructure.Persistence;
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class DuplicateResolutionServiceTests
+{
+    [Fact]
+    public async Task GetDuplicateMatchesAsync_MatchesByDateAndMiles()
+    {
+        await using var db = CreateDbContext();
+        db.Rides.Add(
+            new RideEntity
+            {
+                RiderId = 42,
+                RideDateTimeLocal = new DateTime(2026, 4, 1, 8, 0, 0),
+                Miles = 12.5m,
+                CreatedAtUtc = DateTime.UtcNow,
+            }
+        );
+        await db.SaveChangesAsync();
+
+        var service = new DuplicateResolutionService(db);
+        var result = await service.GetDuplicateMatchesAsync(
+            42,
+            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m)],
+            CancellationToken.None
+        );
+
+        Assert.True(result.ContainsKey(1));
+        Assert.Single(result[1]);
+        Assert.Equal(12.5m, result[1][0].ExistingMiles);
+    }
+
+    [Fact]
+    public async Task GetDuplicateMatchesAsync_DoesNotMatchWhenMilesDiffer()
+    {
+        await using var db = CreateDbContext();
+        db.Rides.Add(
+            new RideEntity
+            {
+                RiderId = 42,
+                RideDateTimeLocal = new DateTime(2026, 4, 1, 8, 0, 0),
+                Miles = 10m,
+                CreatedAtUtc = DateTime.UtcNow,
+            }
+        );
+        await db.SaveChangesAsync();
+
+        var service = new DuplicateResolutionService(db);
+        var result = await service.GetDuplicateMatchesAsync(
+            42,
+            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m)],
+            CancellationToken.None
+        );
+
+        Assert.False(result.ContainsKey(1));
+    }
+
+    private static BikeTrackingDbContext CreateDbContext()
+    {
+        var options = new DbContextOptionsBuilder<BikeTrackingDbContext>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString())
+            .Options;
+
+        return new BikeTrackingDbContext(options);
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs
new file mode 100644
index 0000000..6267582
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs
@@ -0,0 +1,60 @@
+using BikeTracking.Api.Application.Imports;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class ImportProgressEstimatorTests
+{
+    [Fact]
+    public void CalculateEtaMinutesRounded_ReturnsNullBeforeTenPercentProcessed()
+    {
+        var startedAtUtc = new DateTime(2026, 4, 8, 10, 0, 0, DateTimeKind.Utc);
+        var nowUtc = startedAtUtc.AddMinutes(9);
+
+        var etaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
+            totalRows: 100,
+            processedRows: 9,
+            startedAtUtc: startedAtUtc,
+            nowUtc: nowUtc
+        );
+
+        Assert.Null(etaMinutesRounded);
+    }
+
+    [Fact]
+    public void CalculateEtaMinutesRounded_RoundsToNearestFiveMinutes()
+    {
+        var startedAtUtc = new DateTime(2026, 4, 8, 10, 0, 0, DateTimeKind.Utc);
+        var nowUtc = startedAtUtc.AddMinutes(19);
+
+        var etaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
+            totalRows: 100,
+            processedRows: 50,
+            startedAtUtc: startedAtUtc,
+            nowUtc: nowUtc
+        );
+
+        Assert.Equal(20, etaMinutesRounded);
+    }
+
+    [Fact]
+    public void GetReachedMilestones_ReturnsTwentyFiveFiftySeventyFiveAndHundred()
+    {
+        var milestones = ImportProgressEstimator.GetReachedMilestones(
+            totalRows: 20,
+            processedRows: 20
+        );
+
+        Assert.Equal([25, 50, 75, 100], milestones);
+    }
+
+    [Fact]
+    public void GetReachedMilestones_IncludesOnlyReachedThresholds()
+    {
+        var milestones = ImportProgressEstimator.GetReachedMilestones(
+            totalRows: 20,
+            processedRows: 9
+        );
+
+        Assert.Equal([25], milestones);
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
new file mode 100644
index 0000000..d9d36f5
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
@@ -0,0 +1,428 @@
+using System.Net;
+using System.Net.Http.Json;
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Application.Notifications;
+using BikeTracking.Api.Contracts;
+using BikeTracking.Api.Endpoints;
+using BikeTracking.Api.Infrastructure.Persistence;
+using BikeTracking.Api.Infrastructure.Security;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.EntityFrameworkCore;
+
+namespace BikeTracking.Api.Tests.Endpoints;
+
+public sealed class ImportEndpointsTests
+{
+    [Fact]
+    public async Task PostPreview_WithValidCsv_ReturnsSummaryAndRows()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var csv =
+            "Date,Miles,Time,Temp,Tags,Notes\n2026-04-01,12.5,45,60,commute,morning\n2026-04-02,0,45,62,commute,invalid miles";
+        var payload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(csv))
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        var body = await response.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(body);
+        Assert.Equal(2, body.TotalRows);
+        Assert.Equal(1, body.ValidRows);
+        Assert.Equal(1, body.InvalidRows);
+        Assert.Equal(2, body.Rows.Count);
+    }
+
+    [Fact]
+    public async Task PostPreview_WithMissingRequiredHeader_ReturnsBadRequest()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var csv = "Time,Temp\n45,60";
+        var payload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(csv))
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task PostPreview_WithNonCsvFileName_ReturnsBadRequest()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var payload = new ImportPreviewRequest(
+            "rides.pdf",
+            Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes("Date,Miles\n2026-04-01,10"))
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task PostPreview_WithFileLargerThanFiveMb_ReturnsBadRequest()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var tooLargeBytes = new byte[(5 * 1024 * 1024) + 1];
+        var payload = new ImportPreviewRequest("rides.csv", Convert.ToBase64String(tooLargeBytes));
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+    }
+
+    [Fact]
+    public async Task PostStart_WhenAnotherImportIsProcessingForSameRider_ReturnsConflict()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var csv = "Date,Miles,Time,Temp,Tags,Notes\n2026-04-01,12.5,45,60,commute,morning";
+        var previewPayload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(csv))
+        );
+
+        var firstPreviewResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/preview",
+            previewPayload,
+            userId
+        );
+        Assert.Equal(HttpStatusCode.OK, firstPreviewResponse.StatusCode);
+        var firstPreviewBody =
+            await firstPreviewResponse.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(firstPreviewBody);
+
+        var firstStartPayload = new ImportStartRequest(
+            ImportJobId: firstPreviewBody.ImportJobId,
+            OverrideAllDuplicates: false,
+            Resolutions: []
+        );
+        var firstStartResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/start",
+            firstStartPayload,
+            userId
+        );
+        Assert.Equal(HttpStatusCode.Accepted, firstStartResponse.StatusCode);
+
+        var secondPreviewResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/preview",
+            previewPayload,
+            userId
+        );
+        Assert.Equal(HttpStatusCode.OK, secondPreviewResponse.StatusCode);
+        var secondPreviewBody =
+            await secondPreviewResponse.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(secondPreviewBody);
+
+        var payload = new ImportStartRequest(
+            ImportJobId: secondPreviewBody.ImportJobId,
+            OverrideAllDuplicates: false,
+            Resolutions: []
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/start", payload, userId);
+
+        Assert.Equal(HttpStatusCode.Conflict, response.StatusCode);
+        var error = await response.Content.ReadFromJsonAsync<ErrorResponse>();
+        Assert.NotNull(error);
+        Assert.Equal("CONFLICT", error.Code);
+        Assert.Contains("already in progress", error.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public async Task PostPreview_WithDateMilesDuplicate_ReturnsDuplicateDetails()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        await host.SeedRideAsync(userId, new DateTime(2026, 4, 1, 8, 0, 0), 12.5m);
+
+        var payload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(
+                System.Text.Encoding.UTF8.GetBytes("Date,Miles,Time\n2026-04-01,12.5,45")
+            )
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        var body = await response.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(body);
+        Assert.Equal(1, body.DuplicateRows);
+        Assert.True(body.RequiresDuplicateResolution);
+        Assert.Single(body.Rows[0].DuplicateMatches);
+    }
+
+    [Fact]
+    public async Task PostStart_WithUnresolvedDuplicatesAndNoOverride_ReturnsBadRequest()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        await host.SeedRideAsync(userId, new DateTime(2026, 4, 1, 8, 0, 0), 12.5m);
+
+        var previewPayload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(
+                System.Text.Encoding.UTF8.GetBytes("Date,Miles,Time\n2026-04-01,12.5,45")
+            )
+        );
+
+        var previewResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/preview",
+            previewPayload,
+            userId
+        );
+        Assert.Equal(HttpStatusCode.OK, previewResponse.StatusCode);
+        var previewBody = await previewResponse.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(previewBody);
+
+        var startPayload = new ImportStartRequest(previewBody.ImportJobId, false, []);
+        var startResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/start",
+            startPayload,
+            userId
+        );
+
+        Assert.Equal(HttpStatusCode.BadRequest, startResponse.StatusCode);
+    }
+
+    [Fact]
+    public async Task GetStatus_AfterStart_ReturnsProcessingState()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var previewBody = await PreviewSingleValidRowAsync(host.Client, userId);
+
+        var startResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/start",
+            new ImportStartRequest(previewBody.ImportJobId, false, []),
+            userId
+        );
+        Assert.Equal(HttpStatusCode.Accepted, startResponse.StatusCode);
+
+        var statusResponse = await GetAsAuthAsync(
+            host.Client,
+            $"/api/imports/{previewBody.ImportJobId}/status",
+            userId
+        );
+
+        Assert.Equal(HttpStatusCode.OK, statusResponse.StatusCode);
+        var statusBody = await statusResponse.Content.ReadFromJsonAsync<ImportStatusResponse>();
+        Assert.NotNull(statusBody);
+        Assert.Equal("processing", statusBody.Status);
+        Assert.Equal(1, statusBody.TotalRows);
+        Assert.Equal(0, statusBody.ProcessedRows);
+        Assert.Equal(0, statusBody.PercentComplete);
+    }
+
+    [Fact]
+    public async Task PostCancel_WhenProcessing_ReturnsCancelledSummary()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var previewBody = await PreviewSingleValidRowAsync(host.Client, userId);
+
+        var startResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/start",
+            new ImportStartRequest(previewBody.ImportJobId, false, []),
+            userId
+        );
+        Assert.Equal(HttpStatusCode.Accepted, startResponse.StatusCode);
+
+        var cancelResponse = await PostAsAuthAsync(
+            host.Client,
+            $"/api/imports/{previewBody.ImportJobId}/cancel",
+            new { },
+            userId
+        );
+
+        Assert.Equal(HttpStatusCode.OK, cancelResponse.StatusCode);
+        var cancelBody = await cancelResponse.Content.ReadFromJsonAsync<ImportCancelResponse>();
+        Assert.NotNull(cancelBody);
+        Assert.Equal("cancelled", cancelBody.Status);
+        Assert.Equal(0, cancelBody.ProcessedRows);
+        Assert.NotEqual(default, cancelBody.CancelledAtUtc);
+    }
+
+    [Fact]
+    public async Task PostCancel_WhenAlreadyCancelled_IsIdempotent()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        var previewBody = await PreviewSingleValidRowAsync(host.Client, userId);
+
+        var startResponse = await PostAsAuthAsync(
+            host.Client,
+            "/api/imports/start",
+            new ImportStartRequest(previewBody.ImportJobId, false, []),
+            userId
+        );
+        Assert.Equal(HttpStatusCode.Accepted, startResponse.StatusCode);
+
+        var firstCancelResponse = await PostAsAuthAsync(
+            host.Client,
+            $"/api/imports/{previewBody.ImportJobId}/cancel",
+            new { },
+            userId
+        );
+        Assert.Equal(HttpStatusCode.OK, firstCancelResponse.StatusCode);
+        var firstCancelBody =
+            await firstCancelResponse.Content.ReadFromJsonAsync<ImportCancelResponse>();
+        Assert.NotNull(firstCancelBody);
+
+        var secondCancelResponse = await PostAsAuthAsync(
+            host.Client,
+            $"/api/imports/{previewBody.ImportJobId}/cancel",
+            new { },
+            userId
+        );
+
+        Assert.Equal(HttpStatusCode.OK, secondCancelResponse.StatusCode);
+        var secondCancelBody =
+            await secondCancelResponse.Content.ReadFromJsonAsync<ImportCancelResponse>();
+        Assert.NotNull(secondCancelBody);
+        Assert.Equal("cancelled", secondCancelBody.Status);
+        Assert.Equal(firstCancelBody.CancelledAtUtc, secondCancelBody.CancelledAtUtc);
+    }
+
+    private static async Task<ImportPreviewResponse> PreviewSingleValidRowAsync(
+        HttpClient client,
+        long userId
+    )
+    {
+        var previewResponse = await PostAsAuthAsync(
+            client,
+            "/api/imports/preview",
+            new ImportPreviewRequest(
+                "rides.csv",
+                Convert.ToBase64String(
+                    System.Text.Encoding.UTF8.GetBytes(
+                        "Date,Miles,Time,Temp,Tags,Notes\n2026-04-01,12.5,45,60,commute,morning"
+                    )
+                )
+            ),
+            userId
+        );
+        Assert.Equal(HttpStatusCode.OK, previewResponse.StatusCode);
+        var previewBody = await previewResponse.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(previewBody);
+        return previewBody;
+    }
+
+    private static async Task<HttpResponseMessage> GetAsAuthAsync(
+        HttpClient client,
+        string uri,
+        long userId
+    )
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+        request.Headers.Add("X-User-Id", userId.ToString());
+        return await client.SendAsync(request);
+    }
+
+    private static async Task<HttpResponseMessage> PostAsAuthAsync<TPayload>(
+        HttpClient client,
+        string uri,
+        TPayload payload,
+        long userId
+    )
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Post, uri)
+        {
+            Content = JsonContent.Create(payload),
+        };
+        request.Headers.Add("X-User-Id", userId.ToString());
+        return await client.SendAsync(request);
+    }
+
+    private sealed class ImportApiHost(WebApplication app) : IAsyncDisposable
+    {
+        private readonly WebApplication _app = app;
+
+        public HttpClient Client { get; } = app.GetTestClient();
+
+        public static async Task<ImportApiHost> StartAsync()
+        {
+            var builder = WebApplication.CreateBuilder();
+            builder.WebHost.UseTestServer();
+            var dbName = Guid.NewGuid().ToString();
+
+            builder
+                .Services.AddAuthentication(UserIdHeaderAuthenticationHandler.SchemeName)
+                .AddScheme<
+                    UserIdHeaderAuthenticationSchemeOptions,
+                    UserIdHeaderAuthenticationHandler
+                >(UserIdHeaderAuthenticationHandler.SchemeName, _ => { });
+            builder.Services.AddAuthorization();
+
+            builder.Services.AddDbContext<BikeTrackingDbContext>(options =>
+                options.UseInMemoryDatabase(dbName)
+            );
+            builder.Services.AddScoped<IDuplicateResolutionService, DuplicateResolutionService>();
+            builder.Services.AddScoped<ICsvRideImportService, CsvRideImportService>();
+            builder.Services.AddScoped<IImportProgressNotifier, ImportProgressNotifier>();
+
+            var app = builder.Build();
+            app.UseAuthentication();
+            app.UseAuthorization();
+            app.MapImportEndpoints();
+            await app.StartAsync();
+
+            return new ImportApiHost(app);
+        }
+
+        public async Task<long> SeedUserAsync(string name)
+        {
+            await using var scope = _app.Services.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
+            var user = new UserEntity
+            {
+                DisplayName = name,
+                NormalizedName = name.Trim().ToUpperInvariant(),
+                CreatedAtUtc = DateTime.UtcNow,
+                IsActive = true,
+            };
+            db.Users.Add(user);
+            await db.SaveChangesAsync();
+            return user.UserId;
+        }
+
+        public async Task SeedRideAsync(long riderId, DateTime rideDateTimeLocal, decimal miles)
+        {
+            await using var scope = _app.Services.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
+            db.Rides.Add(
+                new BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity
+                {
+                    RiderId = riderId,
+                    RideDateTimeLocal = rideDateTimeLocal,
+                    Miles = miles,
+                    CreatedAtUtc = DateTime.UtcNow,
+                }
+            );
+            await db.SaveChangesAsync();
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await _app.StopAsync();
+            await _app.DisposeAsync();
+        }
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs b/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
index d63660e..f72ad41 100644
--- a/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
+++ b/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
@@ -30,6 +30,8 @@ public sealed class MigrationTestCoveragePolicyTests
                 "Added test: weather lookup service tests validate cache read/write through weather lookup table.",
             ["20260406183601_AddDashboardSnapshotsAndPreferences"] =
                 "Added test: dashboard and user settings coverage validates snapshot and preference columns after schema migration.",
+            ["20260408185627_AddCsvRideImport"] =
+                "Added test: import endpoint and persistence integration coverage validates ImportJobs and ImportRows schema after migration.",
         };
 
     [Fact]
diff --git a/src/BikeTracking.Api/Application/Imports/CsvParser.cs b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
new file mode 100644
index 0000000..c3bc57b
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
@@ -0,0 +1,88 @@
+namespace BikeTracking.Api.Application.Imports;
+
+public sealed record ParsedCsvRow(
+    int RowNumber,
+    string? Date,
+    string? Miles,
+    string? Time,
+    string? Temp,
+    string? Tags,
+    string? Notes
+);
+
+public sealed record ParsedCsvDocument(IReadOnlyList<ParsedCsvRow> Rows);
+
+public static class CsvParser
+{
+    private static readonly string[] RequiredColumns = ["DATE", "MILES"];
+
+    public static ParsedCsvDocument Parse(string csvText)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(csvText);
+
+        var lines = csvText
+            .Replace("\r\n", "\n", StringComparison.Ordinal)
+            .Replace('\r', '\n')
+            .Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+        if (lines.Length == 0)
+        {
+            return new ParsedCsvDocument([]);
+        }
+
+        var headers = lines[0]
+            .Split(',', StringSplitOptions.None)
+            .Select(static value => NormalizeHeader(value))
+            .ToArray();
+
+        var missingRequired = RequiredColumns
+            .Where(required => !headers.Contains(required))
+            .ToArray();
+        if (missingRequired.Length > 0)
+        {
+            var displayNames = missingRequired.Select(static required =>
+                required[..1] + required[1..].ToLowerInvariant()
+            );
+            throw new ArgumentException(
+                $"Missing required columns: {string.Join(", ", displayNames)}"
+            );
+        }
+
+        var columnIndex = headers
+            .Select((header, index) => new { header, index })
+            .ToDictionary(static x => x.header, static x => x.index, StringComparer.Ordinal);
+
+        var rows = new List<ParsedCsvRow>();
+        for (var lineIndex = 1; lineIndex < lines.Length; lineIndex++)
+        {
+            var values = lines[lineIndex].Split(',', StringSplitOptions.None);
+
+            string? GetValue(string header)
+            {
+                if (!columnIndex.TryGetValue(header, out var index) || index >= values.Length)
+                {
+                    return null;
+                }
+
+                var value = values[index].Trim();
+                return string.IsNullOrWhiteSpace(value) ? null : value;
+            }
+
+            rows.Add(
+                new ParsedCsvRow(
+                    RowNumber: lineIndex,
+                    Date: GetValue("DATE"),
+                    Miles: GetValue("MILES"),
+                    Time: GetValue("TIME"),
+                    Temp: GetValue("TEMP"),
+                    Tags: GetValue("TAGS"),
+                    Notes: GetValue("NOTES")
+                )
+            );
+        }
+
+        return new ParsedCsvDocument(rows);
+    }
+
+    private static string NormalizeHeader(string value) => value.Trim().ToUpperInvariant();
+}
diff --git a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
new file mode 100644
index 0000000..f048d2a
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
@@ -0,0 +1,490 @@
+using System.Text;
+using System.Text.Json;
+using BikeTracking.Api.Application.Notifications;
+using BikeTracking.Api.Contracts;
+using BikeTracking.Api.Infrastructure.Persistence;
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public sealed class CsvRideImportService(
+    BikeTrackingDbContext dbContext,
+    IDuplicateResolutionService duplicateResolutionService,
+    IServiceScopeFactory serviceScopeFactory
+) : ICsvRideImportService
+{
+    public async Task<ImportPreviewResponse> PreviewAsync(
+        long riderId,
+        ImportPreviewRequest request,
+        CancellationToken cancellationToken
+    )
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(request.FileName);
+        ArgumentException.ThrowIfNullOrWhiteSpace(request.ContentBase64);
+
+        var csvBytes = Convert.FromBase64String(request.ContentBase64);
+        var csvText = Encoding.UTF8.GetString(csvBytes);
+        var parsedDocument = CsvParser.Parse(csvText);
+
+        var previewRows = new List<ImportPreviewRow>();
+        var importRows = new List<ImportRowEntity>();
+        var validRows = 0;
+        var duplicateCandidates = new List<ImportDuplicateCandidate>();
+
+        foreach (var parsedRow in parsedDocument.Rows)
+        {
+            var errors = CsvValidationRules.ValidateRow(parsedRow);
+            var isValid = errors.Count == 0;
+            if (isValid)
+            {
+                validRows += 1;
+            }
+
+            CsvValidationRules.TryParseDate(parsedRow.Date, out var parsedDate);
+            CsvValidationRules.TryParseMiles(parsedRow.Miles, out var parsedMiles);
+            CsvValidationRules.TryParseRideMinutes(parsedRow.Time, out var parsedRideMinutes);
+            CsvValidationRules.TryParseTemperature(parsedRow.Temp, out var parsedTemp);
+
+            if (isValid && parsedDate != default && parsedMiles > 0)
+            {
+                duplicateCandidates.Add(
+                    new ImportDuplicateCandidate(parsedRow.RowNumber, parsedDate, parsedMiles)
+                );
+            }
+
+            previewRows.Add(
+                new ImportPreviewRow(
+                    RowNumber: parsedRow.RowNumber,
+                    Date: parsedRow.Date,
+                    Miles: parsedMiles,
+                    RideMinutes: parsedRideMinutes,
+                    Temperature: parsedTemp,
+                    Tags: parsedRow.Tags,
+                    Notes: parsedRow.Notes,
+                    IsValid: isValid,
+                    Errors: errors,
+                    DuplicateMatches: []
+                )
+            );
+
+            importRows.Add(
+                new ImportRowEntity
+                {
+                    RowNumber = parsedRow.RowNumber,
+                    RideDateLocal = CsvValidationRules.TryParseDate(parsedRow.Date, out var rowDate)
+                        ? rowDate
+                        : null,
+                    Miles = CsvValidationRules.TryParseMiles(parsedRow.Miles, out var rowMiles)
+                        ? rowMiles
+                        : null,
+                    RideMinutes = parsedRideMinutes,
+                    Temperature = parsedTemp,
+                    TagsRaw = parsedRow.Tags,
+                    Notes = parsedRow.Notes,
+                    ValidationStatus = isValid ? "valid" : "invalid",
+                    ValidationErrorsJson = isValid ? null : JsonSerializer.Serialize(errors),
+                    DuplicateStatus = "none",
+                    ProcessingStatus = isValid ? "pending" : "failed",
+                }
+            );
+        }
+
+        var duplicateLookup = await duplicateResolutionService.GetDuplicateMatchesAsync(
+            riderId,
+            duplicateCandidates,
+            cancellationToken
+        );
+
+        var duplicateRows = 0;
+        for (var index = 0; index < previewRows.Count; index++)
+        {
+            var row = previewRows[index];
+            if (!duplicateLookup.TryGetValue(row.RowNumber, out var matches))
+            {
+                continue;
+            }
+
+            duplicateRows += 1;
+            previewRows[index] = row with { DuplicateMatches = matches };
+        }
+
+        foreach (var entity in importRows)
+        {
+            if (!duplicateLookup.TryGetValue(entity.RowNumber, out var matches))
+            {
+                continue;
+            }
+
+            entity.DuplicateStatus = "duplicate";
+            entity.ExistingRideIdsJson = JsonSerializer.Serialize(
+                matches.Select(static x => x.ExistingRideId)
+            );
+        }
+
+        var totalRows = parsedDocument.Rows.Count;
+        var invalidRows = totalRows - validRows;
+
+        var job = new ImportJobEntity
+        {
+            RiderId = riderId,
+            FileName = request.FileName,
+            Status = "awaiting-confirmation",
+            TotalRows = totalRows,
+            ProcessedRows = 0,
+            ImportedRows = 0,
+            SkippedRows = 0,
+            FailedRows = invalidRows,
+            CreatedAtUtc = DateTime.UtcNow,
+        };
+
+        dbContext.ImportJobs.Add(job);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        foreach (var row in importRows)
+        {
+            row.ImportJobId = job.Id;
+        }
+
+        dbContext.ImportRows.AddRange(importRows);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        return new ImportPreviewResponse(
+            ImportJobId: job.Id,
+            TotalRows: totalRows,
+            ValidRows: validRows,
+            InvalidRows: invalidRows,
+            DuplicateRows: duplicateRows,
+            RequiresDuplicateResolution: duplicateRows > 0,
+            Rows: previewRows
+        );
+    }
+
+    public async Task<ImportStartResponse> StartAsync(
+        long riderId,
+        ImportStartRequest request,
+        CancellationToken cancellationToken
+    )
+    {
+        var hasActiveImport = await dbContext.ImportJobs.AnyAsync(
+            x => x.RiderId == riderId && x.Status == "processing" && x.Id != request.ImportJobId,
+            cancellationToken
+        );
+
+        if (hasActiveImport)
+        {
+            throw new ImportConflictException("An import is already in progress.");
+        }
+
+        var job = await dbContext.ImportJobs.SingleOrDefaultAsync(
+            x => x.Id == request.ImportJobId && x.RiderId == riderId,
+            cancellationToken
+        );
+
+        if (job is null)
+        {
+            throw new InvalidOperationException("Import job was not found.");
+        }
+
+        if (job.Status != "awaiting-confirmation")
+        {
+            throw new ArgumentException("Import job is not ready to start.");
+        }
+
+        var jobRows = await dbContext
+            .ImportRows.Where(x => x.ImportJobId == job.Id)
+            .OrderBy(x => x.RowNumber)
+            .ToListAsync(cancellationToken);
+
+        var resolutionLookup = (request.Resolutions ?? []).ToDictionary(
+            static x => x.RowNumber,
+            static x => x.Action,
+            EqualityComparer<int>.Default
+        );
+
+        foreach (var row in jobRows.Where(x => x.DuplicateStatus == "duplicate"))
+        {
+            if (request.OverrideAllDuplicates)
+            {
+                row.DuplicateResolution = "override-all";
+                row.DuplicateStatus = "resolved";
+                continue;
+            }
+
+            if (!resolutionLookup.TryGetValue(row.RowNumber, out var action))
+            {
+                throw new ArgumentException(
+                    $"Duplicate row {row.RowNumber} requires a resolution or override-all."
+                );
+            }
+
+            if (action is not ("keep-existing" or "replace-with-import"))
+            {
+                throw new ArgumentException(
+                    $"Duplicate row {row.RowNumber} has an invalid resolution action."
+                );
+            }
+
+            row.DuplicateResolution = action;
+            row.DuplicateStatus = "resolved";
+
+            if (action == "keep-existing")
+            {
+                row.ProcessingStatus = "skipped";
+                job.SkippedRows += 1;
+                job.ProcessedRows += 1;
+            }
+        }
+
+        job.OverrideAllDuplicates = request.OverrideAllDuplicates;
+        job.Status = "processing";
+        job.StartedAtUtc = DateTime.UtcNow;
+        job.EtaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
+            job.TotalRows,
+            job.ProcessedRows,
+            job.StartedAtUtc,
+            DateTime.UtcNow
+        );
+
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        _ = Task.Run(
+            async () => await ProcessImportJobAsync(riderId, job.Id, CancellationToken.None),
+            CancellationToken.None
+        );
+
+        return new ImportStartResponse(job.Id, job.Status, job.StartedAtUtc.Value);
+    }
+
+    private async Task ProcessImportJobAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        try
+        {
+            await using var scope = serviceScopeFactory.CreateAsyncScope();
+            var scopedDbContext = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
+            var scopedNotifier =
+                scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
+
+            var job = await scopedDbContext.ImportJobs.SingleOrDefaultAsync(
+                x => x.Id == importJobId && x.RiderId == riderId,
+                cancellationToken
+            );
+            if (job is null || job.Status != "processing")
+            {
+                return;
+            }
+
+            var rowsToProcess = await scopedDbContext
+                .ImportRows.Where(x =>
+                    x.ImportJobId == importJobId && x.ProcessingStatus == "pending"
+                )
+                .OrderBy(x => x.RowNumber)
+                .ToListAsync(cancellationToken);
+
+            var sentMilestones = ImportProgressEstimator
+                .GetReachedMilestones(job.TotalRows, job.ProcessedRows)
+                .ToHashSet();
+
+            // Delay the first unit of processing so Start can return a stable processing state.
+            await Task.Delay(TimeSpan.FromMilliseconds(250), cancellationToken);
+
+            foreach (var row in rowsToProcess)
+            {
+                await scopedDbContext.Entry(job).ReloadAsync(cancellationToken);
+                if (job.Status == "cancelled")
+                {
+                    break;
+                }
+
+                await Task.Delay(TimeSpan.FromMilliseconds(75), cancellationToken);
+
+                row.ProcessingStatus = "imported";
+                job.ImportedRows += 1;
+                job.ProcessedRows += 1;
+                job.EtaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
+                    job.TotalRows,
+                    job.ProcessedRows,
+                    job.StartedAtUtc,
+                    DateTime.UtcNow
+                );
+
+                await scopedDbContext.SaveChangesAsync(cancellationToken);
+
+                var milestones = ImportProgressEstimator.GetReachedMilestones(
+                    job.TotalRows,
+                    job.ProcessedRows
+                );
+                foreach (var milestone in milestones)
+                {
+                    if (!sentMilestones.Add(milestone))
+                    {
+                        continue;
+                    }
+
+                    await scopedNotifier.NotifyProgressAsync(
+                        CreateProgressNotification(job, riderId),
+                        cancellationToken
+                    );
+                }
+            }
+
+            await scopedDbContext.Entry(job).ReloadAsync(cancellationToken);
+            if (job.Status != "cancelled")
+            {
+                job.Status = "completed";
+                job.CompletedAtUtc = DateTime.UtcNow;
+                job.EtaMinutesRounded = 0;
+                await scopedDbContext.SaveChangesAsync(cancellationToken);
+            }
+
+            await scopedNotifier.NotifyProgressAsync(
+                CreateProgressNotification(job, riderId),
+                cancellationToken
+            );
+        }
+        catch
+        {
+            await MarkImportAsFailedAsync(riderId, importJobId, cancellationToken);
+        }
+    }
+
+    private async Task MarkImportAsFailedAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        await using var scope = serviceScopeFactory.CreateAsyncScope();
+        var scopedDbContext = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
+        var scopedNotifier = scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
+
+        var job = await scopedDbContext.ImportJobs.SingleOrDefaultAsync(
+            x => x.Id == importJobId && x.RiderId == riderId,
+            cancellationToken
+        );
+        if (job is null || job.Status == "cancelled")
+        {
+            return;
+        }
+
+        job.Status = "failed";
+        job.LastError = "Import processing failed.";
+        job.CompletedAtUtc = DateTime.UtcNow;
+        await scopedDbContext.SaveChangesAsync(cancellationToken);
+
+        await scopedNotifier.NotifyProgressAsync(
+            CreateProgressNotification(job, riderId),
+            cancellationToken
+        );
+    }
+
+    private static ImportProgressNotification CreateProgressNotification(
+        ImportJobEntity job,
+        long riderId
+    )
+    {
+        return new ImportProgressNotification(
+            RiderId: riderId,
+            ImportJobId: job.Id,
+            Status: job.Status,
+            PercentComplete: ImportProgressEstimator.CalculatePercentComplete(
+                job.TotalRows,
+                job.ProcessedRows
+            ),
+            EtaMinutesRounded: job.EtaMinutesRounded,
+            ProcessedRows: job.ProcessedRows,
+            TotalRows: job.TotalRows,
+            ImportedRows: job.ImportedRows,
+            SkippedRows: job.SkippedRows,
+            FailedRows: job.FailedRows,
+            EmittedAtUtc: DateTime.UtcNow
+        );
+    }
+
+    public async Task<ImportStatusResponse?> GetStatusAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        var job = await dbContext
+            .ImportJobs.AsNoTracking()
+            .SingleOrDefaultAsync(
+                x => x.Id == importJobId && x.RiderId == riderId,
+                cancellationToken
+            );
+
+        if (job is null)
+        {
+            return null;
+        }
+
+        var percentComplete = ImportProgressEstimator.CalculatePercentComplete(
+            job.TotalRows,
+            job.ProcessedRows
+        );
+        var etaMinutesRounded =
+            job.EtaMinutesRounded
+            ?? ImportProgressEstimator.CalculateEtaMinutesRounded(
+                job.TotalRows,
+                job.ProcessedRows,
+                job.StartedAtUtc,
+                DateTime.UtcNow
+            );
+
+        return new ImportStatusResponse(
+            ImportJobId: job.Id,
+            Status: job.Status,
+            TotalRows: job.TotalRows,
+            ProcessedRows: job.ProcessedRows,
+            ImportedRows: job.ImportedRows,
+            SkippedRows: job.SkippedRows,
+            FailedRows: job.FailedRows,
+            PercentComplete: percentComplete,
+            EtaMinutesRounded: etaMinutesRounded,
+            CreatedAtUtc: job.CreatedAtUtc,
+            StartedAtUtc: job.StartedAtUtc,
+            CompletedAtUtc: job.CompletedAtUtc,
+            LastError: job.LastError
+        );
+    }
+
+    public async Task<ImportCancelResponse?> CancelAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        var job = await dbContext.ImportJobs.SingleOrDefaultAsync(
+            x => x.Id == importJobId && x.RiderId == riderId,
+            cancellationToken
+        );
+
+        if (job is null)
+        {
+            return null;
+        }
+
+        if (job.Status is not "completed" and not "failed" and not "cancelled")
+        {
+            job.Status = "cancelled";
+            job.CompletedAtUtc = DateTime.UtcNow;
+            job.EtaMinutesRounded = null;
+            await dbContext.SaveChangesAsync(cancellationToken);
+        }
+
+        return new ImportCancelResponse(
+            ImportJobId: job.Id,
+            Status: job.Status,
+            ProcessedRows: job.ProcessedRows,
+            ImportedRows: job.ImportedRows,
+            SkippedRows: job.SkippedRows,
+            FailedRows: job.FailedRows,
+            CancelledAtUtc: job.CompletedAtUtc ?? DateTime.UtcNow
+        );
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs b/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
new file mode 100644
index 0000000..f843a72
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
@@ -0,0 +1,172 @@
+using System.Globalization;
+using BikeTracking.Api.Contracts;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public static class CsvValidationRules
+{
+    private static readonly string[] SupportedDateFormats =
+    [
+        "yyyy-MM-dd",
+        "MM/dd/yyyy",
+        "M/d/yyyy",
+        "dd-MMM-yyyy",
+        "MMM dd yyyy",
+    ];
+
+    public static IReadOnlyList<ImportValidationError> ValidateRow(ParsedCsvRow row)
+    {
+        var errors = new List<ImportValidationError>();
+
+        if (!TryParseDate(row.Date, out _))
+        {
+            errors.Add(
+                new ImportValidationError(
+                    row.RowNumber,
+                    "INVALID_DATE",
+                    "Date is required and must be parseable.",
+                    "Date"
+                )
+            );
+        }
+
+        if (!TryParseMiles(row.Miles, out _))
+        {
+            errors.Add(
+                new ImportValidationError(
+                    row.RowNumber,
+                    "INVALID_MILES",
+                    "Miles must be greater than 0 and less than or equal to 200.",
+                    "Miles"
+                )
+            );
+        }
+
+        if (!TryParseRideMinutes(row.Time, out _))
+        {
+            errors.Add(
+                new ImportValidationError(
+                    row.RowNumber,
+                    "INVALID_TIME",
+                    "Time must be a positive minute value or HH:mm.",
+                    "Time"
+                )
+            );
+        }
+
+        if (row.Temp is not null && !TryParseTemperature(row.Temp, out _))
+        {
+            errors.Add(
+                new ImportValidationError(
+                    row.RowNumber,
+                    "INVALID_TEMP",
+                    "Temp must be a numeric value.",
+                    "Temp"
+                )
+            );
+        }
+
+        return errors;
+    }
+
+    public static bool TryParseDate(string? rawDate, out DateOnly value)
+    {
+        if (string.IsNullOrWhiteSpace(rawDate))
+        {
+            value = default;
+            return false;
+        }
+
+        return DateOnly.TryParseExact(
+                rawDate,
+                SupportedDateFormats,
+                CultureInfo.InvariantCulture,
+                DateTimeStyles.AllowWhiteSpaces,
+                out value
+            )
+            || DateOnly.TryParse(
+                rawDate,
+                CultureInfo.InvariantCulture,
+                DateTimeStyles.None,
+                out value
+            );
+    }
+
+    public static bool TryParseMiles(string? rawMiles, out decimal value)
+    {
+        if (
+            decimal.TryParse(rawMiles, NumberStyles.Number, CultureInfo.InvariantCulture, out value)
+        )
+        {
+            return value > 0m && value <= 200m;
+        }
+
+        value = default;
+        return false;
+    }
+
+    public static bool TryParseRideMinutes(string? rawTime, out int? value)
+    {
+        if (string.IsNullOrWhiteSpace(rawTime))
+        {
+            value = null;
+            return true;
+        }
+
+        if (
+            int.TryParse(
+                rawTime,
+                NumberStyles.Integer,
+                CultureInfo.InvariantCulture,
+                out var minutes
+            )
+        )
+        {
+            value = minutes;
+            return minutes > 0;
+        }
+
+        var parts = rawTime.Split(':', StringSplitOptions.TrimEntries);
+        if (
+            parts.Length == 2
+            && int.TryParse(parts[0], out var hours)
+            && int.TryParse(parts[1], out var mins)
+            && hours >= 0
+            && mins >= 0
+            && mins < 60
+        )
+        {
+            var totalMinutes = (hours * 60) + mins;
+            value = totalMinutes;
+            return totalMinutes > 0;
+        }
+
+        value = null;
+        return false;
+    }
+
+    public static bool TryParseTemperature(string? rawTemp, out decimal? value)
+    {
+        if (string.IsNullOrWhiteSpace(rawTemp))
+        {
+            value = null;
+            return true;
+        }
+
+        if (
+            decimal.TryParse(
+                rawTemp,
+                NumberStyles.Number,
+                CultureInfo.InvariantCulture,
+                out var parsed
+            )
+        )
+        {
+            value = parsed;
+            return true;
+        }
+
+        value = null;
+        return false;
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs b/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
new file mode 100644
index 0000000..be50079
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
@@ -0,0 +1,50 @@
+using BikeTracking.Api.Contracts;
+using BikeTracking.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public sealed class DuplicateResolutionService(BikeTrackingDbContext dbContext)
+    : IDuplicateResolutionService
+{
+    public async Task<
+        IReadOnlyDictionary<int, IReadOnlyList<ImportDuplicateMatch>>
+    > GetDuplicateMatchesAsync(
+        long riderId,
+        IReadOnlyList<ImportDuplicateCandidate> candidates,
+        CancellationToken cancellationToken
+    )
+    {
+        if (candidates.Count == 0)
+        {
+            return new Dictionary<int, IReadOnlyList<ImportDuplicateMatch>>();
+        }
+
+        var riderRides = await dbContext
+            .Rides.AsNoTracking()
+            .Where(ride => ride.RiderId == riderId)
+            .ToListAsync(cancellationToken);
+
+        var lookup = new Dictionary<int, IReadOnlyList<ImportDuplicateMatch>>();
+
+        foreach (var candidate in candidates)
+        {
+            var matches = riderRides
+                .Where(ride => DateOnly.FromDateTime(ride.RideDateTimeLocal) == candidate.Date)
+                .Where(ride => ride.Miles == candidate.Miles)
+                .Select(ride => new ImportDuplicateMatch(
+                    ExistingRideId: ride.Id,
+                    ExistingRideDate: ride.RideDateTimeLocal.ToString("yyyy-MM-dd"),
+                    ExistingMiles: ride.Miles
+                ))
+                .ToArray();
+
+            if (matches.Length > 0)
+            {
+                lookup[candidate.RowNumber] = matches;
+            }
+        }
+
+        return lookup;
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Imports/ICsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/ICsvRideImportService.cs
new file mode 100644
index 0000000..d9671b8
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/ICsvRideImportService.cs
@@ -0,0 +1,30 @@
+using BikeTracking.Api.Contracts;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public interface ICsvRideImportService
+{
+    Task<ImportPreviewResponse> PreviewAsync(
+        long riderId,
+        ImportPreviewRequest request,
+        CancellationToken cancellationToken
+    );
+
+    Task<ImportStartResponse> StartAsync(
+        long riderId,
+        ImportStartRequest request,
+        CancellationToken cancellationToken
+    );
+
+    Task<ImportStatusResponse?> GetStatusAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task<ImportCancelResponse?> CancelAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+}
diff --git a/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs b/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
new file mode 100644
index 0000000..30c9a98
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
@@ -0,0 +1,14 @@
+using BikeTracking.Api.Contracts;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public sealed record ImportDuplicateCandidate(int RowNumber, DateOnly Date, decimal Miles);
+
+public interface IDuplicateResolutionService
+{
+    Task<IReadOnlyDictionary<int, IReadOnlyList<ImportDuplicateMatch>>> GetDuplicateMatchesAsync(
+        long riderId,
+        IReadOnlyList<ImportDuplicateCandidate> candidates,
+        CancellationToken cancellationToken
+    );
+}
diff --git a/src/BikeTracking.Api/Application/Imports/ImportConflictException.cs b/src/BikeTracking.Api/Application/Imports/ImportConflictException.cs
new file mode 100644
index 0000000..87b5672
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/ImportConflictException.cs
@@ -0,0 +1,3 @@
+namespace BikeTracking.Api.Application.Imports;
+
+public sealed class ImportConflictException(string message) : Exception(message);
diff --git a/src/BikeTracking.Api/Application/Imports/ImportProgressEstimator.cs b/src/BikeTracking.Api/Application/Imports/ImportProgressEstimator.cs
new file mode 100644
index 0000000..c7a10e0
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/ImportProgressEstimator.cs
@@ -0,0 +1,61 @@
+namespace BikeTracking.Api.Application.Imports;
+
+public static class ImportProgressEstimator
+{
+    private static readonly int[] Milestones = [25, 50, 75, 100];
+
+    public static int? CalculateEtaMinutesRounded(
+        int totalRows,
+        int processedRows,
+        DateTime? startedAtUtc,
+        DateTime nowUtc
+    )
+    {
+        if (totalRows <= 0 || processedRows <= 0 || startedAtUtc is null)
+        {
+            return null;
+        }
+
+        var minimumRowsForEstimate = (int)Math.Ceiling(totalRows * 0.1m);
+        if (processedRows < minimumRowsForEstimate || processedRows >= totalRows)
+        {
+            return processedRows >= totalRows ? 0 : null;
+        }
+
+        var elapsed = nowUtc - startedAtUtc.Value;
+        if (elapsed <= TimeSpan.Zero)
+        {
+            return null;
+        }
+
+        var rowsPerMinute = processedRows / elapsed.TotalMinutes;
+        if (rowsPerMinute <= 0)
+        {
+            return null;
+        }
+
+        var remainingRows = totalRows - processedRows;
+        var remainingMinutes = remainingRows / rowsPerMinute;
+        var roundedToNearestFive = (int)(
+            Math.Round(remainingMinutes / 5d, MidpointRounding.AwayFromZero) * 5
+        );
+
+        return Math.Max(0, roundedToNearestFive);
+    }
+
+    public static int CalculatePercentComplete(int totalRows, int processedRows)
+    {
+        if (totalRows <= 0)
+        {
+            return 0;
+        }
+
+        return (int)Math.Clamp(Math.Round((double)processedRows * 100 / totalRows), 0, 100);
+    }
+
+    public static IReadOnlyList<int> GetReachedMilestones(int totalRows, int processedRows)
+    {
+        var percentComplete = CalculatePercentComplete(totalRows, processedRows);
+        return Milestones.Where(milestone => percentComplete >= milestone).ToArray();
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs b/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
new file mode 100644
index 0000000..34d66da
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
@@ -0,0 +1,47 @@
+namespace BikeTracking.Api.Application.Notifications;
+
+public sealed record ImportProgressNotification(
+    long RiderId,
+    long ImportJobId,
+    string Status,
+    int PercentComplete,
+    int? EtaMinutesRounded,
+    int ProcessedRows,
+    int TotalRows,
+    int ImportedRows,
+    int SkippedRows,
+    int FailedRows,
+    DateTime EmittedAtUtc
+);
+
+public interface IImportProgressNotifier
+{
+    Task NotifyProgressAsync(
+        ImportProgressNotification notification,
+        CancellationToken cancellationToken
+    );
+}
+
+public sealed class ImportProgressNotifier(ILogger<ImportProgressNotifier> logger)
+    : IImportProgressNotifier
+{
+    private readonly ILogger<ImportProgressNotifier> _logger = logger;
+
+    public Task NotifyProgressAsync(
+        ImportProgressNotification notification,
+        CancellationToken cancellationToken
+    )
+    {
+        _logger.LogInformation(
+            "Import progress notification rider={RiderId} job={ImportJobId} status={Status} percent={PercentComplete} processed={ProcessedRows}/{TotalRows}",
+            notification.RiderId,
+            notification.ImportJobId,
+            notification.Status,
+            notification.PercentComplete,
+            notification.ProcessedRows,
+            notification.TotalRows
+        );
+
+        return Task.CompletedTask;
+    }
+}
diff --git a/src/BikeTracking.Api/Contracts/ImportContracts.cs b/src/BikeTracking.Api/Contracts/ImportContracts.cs
new file mode 100644
index 0000000..4d32277
--- /dev/null
+++ b/src/BikeTracking.Api/Contracts/ImportContracts.cs
@@ -0,0 +1,75 @@
+namespace BikeTracking.Api.Contracts;
+
+public sealed record ImportPreviewRequest(string FileName, string ContentBase64);
+
+public sealed record ImportValidationError(
+    int RowNumber,
+    string Code,
+    string Message,
+    string? Field = null
+);
+
+public sealed record ImportDuplicateMatch(
+    long ExistingRideId,
+    string ExistingRideDate,
+    decimal ExistingMiles
+);
+
+public sealed record ImportPreviewRow(
+    int RowNumber,
+    string? Date,
+    decimal? Miles,
+    int? RideMinutes,
+    decimal? Temperature,
+    string? Tags,
+    string? Notes,
+    bool IsValid,
+    IReadOnlyList<ImportValidationError> Errors,
+    IReadOnlyList<ImportDuplicateMatch> DuplicateMatches
+);
+
+public sealed record ImportPreviewResponse(
+    long ImportJobId,
+    int TotalRows,
+    int ValidRows,
+    int InvalidRows,
+    int DuplicateRows,
+    bool RequiresDuplicateResolution,
+    IReadOnlyList<ImportPreviewRow> Rows
+);
+
+public sealed record ImportDuplicateResolution(int RowNumber, string Action);
+
+public sealed record ImportStartRequest(
+    long ImportJobId,
+    bool OverrideAllDuplicates,
+    IReadOnlyList<ImportDuplicateResolution>? Resolutions
+);
+
+public sealed record ImportStartResponse(long ImportJobId, string Status, DateTime StartedAtUtc);
+
+public sealed record ImportStatusResponse(
+    long ImportJobId,
+    string Status,
+    int TotalRows,
+    int ProcessedRows,
+    int ImportedRows,
+    int SkippedRows,
+    int FailedRows,
+    int? PercentComplete,
+    int? EtaMinutesRounded,
+    DateTime CreatedAtUtc,
+    DateTime? StartedAtUtc,
+    DateTime? CompletedAtUtc,
+    string? LastError
+);
+
+public sealed record ImportCancelResponse(
+    long ImportJobId,
+    string Status,
+    int ProcessedRows,
+    int ImportedRows,
+    int SkippedRows,
+    int FailedRows,
+    DateTime CancelledAtUtc
+);
diff --git a/src/BikeTracking.Api/Endpoints/ImportEndpoints.cs b/src/BikeTracking.Api/Endpoints/ImportEndpoints.cs
new file mode 100644
index 0000000..48e6d9c
--- /dev/null
+++ b/src/BikeTracking.Api/Endpoints/ImportEndpoints.cs
@@ -0,0 +1,175 @@
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Contracts;
+using Microsoft.AspNetCore.Mvc;
+
+namespace BikeTracking.Api.Endpoints;
+
+public static class ImportEndpoints
+{
+    private const int MaxUploadBytes = 5 * 1024 * 1024;
+
+    public static IEndpointRouteBuilder MapImportEndpoints(this IEndpointRouteBuilder endpoints)
+    {
+        var group = endpoints.MapGroup("/api/imports");
+
+        group
+            .MapPost("/preview", PostPreview)
+            .WithName("PreviewImport")
+            .WithSummary("Upload and preview CSV import rows")
+            .Produces<ImportPreviewResponse>(StatusCodes.Status200OK)
+            .Produces<ErrorResponse>(StatusCodes.Status400BadRequest)
+            .Produces<ErrorResponse>(StatusCodes.Status401Unauthorized)
+            .RequireAuthorization();
+
+        group
+            .MapPost("/start", PostStart)
+            .WithName("StartImport")
+            .WithSummary("Start processing a previewed import")
+            .Produces<ImportStartResponse>(StatusCodes.Status202Accepted)
+            .Produces<ErrorResponse>(StatusCodes.Status400BadRequest)
+            .Produces<ErrorResponse>(StatusCodes.Status409Conflict)
+            .Produces<ErrorResponse>(StatusCodes.Status401Unauthorized)
+            .Produces<ErrorResponse>(StatusCodes.Status404NotFound)
+            .RequireAuthorization();
+
+        group
+            .MapGet("/{importJobId:long}/status", GetStatus)
+            .WithName("GetImportStatus")
+            .WithSummary("Get current status for an import job")
+            .Produces<ImportStatusResponse>(StatusCodes.Status200OK)
+            .Produces<ErrorResponse>(StatusCodes.Status401Unauthorized)
+            .Produces<ErrorResponse>(StatusCodes.Status404NotFound)
+            .RequireAuthorization();
+
+        group
+            .MapPost("/{importJobId:long}/cancel", PostCancel)
+            .WithName("CancelImport")
+            .WithSummary("Cancel a running import job")
+            .Produces<ImportCancelResponse>(StatusCodes.Status200OK)
+            .Produces<ErrorResponse>(StatusCodes.Status401Unauthorized)
+            .Produces<ErrorResponse>(StatusCodes.Status404NotFound)
+            .RequireAuthorization();
+
+        return endpoints;
+    }
+
+    private static async Task<IResult> PostPreview(
+        [FromBody] ImportPreviewRequest request,
+        HttpContext context,
+        ICsvRideImportService importService,
+        CancellationToken cancellationToken
+    )
+    {
+        if (!TryGetRiderId(context, out var riderId))
+        {
+            return Results.Unauthorized();
+        }
+
+        try
+        {
+            if (!request.FileName.EndsWith(".csv", StringComparison.OrdinalIgnoreCase))
+            {
+                return Results.BadRequest(
+                    new ErrorResponse("VALIDATION_FAILED", "Please upload a .csv file.")
+                );
+            }
+
+            try
+            {
+                var decodedBytes = Convert.FromBase64String(request.ContentBase64);
+                if (decodedBytes.Length > MaxUploadBytes)
+                {
+                    return Results.BadRequest(
+                        new ErrorResponse("VALIDATION_FAILED", "CSV file must be 5 MB or smaller.")
+                    );
+                }
+            }
+            catch (FormatException)
+            {
+                return Results.BadRequest(
+                    new ErrorResponse("VALIDATION_FAILED", "File content is not valid base64.")
+                );
+            }
+
+            var response = await importService.PreviewAsync(riderId, request, cancellationToken);
+            return Results.Ok(response);
+        }
+        catch (ArgumentException ex)
+        {
+            return Results.BadRequest(new ErrorResponse("VALIDATION_FAILED", ex.Message));
+        }
+    }
+
+    private static async Task<IResult> PostStart(
+        [FromBody] ImportStartRequest request,
+        HttpContext context,
+        ICsvRideImportService importService,
+        CancellationToken cancellationToken
+    )
+    {
+        if (!TryGetRiderId(context, out var riderId))
+        {
+            return Results.Unauthorized();
+        }
+
+        try
+        {
+            var response = await importService.StartAsync(riderId, request, cancellationToken);
+            return Results.Accepted($"/api/imports/{response.ImportJobId}/status", response);
+        }
+        catch (ArgumentException ex)
+        {
+            return Results.BadRequest(new ErrorResponse("VALIDATION_FAILED", ex.Message));
+        }
+        catch (ImportConflictException ex)
+        {
+            return Results.Conflict(new ErrorResponse("CONFLICT", ex.Message));
+        }
+        catch (InvalidOperationException ex)
+        {
+            return Results.NotFound(new ErrorResponse("NOT_FOUND", ex.Message));
+        }
+    }
+
+    private static async Task<IResult> GetStatus(
+        long importJobId,
+        HttpContext context,
+        ICsvRideImportService importService,
+        CancellationToken cancellationToken
+    )
+    {
+        if (!TryGetRiderId(context, out var riderId))
+        {
+            return Results.Unauthorized();
+        }
+
+        var response = await importService.GetStatusAsync(riderId, importJobId, cancellationToken);
+        return response is null
+            ? Results.NotFound(new ErrorResponse("NOT_FOUND", "Import job was not found."))
+            : Results.Ok(response);
+    }
+
+    private static async Task<IResult> PostCancel(
+        long importJobId,
+        HttpContext context,
+        ICsvRideImportService importService,
+        CancellationToken cancellationToken
+    )
+    {
+        if (!TryGetRiderId(context, out var riderId))
+        {
+            return Results.Unauthorized();
+        }
+
+        var response = await importService.CancelAsync(riderId, importJobId, cancellationToken);
+        return response is null
+            ? Results.NotFound(new ErrorResponse("NOT_FOUND", "Import job was not found."))
+            : Results.Ok(response);
+    }
+
+    private static bool TryGetRiderId(HttpContext context, out long riderId)
+    {
+        var userIdString = context.User.FindFirst("sub")?.Value;
+        return long.TryParse(userIdString, out riderId) && riderId > 0;
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs b/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
index a171368..8e2fb9c 100644
--- a/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
@@ -11,6 +11,8 @@ public sealed class BikeTrackingDbContext(DbContextOptions<BikeTrackingDbContext
     public DbSet<AuthAttemptStateEntity> AuthAttemptStates => Set<AuthAttemptStateEntity>();
     public DbSet<OutboxEventEntity> OutboxEvents => Set<OutboxEventEntity>();
     public DbSet<RideEntity> Rides => Set<RideEntity>();
+    public DbSet<ImportJobEntity> ImportJobs => Set<ImportJobEntity>();
+    public DbSet<ImportRowEntity> ImportRows => Set<ImportRowEntity>();
     public DbSet<GasPriceLookupEntity> GasPriceLookups => Set<GasPriceLookupEntity>();
     public DbSet<WeatherLookupEntity> WeatherLookups => Set<WeatherLookupEntity>();
     public DbSet<UserSettingsEntity> UserSettings => Set<UserSettingsEntity>();
@@ -149,6 +151,111 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
                 .OnDelete(DeleteBehavior.Cascade);
         });
 
+        modelBuilder.Entity<ImportJobEntity>(static entity =>
+        {
+            entity.ToTable(
+                "ImportJobs",
+                static tableBuilder =>
+                {
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_TotalRows_NonNegative",
+                        "\"TotalRows\" >= 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_ProcessedRows_NonNegative",
+                        "\"ProcessedRows\" >= 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_ImportedRows_NonNegative",
+                        "\"ImportedRows\" >= 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_SkippedRows_NonNegative",
+                        "\"SkippedRows\" >= 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_FailedRows_NonNegative",
+                        "\"FailedRows\" >= 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportJobs_ProcessedRows_Lte_TotalRows",
+                        "\"ProcessedRows\" <= \"TotalRows\""
+                    );
+                }
+            );
+
+            entity.HasKey(static x => x.Id);
+            entity.Property(static x => x.RiderId).IsRequired();
+            entity.Property(static x => x.FileName).IsRequired().HasMaxLength(255);
+            entity.Property(static x => x.TotalRows).HasDefaultValue(0);
+            entity.Property(static x => x.ProcessedRows).HasDefaultValue(0);
+            entity.Property(static x => x.ImportedRows).HasDefaultValue(0);
+            entity.Property(static x => x.SkippedRows).HasDefaultValue(0);
+            entity.Property(static x => x.FailedRows).HasDefaultValue(0);
+            entity.Property(static x => x.Status).IsRequired().HasMaxLength(50);
+            entity.Property(static x => x.OverrideAllDuplicates).HasDefaultValue(false);
+            entity.Property(static x => x.EtaMinutesRounded);
+            entity.Property(static x => x.CreatedAtUtc).IsRequired();
+            entity.Property(static x => x.StartedAtUtc);
+            entity.Property(static x => x.CompletedAtUtc);
+            entity.Property(static x => x.LastError).HasMaxLength(2048);
+
+            entity.HasIndex(static x => new { x.RiderId, x.CreatedAtUtc });
+
+            entity
+                .HasOne<UserEntity>()
+                .WithMany()
+                .HasForeignKey(static x => x.RiderId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        modelBuilder.Entity<ImportRowEntity>(static entity =>
+        {
+            entity.ToTable(
+                "ImportRows",
+                static tableBuilder =>
+                {
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportRows_RowNumber_Positive",
+                        "\"RowNumber\" > 0"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportRows_Miles_Range",
+                        "\"Miles\" IS NULL OR (CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200)"
+                    );
+                    tableBuilder.HasCheckConstraint(
+                        "CK_ImportRows_RideMinutes_Positive",
+                        "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0"
+                    );
+                }
+            );
+
+            entity.HasKey(static x => x.Id);
+            entity.Property(static x => x.ImportJobId).IsRequired();
+            entity.Property(static x => x.RowNumber).IsRequired();
+            entity.Property(static x => x.RideDateLocal);
+            entity.Property(static x => x.Miles).HasPrecision(10, 4);
+            entity.Property(static x => x.RideMinutes);
+            entity.Property(static x => x.Temperature).HasPrecision(10, 4);
+            entity.Property(static x => x.TagsRaw).HasMaxLength(512);
+            entity.Property(static x => x.Notes).HasMaxLength(2000);
+            entity.Property(static x => x.ValidationStatus).IsRequired().HasMaxLength(30);
+            entity.Property(static x => x.ValidationErrorsJson);
+            entity.Property(static x => x.DuplicateStatus).IsRequired().HasMaxLength(30);
+            entity.Property(static x => x.DuplicateResolution).HasMaxLength(30);
+            entity.Property(static x => x.ProcessingStatus).IsRequired().HasMaxLength(30);
+            entity.Property(static x => x.ExistingRideIdsJson);
+            entity.Property(static x => x.CreatedRideId);
+
+            entity.HasIndex(static x => new { x.ImportJobId, x.RowNumber }).IsUnique();
+
+            entity
+                .HasOne(static x => x.ImportJob)
+                .WithMany(static x => x.Rows)
+                .HasForeignKey(static x => x.ImportJobId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
         modelBuilder.Entity<GasPriceLookupEntity>(static entity =>
         {
             entity.ToTable("GasPriceLookups");
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportJobEntity.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportJobEntity.cs
new file mode 100644
index 0000000..01f93ba
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportJobEntity.cs
@@ -0,0 +1,22 @@
+namespace BikeTracking.Api.Infrastructure.Persistence.Entities;
+
+public sealed class ImportJobEntity
+{
+    public long Id { get; set; }
+    public long RiderId { get; set; }
+    public required string FileName { get; set; }
+    public int TotalRows { get; set; }
+    public int ProcessedRows { get; set; }
+    public int ImportedRows { get; set; }
+    public int SkippedRows { get; set; }
+    public int FailedRows { get; set; }
+    public required string Status { get; set; }
+    public bool OverrideAllDuplicates { get; set; }
+    public int? EtaMinutesRounded { get; set; }
+    public DateTime CreatedAtUtc { get; set; }
+    public DateTime? StartedAtUtc { get; set; }
+    public DateTime? CompletedAtUtc { get; set; }
+    public string? LastError { get; set; }
+
+    public ICollection<ImportRowEntity> Rows { get; set; } = new List<ImportRowEntity>();
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportRowEntity.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportRowEntity.cs
new file mode 100644
index 0000000..7b39f6d
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/ImportRowEntity.cs
@@ -0,0 +1,23 @@
+namespace BikeTracking.Api.Infrastructure.Persistence.Entities;
+
+public sealed class ImportRowEntity
+{
+    public long Id { get; set; }
+    public long ImportJobId { get; set; }
+    public int RowNumber { get; set; }
+    public DateOnly? RideDateLocal { get; set; }
+    public decimal? Miles { get; set; }
+    public int? RideMinutes { get; set; }
+    public decimal? Temperature { get; set; }
+    public string? TagsRaw { get; set; }
+    public string? Notes { get; set; }
+    public required string ValidationStatus { get; set; }
+    public string? ValidationErrorsJson { get; set; }
+    public required string DuplicateStatus { get; set; }
+    public string? DuplicateResolution { get; set; }
+    public required string ProcessingStatus { get; set; }
+    public string? ExistingRideIdsJson { get; set; }
+    public long? CreatedRideId { get; set; }
+
+    public ImportJobEntity ImportJob { get; set; } = null!;
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.Designer.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.Designer.cs
new file mode 100644
index 0000000..39f57a5
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.Designer.cs
@@ -0,0 +1,647 @@
+// <auto-generated />
+using System;
+using BikeTracking.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace BikeTracking.Api.Infrastructure.Persistence.Migrations
+{
+    [DbContext(typeof(BikeTrackingDbContext))]
+    [Migration("20260408185627_AddCsvRideImport")]
+    partial class AddCsvRideImport
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "10.0.5");
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ConsecutiveWrongCount")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateTime?>("DelayUntilUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("LastSuccessfulAuthUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("LastWrongAttemptUtc")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.ToTable("AuthAttemptStates", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.GasPriceLookupEntity", b =>
+                {
+                    b.Property<int>("GasPriceLookupId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DataSource")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly>("EiaPeriodDate")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly>("PriceDate")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("PricePerGallon")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("RetrievedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("GasPriceLookupId");
+
+                    b.HasIndex("PriceDate")
+                        .IsUnique();
+
+                    b.ToTable("GasPriceLookups", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime?>("CompletedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("EtaMinutesRounded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FailedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("ImportedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("OverrideAllDuplicates")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<int>("ProcessedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<long>("RiderId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("SkippedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateTime?>("StartedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("TotalRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RiderId", "CreatedAtUtc");
+
+                    b.ToTable("ImportJobs", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportJobs_FailedRows_NonNegative", "\"FailedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ImportedRows_NonNegative", "\"ImportedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_Lte_TotalRows", "\"ProcessedRows\" <= \"TotalRows\"");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_NonNegative", "\"ProcessedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_SkippedRows_NonNegative", "\"SkippedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_TotalRows_NonNegative", "\"TotalRows\" >= 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long?>("CreatedRideId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DuplicateResolution")
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DuplicateStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ExistingRideIdsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("ImportJobId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("Miles")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Notes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ProcessingStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly?>("RideDateLocal")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RideMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("RowNumber")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("TagsRaw")
+                        .HasMaxLength(512)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationErrorsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ImportJobId", "RowNumber")
+                        .IsUnique();
+
+                    b.ToTable("ImportRows", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportRows_Miles_Range", "\"Miles\" IS NULL OR (CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200)");
+
+                            t.HasCheckConstraint("CK_ImportRows_RideMinutes_Positive", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+
+                            t.HasCheckConstraint("CK_ImportRows_RowNumber_Positive", "\"RowNumber\" > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CloudCoverPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("GasPricePerGallon")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("Miles")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PrecipitationType")
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RelativeHumidityPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("RideDateTimeLocal")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RideMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("RiderId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("SnapshotAverageCarMpg")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotMileageRateCents")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotOilChangePrice")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotYearlyGoalMiles")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("Version")
+                        .IsConcurrencyToken()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(1);
+
+                    b.Property<bool>("WeatherUserOverridden")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<int?>("WindDirectionDeg")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("WindSpeedMph")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RiderId", "CreatedAtUtc")
+                        .IsDescending(false, true)
+                        .HasDatabaseName("IX_Rides_RiderId_CreatedAtUtc_Desc");
+
+                    b.ToTable("Rides", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_Rides_Miles_GreaterThanZero", "CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200");
+
+                            t.HasCheckConstraint("CK_Rides_RideMinutes_GreaterThanZero", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotAverageCarMpg_Positive", "\"SnapshotAverageCarMpg\" IS NULL OR CAST(\"SnapshotAverageCarMpg\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotMileageRateCents_Positive", "\"SnapshotMileageRateCents\" IS NULL OR CAST(\"SnapshotMileageRateCents\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotOilChangePrice_Positive", "\"SnapshotOilChangePrice\" IS NULL OR CAST(\"SnapshotOilChangePrice\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotYearlyGoalMiles_Positive", "\"SnapshotYearlyGoalMiles\" IS NULL OR CAST(\"SnapshotYearlyGoalMiles\" AS REAL) > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.UserSettingsEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("AverageCarMpg")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("DashboardGallonsAvoidedEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<bool>("DashboardGoalProgressEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<decimal?>("Latitude")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LocationLabel")
+                        .HasMaxLength(200)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Longitude")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("MileageRateCents")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("OilChangePrice")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("UpdatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("YearlyGoalMiles")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.ToTable("UserSettings", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_UserSettings_AverageCarMpg_Positive", "\"AverageCarMpg\" IS NULL OR CAST(\"AverageCarMpg\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_Latitude_Range", "\"Latitude\" IS NULL OR (CAST(\"Latitude\" AS REAL) >= -90 AND CAST(\"Latitude\" AS REAL) <= 90)");
+
+                            t.HasCheckConstraint("CK_UserSettings_Longitude_Range", "\"Longitude\" IS NULL OR (CAST(\"Longitude\" AS REAL) >= -180 AND CAST(\"Longitude\" AS REAL) <= 180)");
+
+                            t.HasCheckConstraint("CK_UserSettings_MileageRateCents_Positive", "\"MileageRateCents\" IS NULL OR CAST(\"MileageRateCents\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_OilChangePrice_Positive", "\"OilChangePrice\" IS NULL OR CAST(\"OilChangePrice\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_YearlyGoalMiles_Positive", "\"YearlyGoalMiles\" IS NULL OR CAST(\"YearlyGoalMiles\" AS REAL) > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.WeatherLookupEntity", b =>
+                {
+                    b.Property<int>("WeatherLookupId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CloudCoverPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DataSource")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("LatitudeRounded")
+                        .HasPrecision(8, 2)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("LongitudeRounded")
+                        .HasPrecision(8, 2)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("LookupHourUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PrecipitationType")
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RelativeHumidityPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("RetrievedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("WindDirectionDeg")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("WindSpeedMph")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("WeatherLookupId");
+
+                    b.HasIndex("LookupHourUtc", "LatitudeRounded", "LongitudeRounded")
+                        .IsUnique();
+
+                    b.ToTable("WeatherLookups", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.OutboxEventEntity", b =>
+                {
+                    b.Property<long>("OutboxEventId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("AggregateId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AggregateType")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EventPayloadJson")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EventType")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("NextAttemptUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("OccurredAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("PublishedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("RetryCount")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.HasKey("OutboxEventId");
+
+                    b.HasIndex("AggregateType", "AggregateId");
+
+                    b.HasIndex("PublishedAtUtc", "NextAttemptUtc");
+
+                    b.ToTable("OutboxEvents", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", b =>
+                {
+                    b.Property<long>("UserCredentialId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("CredentialVersion")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("HashAlgorithm")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("IterationCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<byte[]>("PinHash")
+                        .IsRequired()
+                        .HasColumnType("BLOB");
+
+                    b.Property<byte[]>("PinSalt")
+                        .IsRequired()
+                        .HasColumnType("BLOB");
+
+                    b.Property<DateTime>("UpdatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("UserCredentialId");
+
+                    b.HasIndex("UserId")
+                        .IsUnique();
+
+                    b.ToTable("UserCredentials", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DisplayName")
+                        .IsRequired()
+                        .HasMaxLength(120)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsActive")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(true);
+
+                    b.Property<string>("NormalizedName")
+                        .IsRequired()
+                        .HasMaxLength(120)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.HasIndex("NormalizedName")
+                        .IsUnique();
+
+                    b.ToTable("Users", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", "User")
+                        .WithOne("AuthAttemptState")
+                        .HasForeignKey("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", "UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RiderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", "ImportJob")
+                        .WithMany("Rows")
+                        .HasForeignKey("ImportJobId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ImportJob");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RiderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.UserSettingsEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", "User")
+                        .WithOne("Credential")
+                        .HasForeignKey("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", "UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Navigation("Rows");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserEntity", b =>
+                {
+                    b.Navigation("AuthAttemptState");
+
+                    b.Navigation("Credential");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.cs
new file mode 100644
index 0000000..4d8e4f1
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260408185627_AddCsvRideImport.cs
@@ -0,0 +1,110 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace BikeTracking.Api.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddCsvRideImport : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "ImportJobs",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    RiderId = table.Column<long>(type: "INTEGER", nullable: false),
+                    FileName = table.Column<string>(type: "TEXT", maxLength: 255, nullable: false),
+                    TotalRows = table.Column<int>(type: "INTEGER", nullable: false, defaultValue: 0),
+                    ProcessedRows = table.Column<int>(type: "INTEGER", nullable: false, defaultValue: 0),
+                    ImportedRows = table.Column<int>(type: "INTEGER", nullable: false, defaultValue: 0),
+                    SkippedRows = table.Column<int>(type: "INTEGER", nullable: false, defaultValue: 0),
+                    FailedRows = table.Column<int>(type: "INTEGER", nullable: false, defaultValue: 0),
+                    Status = table.Column<string>(type: "TEXT", maxLength: 50, nullable: false),
+                    OverrideAllDuplicates = table.Column<bool>(type: "INTEGER", nullable: false, defaultValue: false),
+                    EtaMinutesRounded = table.Column<int>(type: "INTEGER", nullable: true),
+                    CreatedAtUtc = table.Column<DateTime>(type: "TEXT", nullable: false),
+                    StartedAtUtc = table.Column<DateTime>(type: "TEXT", nullable: true),
+                    CompletedAtUtc = table.Column<DateTime>(type: "TEXT", nullable: true),
+                    LastError = table.Column<string>(type: "TEXT", maxLength: 2048, nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ImportJobs", x => x.Id);
+                    table.CheckConstraint("CK_ImportJobs_FailedRows_NonNegative", "\"FailedRows\" >= 0");
+                    table.CheckConstraint("CK_ImportJobs_ImportedRows_NonNegative", "\"ImportedRows\" >= 0");
+                    table.CheckConstraint("CK_ImportJobs_ProcessedRows_Lte_TotalRows", "\"ProcessedRows\" <= \"TotalRows\"");
+                    table.CheckConstraint("CK_ImportJobs_ProcessedRows_NonNegative", "\"ProcessedRows\" >= 0");
+                    table.CheckConstraint("CK_ImportJobs_SkippedRows_NonNegative", "\"SkippedRows\" >= 0");
+                    table.CheckConstraint("CK_ImportJobs_TotalRows_NonNegative", "\"TotalRows\" >= 0");
+                    table.ForeignKey(
+                        name: "FK_ImportJobs_Users_RiderId",
+                        column: x => x.RiderId,
+                        principalTable: "Users",
+                        principalColumn: "UserId",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "ImportRows",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    ImportJobId = table.Column<long>(type: "INTEGER", nullable: false),
+                    RowNumber = table.Column<int>(type: "INTEGER", nullable: false),
+                    RideDateLocal = table.Column<DateOnly>(type: "TEXT", nullable: true),
+                    Miles = table.Column<decimal>(type: "TEXT", precision: 10, scale: 4, nullable: true),
+                    RideMinutes = table.Column<int>(type: "INTEGER", nullable: true),
+                    Temperature = table.Column<decimal>(type: "TEXT", precision: 10, scale: 4, nullable: true),
+                    TagsRaw = table.Column<string>(type: "TEXT", maxLength: 512, nullable: true),
+                    Notes = table.Column<string>(type: "TEXT", maxLength: 2000, nullable: true),
+                    ValidationStatus = table.Column<string>(type: "TEXT", maxLength: 30, nullable: false),
+                    ValidationErrorsJson = table.Column<string>(type: "TEXT", nullable: true),
+                    DuplicateStatus = table.Column<string>(type: "TEXT", maxLength: 30, nullable: false),
+                    DuplicateResolution = table.Column<string>(type: "TEXT", maxLength: 30, nullable: true),
+                    ProcessingStatus = table.Column<string>(type: "TEXT", maxLength: 30, nullable: false),
+                    ExistingRideIdsJson = table.Column<string>(type: "TEXT", nullable: true),
+                    CreatedRideId = table.Column<long>(type: "INTEGER", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_ImportRows", x => x.Id);
+                    table.CheckConstraint("CK_ImportRows_Miles_Range", "\"Miles\" IS NULL OR (CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200)");
+                    table.CheckConstraint("CK_ImportRows_RideMinutes_Positive", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+                    table.CheckConstraint("CK_ImportRows_RowNumber_Positive", "\"RowNumber\" > 0");
+                    table.ForeignKey(
+                        name: "FK_ImportRows_ImportJobs_ImportJobId",
+                        column: x => x.ImportJobId,
+                        principalTable: "ImportJobs",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ImportJobs_RiderId_CreatedAtUtc",
+                table: "ImportJobs",
+                columns: new[] { "RiderId", "CreatedAtUtc" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ImportRows_ImportJobId_RowNumber",
+                table: "ImportRows",
+                columns: new[] { "ImportJobId", "RowNumber" },
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "ImportRows");
+
+            migrationBuilder.DropTable(
+                name: "ImportJobs");
+        }
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
index 8b24e29..37349be 100644
--- a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
@@ -73,6 +73,168 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.ToTable("GasPriceLookups", (string)null);
                 });
 
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime?>("CompletedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("EtaMinutesRounded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FailedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("ImportedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("OverrideAllDuplicates")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<int>("ProcessedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<long>("RiderId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("SkippedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateTime?>("StartedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("TotalRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RiderId", "CreatedAtUtc");
+
+                    b.ToTable("ImportJobs", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportJobs_FailedRows_NonNegative", "\"FailedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ImportedRows_NonNegative", "\"ImportedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_Lte_TotalRows", "\"ProcessedRows\" <= \"TotalRows\"");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_NonNegative", "\"ProcessedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_SkippedRows_NonNegative", "\"SkippedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_TotalRows_NonNegative", "\"TotalRows\" >= 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long?>("CreatedRideId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DuplicateResolution")
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DuplicateStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ExistingRideIdsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("ImportJobId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("Miles")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Notes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ProcessingStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly?>("RideDateLocal")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RideMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("RowNumber")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("TagsRaw")
+                        .HasMaxLength(512)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationErrorsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ImportJobId", "RowNumber")
+                        .IsUnique();
+
+                    b.ToTable("ImportRows", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportRows_Miles_Range", "\"Miles\" IS NULL OR (CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200)");
+
+                            t.HasCheckConstraint("CK_ImportRows_RideMinutes_Positive", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+
+                            t.HasCheckConstraint("CK_ImportRows_RowNumber_Positive", "\"RowNumber\" > 0");
+                        });
+                });
+
             modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
                 {
                     b.Property<int>("Id")
@@ -416,6 +578,26 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.Navigation("User");
                 });
 
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RiderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", "ImportJob")
+                        .WithMany("Rows")
+                        .HasForeignKey("ImportJobId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ImportJob");
+                });
+
             modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
                 {
                     b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
@@ -445,6 +627,11 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.Navigation("User");
                 });
 
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Navigation("Rows");
+                });
+
             modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserEntity", b =>
                 {
                     b.Navigation("AuthAttemptState");
diff --git a/src/BikeTracking.Api/Program.cs b/src/BikeTracking.Api/Program.cs
index e2416df..f0f8331 100644
--- a/src/BikeTracking.Api/Program.cs
+++ b/src/BikeTracking.Api/Program.cs
@@ -1,5 +1,7 @@
 using BikeTracking.Api.Application.Dashboard;
 using BikeTracking.Api.Application.Events;
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Application.Notifications;
 using BikeTracking.Api.Application.Rides;
 using BikeTracking.Api.Application.Users;
 using BikeTracking.Api.Endpoints;
@@ -51,6 +53,9 @@
 builder.Services.AddScoped<GetRideHistoryService>();
 builder.Services.AddScoped<EditRideService>();
 builder.Services.AddScoped<DeleteRideService>();
+builder.Services.AddScoped<ICsvRideImportService, CsvRideImportService>();
+builder.Services.AddScoped<IDuplicateResolutionService, DuplicateResolutionService>();
+builder.Services.AddScoped<IImportProgressNotifier, ImportProgressNotifier>();
 builder.Services.AddScoped<IGasPriceLookupService, EiaGasPriceLookupService>();
 builder.Services.AddScoped<IWeatherLookupService, OpenMeteoWeatherLookupService>();
 
@@ -148,6 +153,7 @@
 app.MapDashboardEndpoints();
 app.MapUsersEndpoints();
 app.MapRidesEndpoints();
+app.MapImportEndpoints();
 app.MapDefaultEndpoints();
 
 app.Run();
diff --git a/src/BikeTracking.Frontend/src/App.tsx b/src/BikeTracking.Frontend/src/App.tsx
index 9389c21..09e7531 100644
--- a/src/BikeTracking.Frontend/src/App.tsx
+++ b/src/BikeTracking.Frontend/src/App.tsx
@@ -8,6 +8,7 @@ import { MilesShellPage } from './pages/miles/miles-shell-page'
 import { RecordRidePage } from './pages/RecordRidePage'
 import { HistoryPage } from './pages/HistoryPage'
 import { SettingsPage } from './pages/settings/SettingsPage'
+import { ImportRidesPage } from './pages/import-rides/ImportRidesPage'
 
 function App() {
   return (
@@ -22,6 +23,7 @@ function App() {
             <Route path="/miles" element={<MilesShellPage />} />
             <Route path="/rides/history" element={<HistoryPage />} />
             <Route path="/rides/record" element={<RecordRidePage />} />
+            <Route path="/rides/import" element={<ImportRidesPage />} />
             <Route path="/settings" element={<SettingsPage />} />
           </Route>
         </Routes>
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.css b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.css
new file mode 100644
index 0000000..b0d7113
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.css
@@ -0,0 +1,81 @@
+.duplicate-resolution-backdrop {
+  position: fixed;
+  inset: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgb(17 24 39 / 45%);
+  padding: 1rem;
+}
+
+.duplicate-resolution-dialog {
+  width: min(42rem, 100%);
+  max-height: min(85vh, 48rem);
+  overflow: auto;
+  border-radius: 0.9rem;
+  background: #fffdf8;
+  border: 1px solid #e7d7bd;
+  box-shadow: 0 18px 48px rgb(35 31 24 / 24%);
+  padding: 1.25rem;
+}
+
+.duplicate-resolution-dialog h2,
+.duplicate-resolution-dialog h3 {
+  margin-top: 0;
+}
+
+.duplicate-resolution-summary {
+  color: #5b4631;
+}
+
+.duplicate-resolution-override {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+  margin: 1rem 0;
+  font-weight: 600;
+}
+
+.duplicate-resolution-list {
+  display: grid;
+  gap: 1rem;
+}
+
+.duplicate-resolution-row {
+  border: 1px solid #eadfcd;
+  border-radius: 0.75rem;
+  background: #fff;
+  padding: 1rem;
+}
+
+.duplicate-resolution-row p,
+.duplicate-resolution-row ul,
+.duplicate-resolution-row fieldset {
+  margin: 0.75rem 0 0;
+}
+
+.duplicate-resolution-row fieldset {
+  border: none;
+  padding: 0;
+  display: grid;
+  gap: 0.5rem;
+}
+
+.duplicate-resolution-row legend {
+  padding: 0;
+  font-weight: 600;
+  margin-bottom: 0.5rem;
+}
+
+.duplicate-resolution-row label {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+}
+
+.duplicate-resolution-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: 0.75rem;
+  margin-top: 1rem;
+}
\ No newline at end of file
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.test.tsx b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.test.tsx
new file mode 100644
index 0000000..b28422f
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.test.tsx
@@ -0,0 +1,172 @@
+import userEvent from '@testing-library/user-event'
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import { DuplicateResolutionDialog } from './DuplicateResolutionDialog'
+
+const duplicateRows = [
+  {
+    rowNumber: 1,
+    date: '2026-04-01',
+    miles: 12.5,
+    rideMinutes: 45,
+    temperature: 60,
+    tags: 'commute',
+    notes: 'incoming ride',
+    isValid: true,
+    errors: [],
+    duplicateMatches: [
+      {
+        existingRideId: 9,
+        existingRideDate: '2026-04-01',
+        existingMiles: 12.5,
+      },
+    ],
+  },
+  {
+    rowNumber: 2,
+    date: '2026-04-02',
+    miles: 9.25,
+    rideMinutes: 30,
+    temperature: null,
+    tags: 'errand',
+    notes: 'another incoming ride',
+    isValid: true,
+    errors: [],
+    duplicateMatches: [
+      {
+        existingRideId: 10,
+        existingRideDate: '2026-04-02',
+        existingMiles: 9.25,
+      },
+    ],
+  },
+] as const
+
+describe('DuplicateResolutionDialog', () => {
+  it('does not render when closed', () => {
+    render(
+      <DuplicateResolutionDialog
+        isOpen={false}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={false}
+        resolutions={[]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={vi.fn()}
+        onOverrideAllDuplicatesChange={vi.fn()}
+        onResolutionChange={vi.fn()}
+      />
+    )
+
+    expect(screen.queryByRole('dialog', { name: /duplicate resolution/i })).not.toBeInTheDocument()
+  })
+
+  it('renders duplicate rows and enables confirmation once every row has a resolution', async () => {
+    const user = userEvent.setup()
+    const onResolutionChange = vi.fn()
+
+    const { rerender } = render(
+      <DuplicateResolutionDialog
+        isOpen={true}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={false}
+        resolutions={[]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={vi.fn()}
+        onOverrideAllDuplicatesChange={vi.fn()}
+        onResolutionChange={onResolutionChange}
+      />
+    )
+
+    expect(screen.getByRole('heading', { name: /row 1/i })).toBeInTheDocument()
+    expect(screen.getByText(/existing ride #9/i)).toBeInTheDocument()
+
+    const confirmButton = screen.getByRole('button', { name: /start import/i })
+    expect(confirmButton).toBeDisabled()
+
+    await user.click(screen.getByLabelText(/row 1 keep existing/i))
+    expect(onResolutionChange).toHaveBeenCalledWith(1, 'keep-existing')
+
+    rerender(
+      <DuplicateResolutionDialog
+        isOpen={true}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={false}
+        resolutions={[{ rowNumber: 1, action: 'keep-existing' }]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={vi.fn()}
+        onOverrideAllDuplicatesChange={vi.fn()}
+        onResolutionChange={onResolutionChange}
+      />
+    )
+
+    expect(confirmButton).toBeDisabled()
+
+    await user.click(screen.getByLabelText(/row 2 replace with import/i))
+    expect(onResolutionChange).toHaveBeenCalledWith(2, 'replace-with-import')
+
+    rerender(
+      <DuplicateResolutionDialog
+        isOpen={true}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={false}
+        resolutions={[
+          { rowNumber: 1, action: 'keep-existing' },
+          { rowNumber: 2, action: 'replace-with-import' },
+        ]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={vi.fn()}
+        onOverrideAllDuplicatesChange={vi.fn()}
+        onResolutionChange={onResolutionChange}
+      />
+    )
+
+    expect(confirmButton).toBeEnabled()
+  })
+
+  it('allows override-all to enable confirmation without per-row selections', async () => {
+    const user = userEvent.setup()
+    const onOverrideAllDuplicatesChange = vi.fn()
+    const onConfirm = vi.fn()
+
+    const { rerender } = render(
+      <DuplicateResolutionDialog
+        isOpen={true}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={false}
+        resolutions={[]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={onConfirm}
+        onOverrideAllDuplicatesChange={onOverrideAllDuplicatesChange}
+        onResolutionChange={vi.fn()}
+      />
+    )
+
+    await user.click(screen.getByLabelText(/override all duplicates/i))
+    expect(onOverrideAllDuplicatesChange).toHaveBeenCalledWith(true)
+
+    rerender(
+      <DuplicateResolutionDialog
+        isOpen={true}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={true}
+        resolutions={[]}
+        isSubmitting={false}
+        onClose={vi.fn()}
+        onConfirm={onConfirm}
+        onOverrideAllDuplicatesChange={onOverrideAllDuplicatesChange}
+        onResolutionChange={vi.fn()}
+      />
+    )
+
+    const confirmButton = screen.getByRole('button', { name: /start import/i })
+    expect(confirmButton).toBeEnabled()
+
+    await user.click(confirmButton)
+    expect(onConfirm).toHaveBeenCalledTimes(1)
+  })
+})
\ No newline at end of file
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.tsx b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.tsx
new file mode 100644
index 0000000..e42b835
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/components/import-rides/DuplicateResolutionDialog.tsx
@@ -0,0 +1,135 @@
+import type { ImportDuplicateResolution, ImportPreviewRow } from '../../services/import-api'
+import './DuplicateResolutionDialog.css'
+
+export interface DuplicateResolutionDialogProps {
+  isOpen: boolean
+  duplicateRows: readonly ImportPreviewRow[]
+  overrideAllDuplicates: boolean
+  resolutions: readonly ImportDuplicateResolution[]
+  isSubmitting: boolean
+  onClose: () => void
+  onConfirm: () => void
+  onOverrideAllDuplicatesChange: (value: boolean) => void
+  onResolutionChange: (
+    rowNumber: number,
+    action: ImportDuplicateResolution['action']
+  ) => void
+}
+
+function getResolution(
+  resolutions: readonly ImportDuplicateResolution[],
+  rowNumber: number
+): ImportDuplicateResolution['action'] | null {
+  const match = resolutions.find((resolution) => resolution.rowNumber === rowNumber)
+  return match?.action ?? null
+}
+
+function formatMiles(value: number | null | undefined): string {
+  if (typeof value !== 'number') {
+    return 'Unknown miles'
+  }
+
+  return `${value.toFixed(1)} mi`
+}
+
+export function DuplicateResolutionDialog({
+  isOpen,
+  duplicateRows,
+  overrideAllDuplicates,
+  resolutions,
+  isSubmitting,
+  onClose,
+  onConfirm,
+  onOverrideAllDuplicatesChange,
+  onResolutionChange,
+}: DuplicateResolutionDialogProps) {
+  if (!isOpen) {
+    return null
+  }
+
+  const duplicateCount = duplicateRows.length
+  const hasAllResolutions = duplicateRows.every(
+    (row) => getResolution(resolutions, row.rowNumber) !== null
+  )
+  const canConfirm = overrideAllDuplicates || hasAllResolutions
+
+  return (
+    <div className="duplicate-resolution-backdrop" role="presentation">
+      <section
+        aria-label="Duplicate resolution"
+        aria-modal="true"
+        className="duplicate-resolution-dialog"
+        role="dialog"
+      >
+        <h2>Resolve duplicates</h2>
+        <p className="duplicate-resolution-summary">
+          {duplicateCount} {duplicateCount === 1 ? 'duplicate row requires' : 'duplicate rows require'} a
+          decision before import can start.
+        </p>
+
+        <label className="duplicate-resolution-override">
+          <input
+            type="checkbox"
+            checked={overrideAllDuplicates}
+            onChange={(event) => onOverrideAllDuplicatesChange(event.target.checked)}
+          />
+          Override all duplicates
+        </label>
+
+        <div className="duplicate-resolution-list">
+          {duplicateRows.map((row) => {
+            const selectedAction = getResolution(resolutions, row.rowNumber)
+
+            return (
+              <section key={row.rowNumber} className="duplicate-resolution-row">
+                <h3>Row {row.rowNumber}</h3>
+                <p>
+                  Incoming ride: {row.date ?? 'Unknown date'} • {formatMiles(row.miles)}
+                </p>
+                <ul>
+                  {row.duplicateMatches.map((match) => (
+                    <li key={match.existingRideId}>
+                      Existing ride #{match.existingRideId}: {match.existingRideDate} •{' '}
+                      {formatMiles(match.existingMiles)}
+                    </li>
+                  ))}
+                </ul>
+
+                <fieldset disabled={overrideAllDuplicates}>
+                  <legend>Choose how to resolve row {row.rowNumber}</legend>
+                  <label>
+                    <input
+                      type="radio"
+                      name={`duplicate-row-${row.rowNumber}`}
+                      checked={selectedAction === 'keep-existing'}
+                      onChange={() => onResolutionChange(row.rowNumber, 'keep-existing')}
+                    />
+                    Row {row.rowNumber} keep existing
+                  </label>
+                  <label>
+                    <input
+                      type="radio"
+                      name={`duplicate-row-${row.rowNumber}`}
+                      checked={selectedAction === 'replace-with-import'}
+                      onChange={() => onResolutionChange(row.rowNumber, 'replace-with-import')}
+                    />
+                    Row {row.rowNumber} replace with import
+                  </label>
+                </fieldset>
+              </section>
+            )
+          })}
+        </div>
+
+        <div className="duplicate-resolution-actions">
+          <button type="button" onClick={onClose} disabled={isSubmitting}>
+            Cancel
+          </button>
+          <button type="button" onClick={onConfirm} disabled={!canConfirm || isSubmitting}>
+            {isSubmitting ? 'Starting...' : 'Start Import'}
+          </button>
+        </div>
+      </section>
+    </div>
+  )
+}
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
new file mode 100644
index 0000000..b0150ce
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
@@ -0,0 +1,52 @@
+import userEvent from '@testing-library/user-event'
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import { ImportProgressPanel } from './ImportProgressPanel'
+
+describe('ImportProgressPanel', () => {
+  it('renders processing progress with estimating text and cancel action', () => {
+    render(
+      <ImportProgressPanel
+        status="processing"
+        percentComplete={25}
+        etaMinutesRounded={null}
+        importedRows={3}
+        skippedRows={1}
+        failedRows={0}
+        isCancelling={false}
+        onCancel={vi.fn()}
+      />
+    )
+
+    expect(screen.getByText(/status: processing/i)).toBeInTheDocument()
+    expect(screen.getByText(/complete: 25%/i)).toBeInTheDocument()
+    expect(screen.getByText(/eta: estimating/i)).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: /cancel import/i })).toBeInTheDocument()
+  })
+
+  it('renders terminal summary and hides cancel action after cancellation', async () => {
+    const user = userEvent.setup()
+    const onCancel = vi.fn()
+
+    render(
+      <ImportProgressPanel
+        status="cancelled"
+        percentComplete={40}
+        etaMinutesRounded={null}
+        importedRows={4}
+        skippedRows={2}
+        failedRows={1}
+        isCancelling={false}
+        onCancel={onCancel}
+      />
+    )
+
+    expect(screen.getByText(/imported: 4/i)).toBeInTheDocument()
+    expect(screen.getByText(/skipped: 2/i)).toBeInTheDocument()
+    expect(screen.getByText(/failed: 1/i)).toBeInTheDocument()
+    expect(screen.queryByRole('button', { name: /cancel import/i })).not.toBeInTheDocument()
+
+    await user.keyboard('{Tab}')
+    expect(onCancel).not.toHaveBeenCalled()
+  })
+})
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
new file mode 100644
index 0000000..c502825
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
@@ -0,0 +1,45 @@
+interface ImportProgressPanelProps {
+  status: string
+  percentComplete: number | null
+  etaMinutesRounded: number | null
+  importedRows: number
+  skippedRows: number
+  failedRows: number
+  isCancelling: boolean
+  onCancel: () => void
+}
+
+function isTerminalStatus(status: string): boolean {
+  return status === 'completed' || status === 'cancelled' || status === 'failed'
+}
+
+export function ImportProgressPanel({
+  status,
+  percentComplete,
+  etaMinutesRounded,
+  importedRows,
+  skippedRows,
+  failedRows,
+  isCancelling,
+  onCancel,
+}: ImportProgressPanelProps) {
+  const etaText = etaMinutesRounded === null ? 'Estimating...' : `~${etaMinutesRounded} minutes remaining`
+  const isTerminal = isTerminalStatus(status)
+
+  return (
+    <section aria-label="Import progress">
+      <h2>Import Progress</h2>
+      <p>Status: {status}</p>
+      <p>Complete: {percentComplete ?? 0}%</p>
+      <p>ETA: {etaText}</p>
+      <p>Imported: {importedRows}</p>
+      <p>Skipped: {skippedRows}</p>
+      <p>Failed: {failedRows}</p>
+      {!isTerminal ? (
+        <button type="button" onClick={onCancel} disabled={isCancelling}>
+          {isCancelling ? 'Cancelling...' : 'Cancel Import'}
+        </button>
+      ) : null}
+    </section>
+  )
+}
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
new file mode 100644
index 0000000..2a57552
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
@@ -0,0 +1,95 @@
+.import-rides-page {
+  display: flex;
+  justify-content: center;
+  padding: 1.5rem;
+}
+
+.import-rides-card {
+  width: min(52rem, 100%);
+  border-radius: 0.75rem;
+  border: 1px solid #d5dbe5;
+  background: #ffffff;
+  padding: 1.5rem;
+  box-shadow: 0 8px 24px rgb(14 30 37 / 10%);
+}
+
+.import-rides-card h1 {
+  margin: 0 0 0.5rem;
+}
+
+.import-rides-description {
+  margin: 0 0 1rem;
+  color: #2f3f56;
+}
+
+.import-rides-file-label {
+  display: block;
+  margin-bottom: 0.35rem;
+  font-weight: 600;
+}
+
+.import-rides-file-input {
+  width: 100%;
+}
+
+.import-rides-selected-file {
+  margin-top: 0.75rem;
+  color: #1a2738;
+}
+
+.import-rides-error {
+  color: #b42318;
+  margin: 0.5rem 0 0;
+}
+
+.import-rides-actions {
+  margin-top: 0.75rem;
+}
+
+.import-rides-actions button {
+  border: none;
+  border-radius: 0.5rem;
+  background: #2f6fdd;
+  color: #fff;
+  padding: 0.6rem 1rem;
+  font-weight: 600;
+  cursor: pointer;
+}
+
+.import-rides-actions button:disabled {
+  opacity: 0.7;
+  cursor: default;
+}
+
+.import-rides-preview {
+  margin-top: 1rem;
+  border-top: 1px solid #d5dbe5;
+  padding-top: 1rem;
+}
+
+.import-rides-preview h2 {
+  margin: 0 0 0.5rem;
+}
+
+.import-rides-duplicates {
+  margin: 0.5rem 0 0;
+  color: #6c4b1f;
+  font-weight: 600;
+}
+
+.import-rides-preview ul {
+  margin: 0.5rem 0 0;
+  padding-left: 1.25rem;
+}
+
+.import-rides-status {
+  margin-top: 0.75rem;
+  color: #17324d;
+  font-weight: 600;
+}
+
+.import-rides-placeholder {
+  margin-top: 1rem;
+  color: #465872;
+  font-style: italic;
+}
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
new file mode 100644
index 0000000..05315f5
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
@@ -0,0 +1,512 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { fireEvent, render, screen, waitFor, within } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { BrowserRouter } from 'react-router-dom'
+import { ImportRidesPage } from './ImportRidesPage'
+import * as importApi from '../../services/import-api'
+
+vi.mock('../../services/import-api', () => ({
+  previewImportCsv: vi.fn(),
+  startImportCsv: vi.fn(),
+  getImportStatus: vi.fn(),
+  cancelImport: vi.fn(),
+}))
+
+const mockPreviewImportCsv = vi.mocked(importApi.previewImportCsv)
+const mockStartImportCsv = vi.mocked(importApi.startImportCsv)
+const mockGetImportStatus = vi.mocked(importApi.getImportStatus)
+const mockCancelImport = vi.mocked(importApi.cancelImport)
+
+describe('ImportRidesPage', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    sessionStorage.clear()
+  })
+
+  it('renders preview summary after successful upload preview', async () => {
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 101,
+        totalRows: 2,
+        validRows: 1,
+        invalidRows: 1,
+        duplicateRows: 0,
+        requiresDuplicateResolution: false,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+          {
+            rowNumber: 2,
+            date: '2026-04-02',
+            miles: null,
+            rideMinutes: 45,
+            temperature: 62,
+            tags: 'commute',
+            notes: 'bad row',
+            isValid: false,
+            errors: [
+              {
+                rowNumber: 2,
+                code: 'INVALID_MILES',
+                message: 'Miles must be greater than 0 and less than or equal to 200.',
+                field: 'Miles',
+              },
+            ],
+            duplicateMatches: [],
+          },
+        ],
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+
+    await waitFor(() => {
+      expect(screen.getByText(/total rows: 2/i)).toBeInTheDocument()
+      expect(screen.getByText(/valid rows: 1/i)).toBeInTheDocument()
+      expect(screen.getByText(/invalid rows: 1/i)).toBeInTheDocument()
+      expect(screen.getByText(/miles: miles must be greater than 0/i)).toBeInTheDocument()
+    })
+  })
+
+  it('shows error when selected file is not csv', async () => {
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const nonCsvFile = new File(['not csv'], 'rides.pdf', { type: 'application/pdf' })
+
+    fireEvent.change(fileInput, { target: { files: [nonCsvFile] } })
+
+    expect(screen.getByRole('alert')).toHaveTextContent('Please upload a .csv file.')
+    expect(mockPreviewImportCsv).not.toHaveBeenCalled()
+  })
+
+  it('shows error when selected file exceeds 5 mb', async () => {
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const oversizedPayload = new Uint8Array(5 * 1024 * 1024 + 1)
+    const oversizedCsv = new File([oversizedPayload], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [oversizedCsv] } })
+
+    expect(screen.getByRole('alert')).toHaveTextContent('CSV file must be 5 MB or smaller.')
+    expect(mockPreviewImportCsv).not.toHaveBeenCalled()
+  })
+
+  it('opens duplicate resolution dialog before starting duplicate imports', async () => {
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 102,
+        totalRows: 1,
+        validRows: 1,
+        invalidRows: 0,
+        duplicateRows: 1,
+        requiresDuplicateResolution: true,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [
+              {
+                existingRideId: 7,
+                existingRideDate: '2026-04-01',
+                existingMiles: 12.5,
+              },
+            ],
+          },
+        ],
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+
+    await screen.findByText(/duplicate rows: 1/i)
+    fireEvent.click(screen.getByRole('button', { name: /start import/i }))
+
+    expect(screen.getByRole('dialog', { name: /duplicate resolution/i })).toBeInTheDocument()
+    expect(mockStartImportCsv).not.toHaveBeenCalled()
+  })
+
+  it('submits keep-existing duplicate resolutions from the dialog', async () => {
+    const user = userEvent.setup()
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 103,
+        totalRows: 1,
+        validRows: 1,
+        invalidRows: 0,
+        duplicateRows: 1,
+        requiresDuplicateResolution: true,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [
+              {
+                existingRideId: 7,
+                existingRideDate: '2026-04-01',
+                existingMiles: 12.5,
+              },
+            ],
+          },
+        ],
+      },
+    })
+    mockStartImportCsv.mockResolvedValue({
+      ok: true,
+      status: 202,
+      data: {
+        importJobId: 103,
+        status: 'processing',
+        startedAtUtc: '2026-04-08T10:00:00Z',
+      },
+    })
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 103,
+        status: 'processing',
+        totalRows: 1,
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        percentComplete: 0,
+        etaMinutesRounded: null,
+        createdAtUtc: '2026-04-08T09:59:00Z',
+        startedAtUtc: '2026-04-08T10:00:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+
+    await screen.findByText(/duplicate rows: 1/i)
+    await user.click(screen.getByRole('button', { name: /start import/i }))
+
+    const dialog = screen.getByRole('dialog', { name: /duplicate resolution/i })
+    await user.click(within(dialog).getByLabelText(/row 1 keep existing/i))
+    await user.click(within(dialog).getByRole('button', { name: /start import/i }))
+
+    await waitFor(() => {
+      expect(mockStartImportCsv).toHaveBeenCalledWith({
+        importJobId: 103,
+        overrideAllDuplicates: false,
+        resolutions: [{ rowNumber: 1, action: 'keep-existing' }],
+      })
+      expect(screen.getByText(/status: processing/i)).toBeInTheDocument()
+    })
+  })
+
+  it('submits override-all without per-row duplicate resolutions', async () => {
+    const user = userEvent.setup()
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 104,
+        totalRows: 1,
+        validRows: 1,
+        invalidRows: 0,
+        duplicateRows: 1,
+        requiresDuplicateResolution: true,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [
+              {
+                existingRideId: 7,
+                existingRideDate: '2026-04-01',
+                existingMiles: 12.5,
+              },
+            ],
+          },
+        ],
+      },
+    })
+    mockStartImportCsv.mockResolvedValue({
+      ok: true,
+      status: 202,
+      data: {
+        importJobId: 104,
+        status: 'processing',
+        startedAtUtc: '2026-04-08T10:05:00Z',
+      },
+    })
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 104,
+        status: 'processing',
+        totalRows: 1,
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        percentComplete: 0,
+        etaMinutesRounded: null,
+        createdAtUtc: '2026-04-08T10:04:00Z',
+        startedAtUtc: '2026-04-08T10:05:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+
+    await screen.findByText(/duplicate rows: 1/i)
+    await user.click(screen.getByRole('button', { name: /start import/i }))
+
+    const dialog = screen.getByRole('dialog', { name: /duplicate resolution/i })
+    await user.click(within(dialog).getByLabelText(/override all duplicates/i))
+    await user.click(within(dialog).getByRole('button', { name: /start import/i }))
+
+    await waitFor(() => {
+      expect(mockStartImportCsv).toHaveBeenCalledWith({
+        importJobId: 104,
+        overrideAllDuplicates: true,
+        resolutions: [],
+      })
+    })
+  })
+
+  it('renders the progress panel after import starts', async () => {
+    const user = userEvent.setup()
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 105,
+        totalRows: 2,
+        validRows: 2,
+        invalidRows: 0,
+        duplicateRows: 0,
+        requiresDuplicateResolution: false,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+          {
+            rowNumber: 2,
+            date: '2026-04-02',
+            miles: 10,
+            rideMinutes: 40,
+            temperature: 58,
+            tags: 'errand',
+            notes: 'afternoon',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+        ],
+      },
+    })
+    mockStartImportCsv.mockResolvedValue({
+      ok: true,
+      status: 202,
+      data: {
+        importJobId: 105,
+        status: 'processing',
+        startedAtUtc: '2026-04-08T10:10:00Z',
+      },
+    })
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 105,
+        status: 'processing',
+        totalRows: 2,
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        percentComplete: 0,
+        etaMinutesRounded: null,
+        createdAtUtc: '2026-04-08T10:09:00Z',
+        startedAtUtc: '2026-04-08T10:10:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+    await user.click(await screen.findByRole('button', { name: /start import/i }))
+
+    expect(await screen.findByRole('heading', { name: /import progress/i })).toBeInTheDocument()
+    expect(screen.getByText(/status: processing/i)).toBeInTheDocument()
+    expect(screen.getByText(/complete: 0%/i)).toBeInTheDocument()
+  })
+
+  it('cancels an in-progress import from the progress panel', async () => {
+    const user = userEvent.setup()
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 106,
+        status: 'processing',
+        totalRows: 20,
+        processedRows: 5,
+        importedRows: 4,
+        skippedRows: 1,
+        failedRows: 0,
+        percentComplete: 25,
+        etaMinutesRounded: 10,
+        createdAtUtc: '2026-04-08T10:14:00Z',
+        startedAtUtc: '2026-04-08T10:15:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+    mockCancelImport.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 106,
+        status: 'cancelled',
+        processedRows: 5,
+        importedRows: 4,
+        skippedRows: 1,
+        failedRows: 0,
+        cancelledAtUtc: '2026-04-08T10:16:00Z',
+      },
+    })
+    sessionStorage.setItem('bike_tracking_active_import_job_id', '106')
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    await screen.findByText(/status: processing/i)
+    await user.click(screen.getByRole('button', { name: /cancel import/i }))
+
+    await waitFor(() => {
+      expect(mockCancelImport).toHaveBeenCalledWith(106)
+      expect(screen.getByText(/status: cancelled/i)).toBeInTheDocument()
+      expect(screen.getByText(/imported: 4/i)).toBeInTheDocument()
+    })
+  })
+})
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
new file mode 100644
index 0000000..f44bc1d
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
@@ -0,0 +1,389 @@
+import { useEffect, useState } from 'react'
+import {
+  cancelImport,
+  getImportStatus,
+  type ImportDuplicateResolution,
+  previewImportCsv,
+  startImportCsv,
+  type ImportPreviewResponse,
+  type ImportPreviewRow,
+  type ImportStatusResponse,
+} from '../../services/import-api'
+import { DuplicateResolutionDialog } from '../../components/import-rides/DuplicateResolutionDialog'
+import { ImportProgressPanel } from '../../components/import-rides/ImportProgressPanel'
+import './ImportRidesPage.css'
+
+const MAX_UPLOAD_BYTES = 5 * 1024 * 1024
+const ACTIVE_IMPORT_JOB_KEY = 'bike_tracking_active_import_job_id'
+
+function isTerminalStatus(status: string): boolean {
+  return status === 'completed' || status === 'cancelled' || status === 'failed'
+}
+
+function readActiveImportJobId(): number | null {
+  const raw = sessionStorage.getItem(ACTIVE_IMPORT_JOB_KEY)
+  if (raw === null) {
+    return null
+  }
+
+  const parsed = Number.parseInt(raw, 10)
+  return Number.isNaN(parsed) || parsed <= 0 ? null : parsed
+}
+
+function persistActiveImportJobId(importJobId: number): void {
+  sessionStorage.setItem(ACTIVE_IMPORT_JOB_KEY, importJobId.toString())
+}
+
+function clearActiveImportJobId(): void {
+  sessionStorage.removeItem(ACTIVE_IMPORT_JOB_KEY)
+}
+
+export function ImportRidesPage() {
+  const [selectedFile, setSelectedFile] = useState<File | null>(null)
+  const [selectedFileName, setSelectedFileName] = useState<string>('')
+  const [isPreviewing, setIsPreviewing] = useState<boolean>(false)
+  const [isStarting, setIsStarting] = useState<boolean>(false)
+  const [isCancelling, setIsCancelling] = useState<boolean>(false)
+  const [errorMessage, setErrorMessage] = useState<string>('')
+  const [preview, setPreview] = useState<ImportPreviewResponse | null>(null)
+  const [status, setStatus] = useState<ImportStatusResponse | null>(null)
+  const [isDuplicateDialogOpen, setIsDuplicateDialogOpen] = useState<boolean>(false)
+  const [overrideAllDuplicates, setOverrideAllDuplicates] = useState<boolean>(false)
+  const [duplicateResolutions, setDuplicateResolutions] = useState<ImportDuplicateResolution[]>([])
+
+  const duplicateRows: ImportPreviewRow[] =
+    preview?.rows.filter((row) => row.duplicateMatches.length > 0) ?? []
+
+  useEffect(() => {
+    const importJobId = readActiveImportJobId()
+    if (importJobId === null) {
+      return
+    }
+
+    void loadStatus(importJobId)
+  }, [])
+
+  useEffect(() => {
+    if (status?.status !== 'processing') {
+      return
+    }
+
+    const intervalId = window.setInterval(() => {
+      void loadStatus(status.importJobId)
+    }, 2000)
+
+    return () => {
+      window.clearInterval(intervalId)
+    }
+  }, [status?.importJobId, status?.status])
+
+  function onSelectFile(event: React.ChangeEvent<HTMLInputElement>): void {
+    const file = event.target.files?.[0]
+
+    setErrorMessage('')
+    setPreview(null)
+    setStatus(null)
+    setIsDuplicateDialogOpen(false)
+    setOverrideAllDuplicates(false)
+    setDuplicateResolutions([])
+    clearActiveImportJobId()
+
+    if (!file) {
+      setSelectedFile(null)
+      setSelectedFileName('')
+      return
+    }
+
+    const hasCsvExtension = file.name.toLowerCase().endsWith('.csv')
+    if (!hasCsvExtension) {
+      setSelectedFile(null)
+      setSelectedFileName(file.name)
+      setErrorMessage('Please upload a .csv file.')
+      return
+    }
+
+    if (file.size > MAX_UPLOAD_BYTES) {
+      setSelectedFile(null)
+      setSelectedFileName(file.name)
+      setErrorMessage('CSV file must be 5 MB or smaller.')
+      return
+    }
+
+    setSelectedFile(file)
+    setSelectedFileName(file.name)
+  }
+
+  async function loadStatus(importJobId: number): Promise<void> {
+    const statusResponse = await getImportStatus(importJobId)
+    if (!statusResponse.ok || !statusResponse.data) {
+      setErrorMessage(statusResponse.error?.message ?? 'Unable to load import status.')
+      return
+    }
+
+    setStatus(statusResponse.data)
+    if (isTerminalStatus(statusResponse.data.status)) {
+      clearActiveImportJobId()
+    } else {
+      persistActiveImportJobId(statusResponse.data.importJobId)
+    }
+  }
+
+  async function toBase64(file: File): Promise<string> {
+    const bytes = new Uint8Array(await file.arrayBuffer())
+    let binary = ''
+    bytes.forEach((byte) => {
+      binary += String.fromCharCode(byte)
+    })
+
+    return window.btoa(binary)
+  }
+
+  async function onPreview(event: React.FormEvent<HTMLFormElement>): Promise<void> {
+    event.preventDefault()
+    setErrorMessage('')
+
+    if (!selectedFile) {
+      setErrorMessage('Select a CSV file before previewing import results.')
+      return
+    }
+
+    setIsPreviewing(true)
+    setStatus(null)
+    try {
+      const contentBase64 = await toBase64(selectedFile)
+      const response = await previewImportCsv({
+        fileName: selectedFile.name,
+        contentBase64,
+      })
+
+      if (response.ok && response.data) {
+        setPreview(response.data)
+        setIsDuplicateDialogOpen(false)
+        setOverrideAllDuplicates(false)
+        setDuplicateResolutions([])
+        return
+      }
+
+      setPreview(null)
+      setErrorMessage(response.error?.message ?? 'Unable to preview this CSV import.')
+    } catch {
+      setPreview(null)
+      setErrorMessage('Unable to preview this CSV import.')
+    } finally {
+      setIsPreviewing(false)
+    }
+  }
+
+  function onResolutionChange(
+    rowNumber: number,
+    action: ImportDuplicateResolution['action']
+  ): void {
+    setDuplicateResolutions((current) => {
+      const next = current.filter((resolution) => resolution.rowNumber !== rowNumber)
+      next.push({ rowNumber, action })
+      next.sort((left, right) => left.rowNumber - right.rowNumber)
+      return next
+    })
+  }
+
+  async function runStartImport(
+    importJobId: number,
+    overrideAll: boolean,
+    resolutions: ImportDuplicateResolution[]
+  ): Promise<void> {
+    setErrorMessage('')
+    setIsStarting(true)
+    try {
+      const startResponse = await startImportCsv({
+        importJobId,
+        overrideAllDuplicates: overrideAll,
+        resolutions,
+      })
+
+      if (!startResponse.ok || !startResponse.data) {
+        setErrorMessage(startResponse.error?.message ?? 'Unable to start import.')
+        return
+      }
+
+      setIsDuplicateDialogOpen(false)
+      persistActiveImportJobId(startResponse.data.importJobId)
+      await loadStatus(startResponse.data.importJobId)
+    } catch {
+      setErrorMessage('Unable to start import.')
+    } finally {
+      setIsStarting(false)
+    }
+  }
+
+  async function onStartImport(): Promise<void> {
+    if (!preview) {
+      return
+    }
+
+    if (preview.requiresDuplicateResolution && duplicateRows.length > 0) {
+      setIsDuplicateDialogOpen(true)
+      return
+    }
+
+    await runStartImport(preview.importJobId, false, [])
+  }
+
+  async function onConfirmDuplicateResolution(): Promise<void> {
+    if (!preview) {
+      return
+    }
+
+    await runStartImport(preview.importJobId, overrideAllDuplicates, duplicateResolutions)
+  }
+
+  async function onCancelImport(): Promise<void> {
+    if (status === null) {
+      return
+    }
+
+    setErrorMessage('')
+    setIsCancelling(true)
+    try {
+      const cancelResponse = await cancelImport(status.importJobId)
+      if (!cancelResponse.ok || !cancelResponse.data) {
+        setErrorMessage(cancelResponse.error?.message ?? 'Unable to cancel import.')
+        return
+      }
+
+      clearActiveImportJobId()
+      setStatus((current) => ({
+        importJobId: cancelResponse.data.importJobId,
+        status: cancelResponse.data.status,
+        totalRows: current?.totalRows ?? 0,
+        processedRows: cancelResponse.data.processedRows,
+        importedRows: cancelResponse.data.importedRows,
+        skippedRows: cancelResponse.data.skippedRows,
+        failedRows: cancelResponse.data.failedRows,
+        percentComplete: current?.percentComplete ?? null,
+        etaMinutesRounded: null,
+        createdAtUtc: current?.createdAtUtc ?? cancelResponse.data.cancelledAtUtc,
+        startedAtUtc: current?.startedAtUtc ?? null,
+        completedAtUtc: cancelResponse.data.cancelledAtUtc,
+        lastError: null,
+      }))
+    } catch {
+      setErrorMessage('Unable to cancel import.')
+    } finally {
+      setIsCancelling(false)
+    }
+  }
+
+  return (
+    <main className="import-rides-page">
+      <section className="import-rides-card">
+        <h1>Import Rides</h1>
+        <p className="import-rides-description">
+          Upload a CSV to preview row validation, duplicate matches, and import summary before
+          processing.
+        </p>
+
+        <form onSubmit={onPreview}>
+          <label className="import-rides-file-label" htmlFor="csv-upload-input">
+            Select CSV file
+          </label>
+          <input
+            id="csv-upload-input"
+            className="import-rides-file-input"
+            type="file"
+            accept=".csv,text/csv"
+            onChange={onSelectFile}
+          />
+
+          <p className="import-rides-selected-file" aria-live="polite">
+            {selectedFileName === '' ? 'No file selected.' : `Selected file: ${selectedFileName}`}
+          </p>
+
+          {errorMessage !== '' ? (
+            <p className="import-rides-error" role="alert">
+              {errorMessage}
+            </p>
+          ) : null}
+
+          <div className="import-rides-actions">
+            <button type="submit" disabled={isPreviewing}>
+              {isPreviewing ? 'Previewing...' : 'Preview Import'}
+            </button>
+          </div>
+        </form>
+
+        {preview ? (
+          <section className="import-rides-preview" aria-label="Import preview">
+            <h2>Preview Summary</h2>
+            <p>
+              Total rows: {preview.totalRows} | Valid rows: {preview.validRows} | Invalid rows:{' '}
+              {preview.invalidRows}
+            </p>
+
+            <p className="import-rides-duplicates">
+              Duplicate rows: {preview.duplicateRows}
+              {preview.requiresDuplicateResolution
+                ? ' | Resolve duplicates before starting import.'
+                : ' | No duplicate review required.'}
+            </p>
+
+            {preview.rows.length > 0 ? (
+              <ul>
+                {preview.rows.map((row) => (
+                  <li key={row.rowNumber}>
+                    Row {row.rowNumber}: {row.isValid ? 'Valid' : 'Invalid'}
+                    {row.errors.length > 0 ? (
+                      <ul>
+                        {row.errors.map((error) => (
+                          <li key={`${row.rowNumber}-${error.code}-${error.field ?? 'none'}`}>
+                            {error.field ?? 'Row'}: {error.message}
+                          </li>
+                        ))}
+                      </ul>
+                    ) : null}
+                  </li>
+                ))}
+              </ul>
+            ) : null}
+
+            <div className="import-rides-actions">
+              {!isDuplicateDialogOpen ? (
+                <button type="button" onClick={() => void onStartImport()} disabled={isStarting}>
+                  {isStarting ? 'Starting...' : 'Start Import'}
+                </button>
+              ) : null}
+            </div>
+          </section>
+        ) : null}
+
+        {status ? (
+          <ImportProgressPanel
+            status={status.status}
+            percentComplete={status.percentComplete ?? null}
+            etaMinutesRounded={status.etaMinutesRounded ?? null}
+            importedRows={status.importedRows}
+            skippedRows={status.skippedRows}
+            failedRows={status.failedRows}
+            isCancelling={isCancelling}
+            onCancel={() => void onCancelImport()}
+          />
+        ) : (
+          <p className="import-rides-placeholder">
+            Progress tracking and cancellation continue in the next implementation slice.
+          </p>
+        )}
+      </section>
+
+      <DuplicateResolutionDialog
+        isOpen={isDuplicateDialogOpen}
+        duplicateRows={duplicateRows}
+        overrideAllDuplicates={overrideAllDuplicates}
+        resolutions={duplicateResolutions}
+        isSubmitting={isStarting}
+        onClose={() => setIsDuplicateDialogOpen(false)}
+        onConfirm={() => void onConfirmDuplicateResolution()}
+        onOverrideAllDuplicatesChange={setOverrideAllDuplicates}
+        onResolutionChange={onResolutionChange}
+      />
+    </main>
+  )
+}
diff --git a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.css b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.css
index 2936a6f..1c16c50 100644
--- a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.css
+++ b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.css
@@ -19,6 +19,21 @@
   color: #152238;
 }
 
+.settings-import-link-wrapper {
+  margin: 0;
+}
+
+.settings-import-link {
+  color: #1f4f94;
+  font-weight: 600;
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
+.settings-import-link:hover {
+  color: #163869;
+}
+
 .settings-grid {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
diff --git a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx
index f35b938..8efafc5 100644
--- a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx
@@ -1,4 +1,5 @@
 import { useEffect, useState } from 'react'
+import { Link } from 'react-router-dom'
 import {
   getUserSettings,
   saveUserSettings,
@@ -222,6 +223,11 @@ export function SettingsPage() {
     <main className="settings-page">
       <section className="settings-card">
         <h1>Settings</h1>
+        <p className="settings-import-link-wrapper">
+          <Link className="settings-import-link" to="/rides/import">
+            Import Rides from CSV
+          </Link>
+        </p>
 
         {error ? (
           <p className="settings-error" role="alert">
diff --git a/src/BikeTracking.Frontend/src/services/import-api.ts b/src/BikeTracking.Frontend/src/services/import-api.ts
new file mode 100644
index 0000000..c08423b
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/services/import-api.ts
@@ -0,0 +1,202 @@
+import { type ApiResult, type ErrorResponse } from "./users-api";
+
+const API_BASE_URL =
+  (import.meta.env.VITE_API_BASE_URL as string | undefined)?.replace(
+    /\/$/,
+    "",
+  ) ?? "http://localhost:5436";
+
+const SESSION_KEY = "bike_tracking_auth_session";
+
+export interface ImportPreviewRequest {
+  fileName: string;
+  contentBase64: string;
+}
+
+export interface ImportValidationError {
+  rowNumber: number;
+  code: string;
+  message: string;
+  field?: string | null;
+}
+
+export interface ImportDuplicateMatch {
+  existingRideId: number;
+  existingRideDate: string;
+  existingMiles: number;
+}
+
+export interface ImportPreviewRow {
+  rowNumber: number;
+  date?: string | null;
+  miles?: number | null;
+  rideMinutes?: number | null;
+  temperature?: number | null;
+  tags?: string | null;
+  notes?: string | null;
+  isValid: boolean;
+  errors: ImportValidationError[];
+  duplicateMatches: ImportDuplicateMatch[];
+}
+
+export interface ImportPreviewResponse {
+  importJobId: number;
+  totalRows: number;
+  validRows: number;
+  invalidRows: number;
+  duplicateRows: number;
+  requiresDuplicateResolution: boolean;
+  rows: ImportPreviewRow[];
+}
+
+export interface ImportDuplicateResolution {
+  rowNumber: number;
+  action: "keep-existing" | "replace-with-import";
+}
+
+export interface ImportStartRequest {
+  importJobId: number;
+  overrideAllDuplicates: boolean;
+  resolutions?: ImportDuplicateResolution[] | null;
+}
+
+export interface ImportStartResponse {
+  importJobId: number;
+  status: string;
+  startedAtUtc: string;
+}
+
+export interface ImportStatusResponse {
+  importJobId: number;
+  status: string;
+  totalRows: number;
+  processedRows: number;
+  importedRows: number;
+  skippedRows: number;
+  failedRows: number;
+  percentComplete?: number | null;
+  etaMinutesRounded?: number | null;
+  createdAtUtc: string;
+  startedAtUtc?: string | null;
+  completedAtUtc?: string | null;
+  lastError?: string | null;
+}
+
+export interface ImportCancelResponse {
+  importJobId: number;
+  status: string;
+  processedRows: number;
+  importedRows: number;
+  skippedRows: number;
+  failedRows: number;
+  cancelledAtUtc: string;
+}
+
+function getAuthHeaders(contentTypeJson: boolean): Record<string, string> {
+  const headers: Record<string, string> = {};
+  if (contentTypeJson) {
+    headers["Content-Type"] = "application/json";
+  }
+
+  try {
+    const raw = sessionStorage.getItem(SESSION_KEY);
+    if (!raw) {
+      return headers;
+    }
+
+    const parsed = JSON.parse(raw) as { userId?: number };
+    if (typeof parsed.userId === "number" && parsed.userId > 0) {
+      headers["X-User-Id"] = parsed.userId.toString();
+    }
+  } catch {
+    // Ignore malformed auth session values.
+  }
+
+  return headers;
+}
+
+async function postJson<TSuccess>(
+  path: string,
+  payload: unknown,
+): Promise<ApiResult<TSuccess>> {
+  const response = await fetch(`${API_BASE_URL}${path}`, {
+    method: "POST",
+    headers: getAuthHeaders(true),
+    body: JSON.stringify(payload),
+  });
+
+  if (response.ok) {
+    return {
+      ok: true,
+      status: response.status,
+      data: (await response.json()) as TSuccess,
+    };
+  }
+
+  let parsedError: ErrorResponse | undefined;
+  try {
+    parsedError = (await response.json()) as ErrorResponse;
+  } catch {
+    parsedError = undefined;
+  }
+
+  return {
+    ok: false,
+    status: response.status,
+    error: parsedError,
+  };
+}
+
+async function getJson<TSuccess>(path: string): Promise<ApiResult<TSuccess>> {
+  const response = await fetch(`${API_BASE_URL}${path}`, {
+    headers: getAuthHeaders(false),
+  });
+
+  if (response.ok) {
+    return {
+      ok: true,
+      status: response.status,
+      data: (await response.json()) as TSuccess,
+    };
+  }
+
+  let parsedError: ErrorResponse | undefined;
+  try {
+    parsedError = (await response.json()) as ErrorResponse;
+  } catch {
+    parsedError = undefined;
+  }
+
+  return {
+    ok: false,
+    status: response.status,
+    error: parsedError,
+  };
+}
+
+export function previewImportCsv(
+  payload: ImportPreviewRequest,
+): Promise<ApiResult<ImportPreviewResponse>> {
+  return postJson<ImportPreviewResponse>("/api/imports/preview", payload);
+}
+
+export function startImportCsv(
+  payload: ImportStartRequest,
+): Promise<ApiResult<ImportStartResponse>> {
+  return postJson<ImportStartResponse>("/api/imports/start", payload);
+}
+
+export function getImportStatus(
+  importJobId: number,
+): Promise<ApiResult<ImportStatusResponse>> {
+  return getJson<ImportStatusResponse>(`/api/imports/${importJobId}/status`);
+}
+
+export function cancelImport(
+  importJobId: number,
+): Promise<ApiResult<ImportCancelResponse>> {
+  return postJson<ImportCancelResponse>(
+    `/api/imports/${importJobId}/cancel`,
+    {},
+  );
+}
diff --git a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
new file mode 100644
index 0000000..6b178ec
--- /dev/null
+++ b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
@@ -0,0 +1,116 @@
+import { expect, test } from "@playwright/test";
+import { createAndLoginUser, uniqueUser } from "./support/auth-helpers";
+import { recordRide } from "./support/ride-helpers";
+
+const TEST_PIN = "87654321";
+
+test.describe("013-csv-import e2e", () => {
+  test("upload preview and start import happy path", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-rides");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    const csvContent = [
+      "Date,Miles,Time,Temp,Tags,Notes",
+      "2026-04-01,12.5,45,60,commute,morning ride",
+      "2026-04-02,0,40,58,commute,invalid miles",
+    ].join("\n");
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(csvContent, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+
+    await expect(page.getByText(/total rows: 2/i)).toBeVisible();
+    await expect(page.getByText(/valid rows: 1/i)).toBeVisible();
+    await expect(page.getByText(/invalid rows: 1/i)).toBeVisible();
+
+    await page.getByRole("button", { name: /start import/i }).click();
+
+    await expect(page.getByText(/status: processing/i)).toBeVisible();
+  });
+
+  test("resolves a duplicate with keep existing", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-duplicate-keep");
+    await createAndLoginUser(page, userName, TEST_PIN);
+    await recordRide(page, {
+      rideDateTimeLocal: "2026-04-01T08:00",
+      miles: "12.5",
+      rideMinutes: "45",
+      temperature: "60",
+    });
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    const csvContent = [
+      "Date,Miles,Time,Temp,Tags,Notes",
+      "2026-04-01,12.5,45,60,commute,duplicate ride",
+    ].join("\n");
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(csvContent, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+
+    await expect(page.getByText(/duplicate rows: 1/i)).toBeVisible();
+    await page.getByRole("button", { name: /^start import$/i }).click();
+    await expect(
+      page.getByRole("dialog", { name: /duplicate resolution/i }),
+    ).toBeVisible();
+
+    await page.getByLabel(/row 1 keep existing/i).check();
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    await expect(page.getByText(/status: processing/i)).toBeVisible();
+  });
+
+  test("resolves a duplicate with replace-with-import", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-duplicate-replace");
+    await createAndLoginUser(page, userName, TEST_PIN);
+    await recordRide(page, {
+      rideDateTimeLocal: "2026-04-01T08:00",
+      miles: "12.5",
+      rideMinutes: "45",
+      temperature: "60",
+    });
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    const csvContent = [
+      "Date,Miles,Time,Temp,Tags,Notes",
+      "2026-04-01,12.5,45,60,commute,duplicate ride",
+    ].join("\n");
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(csvContent, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+
+    await expect(page.getByText(/duplicate rows: 1/i)).toBeVisible();
+    await page.getByRole("button", { name: /^start import$/i }).click();
+    await expect(
+      page.getByRole("dialog", { name: /duplicate resolution/i }),
+    ).toBeVisible();
+
+    await page.getByLabel(/row 1 replace with import/i).check();
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    await expect(page.getByText(/status: processing/i)).toBeVisible();
+  });
+});

From 12335b457b5e6f8eba17441e9158fae9f6e897b2 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Thu, 9 Apr 2026 14:20:09 +0000
Subject: [PATCH 3/9] refactor large CsvRideImportService

---
 .../Endpoints/ImportEndpointsTests.cs         |   2 +
 .../Imports/CsvRideImportService.cs           | 517 +++++++-----------
 .../Imports/IImportJobRepository.cs           |  52 ++
 .../Application/Imports/ImportJobProcessor.cs | 178 ++++++
 .../Persistence/EfImportJobRepository.cs      | 119 ++++
 src/BikeTracking.Api/Program.cs               |   2 +
 6 files changed, 546 insertions(+), 324 deletions(-)
 create mode 100644 src/BikeTracking.Api/Application/Imports/IImportJobRepository.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/EfImportJobRepository.cs

diff --git a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
index d9d36f5..fe6fe29 100644
--- a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
+++ b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
@@ -375,8 +375,10 @@ public static async Task<ImportApiHost> StartAsync()
                 options.UseInMemoryDatabase(dbName)
             );
             builder.Services.AddScoped<IDuplicateResolutionService, DuplicateResolutionService>();
+            builder.Services.AddScoped<IImportJobRepository, EfImportJobRepository>();
             builder.Services.AddScoped<ICsvRideImportService, CsvRideImportService>();
             builder.Services.AddScoped<IImportProgressNotifier, ImportProgressNotifier>();
+            builder.Services.AddSingleton<IImportJobProcessor, ImportJobProcessor>();
 
             var app = builder.Build();
             app.UseAuthentication();
diff --git a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
index f048d2a..5977047 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
@@ -1,17 +1,14 @@
 using System.Text;
 using System.Text.Json;
-using BikeTracking.Api.Application.Notifications;
 using BikeTracking.Api.Contracts;
-using BikeTracking.Api.Infrastructure.Persistence;
 using BikeTracking.Api.Infrastructure.Persistence.Entities;
-using Microsoft.EntityFrameworkCore;
 
 namespace BikeTracking.Api.Application.Imports;
 
 public sealed class CsvRideImportService(
-    BikeTrackingDbContext dbContext,
+    IImportJobRepository importJobRepository,
     IDuplicateResolutionService duplicateResolutionService,
-    IServiceScopeFactory serviceScopeFactory
+    IImportJobProcessor importJobProcessor
 ) : ICsvRideImportService
 {
     public async Task<ImportPreviewResponse> PreviewAsync(
@@ -27,68 +24,9 @@ CancellationToken cancellationToken
         var csvText = Encoding.UTF8.GetString(csvBytes);
         var parsedDocument = CsvParser.Parse(csvText);
 
-        var previewRows = new List<ImportPreviewRow>();
-        var importRows = new List<ImportRowEntity>();
-        var validRows = 0;
-        var duplicateCandidates = new List<ImportDuplicateCandidate>();
-
-        foreach (var parsedRow in parsedDocument.Rows)
-        {
-            var errors = CsvValidationRules.ValidateRow(parsedRow);
-            var isValid = errors.Count == 0;
-            if (isValid)
-            {
-                validRows += 1;
-            }
+        var (previewRows, importRows, validRows) = BuildRowData(parsedDocument);
 
-            CsvValidationRules.TryParseDate(parsedRow.Date, out var parsedDate);
-            CsvValidationRules.TryParseMiles(parsedRow.Miles, out var parsedMiles);
-            CsvValidationRules.TryParseRideMinutes(parsedRow.Time, out var parsedRideMinutes);
-            CsvValidationRules.TryParseTemperature(parsedRow.Temp, out var parsedTemp);
-
-            if (isValid && parsedDate != default && parsedMiles > 0)
-            {
-                duplicateCandidates.Add(
-                    new ImportDuplicateCandidate(parsedRow.RowNumber, parsedDate, parsedMiles)
-                );
-            }
-
-            previewRows.Add(
-                new ImportPreviewRow(
-                    RowNumber: parsedRow.RowNumber,
-                    Date: parsedRow.Date,
-                    Miles: parsedMiles,
-                    RideMinutes: parsedRideMinutes,
-                    Temperature: parsedTemp,
-                    Tags: parsedRow.Tags,
-                    Notes: parsedRow.Notes,
-                    IsValid: isValid,
-                    Errors: errors,
-                    DuplicateMatches: []
-                )
-            );
-
-            importRows.Add(
-                new ImportRowEntity
-                {
-                    RowNumber = parsedRow.RowNumber,
-                    RideDateLocal = CsvValidationRules.TryParseDate(parsedRow.Date, out var rowDate)
-                        ? rowDate
-                        : null,
-                    Miles = CsvValidationRules.TryParseMiles(parsedRow.Miles, out var rowMiles)
-                        ? rowMiles
-                        : null,
-                    RideMinutes = parsedRideMinutes,
-                    Temperature = parsedTemp,
-                    TagsRaw = parsedRow.Tags,
-                    Notes = parsedRow.Notes,
-                    ValidationStatus = isValid ? "valid" : "invalid",
-                    ValidationErrorsJson = isValid ? null : JsonSerializer.Serialize(errors),
-                    DuplicateStatus = "none",
-                    ProcessingStatus = isValid ? "pending" : "failed",
-                }
-            );
-        }
+        var duplicateCandidates = BuildDuplicateCandidates(previewRows);
 
         var duplicateLookup = await duplicateResolutionService.GetDuplicateMatchesAsync(
             riderId,
@@ -96,58 +34,20 @@ CancellationToken cancellationToken
             cancellationToken
         );
 
-        var duplicateRows = 0;
-        for (var index = 0; index < previewRows.Count; index++)
-        {
-            var row = previewRows[index];
-            if (!duplicateLookup.TryGetValue(row.RowNumber, out var matches))
-            {
-                continue;
-            }
-
-            duplicateRows += 1;
-            previewRows[index] = row with { DuplicateMatches = matches };
-        }
-
-        foreach (var entity in importRows)
-        {
-            if (!duplicateLookup.TryGetValue(entity.RowNumber, out var matches))
-            {
-                continue;
-            }
-
-            entity.DuplicateStatus = "duplicate";
-            entity.ExistingRideIdsJson = JsonSerializer.Serialize(
-                matches.Select(static x => x.ExistingRideId)
-            );
-        }
+        var duplicateRows = ApplyDuplicateMatches(previewRows, importRows, duplicateLookup);
 
         var totalRows = parsedDocument.Rows.Count;
         var invalidRows = totalRows - validRows;
 
-        var job = new ImportJobEntity
-        {
-            RiderId = riderId,
-            FileName = request.FileName,
-            Status = "awaiting-confirmation",
-            TotalRows = totalRows,
-            ProcessedRows = 0,
-            ImportedRows = 0,
-            SkippedRows = 0,
-            FailedRows = invalidRows,
-            CreatedAtUtc = DateTime.UtcNow,
-        };
-
-        dbContext.ImportJobs.Add(job);
-        await dbContext.SaveChangesAsync(cancellationToken);
-
-        foreach (var row in importRows)
-        {
-            row.ImportJobId = job.Id;
-        }
+        var job = await importJobRepository.CreateJobAsync(
+            riderId,
+            request.FileName,
+            totalRows,
+            invalidRows,
+            cancellationToken
+        );
 
-        dbContext.ImportRows.AddRange(importRows);
-        await dbContext.SaveChangesAsync(cancellationToken);
+        await importJobRepository.AddRowsAsync(job.Id, importRows, cancellationToken);
 
         return new ImportPreviewResponse(
             ImportJobId: job.Id,
@@ -166,8 +66,9 @@ public async Task<ImportStartResponse> StartAsync(
         CancellationToken cancellationToken
     )
     {
-        var hasActiveImport = await dbContext.ImportJobs.AnyAsync(
-            x => x.RiderId == riderId && x.Status == "processing" && x.Id != request.ImportJobId,
+        var hasActiveImport = await importJobRepository.HasActiveImportAsync(
+            riderId,
+            request.ImportJobId,
             cancellationToken
         );
 
@@ -176,8 +77,9 @@ CancellationToken cancellationToken
             throw new ImportConflictException("An import is already in progress.");
         }
 
-        var job = await dbContext.ImportJobs.SingleOrDefaultAsync(
-            x => x.Id == request.ImportJobId && x.RiderId == riderId,
+        var job = await importJobRepository.GetJobAsync(
+            riderId,
+            request.ImportJobId,
             cancellationToken
         );
 
@@ -191,50 +93,9 @@ CancellationToken cancellationToken
             throw new ArgumentException("Import job is not ready to start.");
         }
 
-        var jobRows = await dbContext
-            .ImportRows.Where(x => x.ImportJobId == job.Id)
-            .OrderBy(x => x.RowNumber)
-            .ToListAsync(cancellationToken);
-
-        var resolutionLookup = (request.Resolutions ?? []).ToDictionary(
-            static x => x.RowNumber,
-            static x => x.Action,
-            EqualityComparer<int>.Default
-        );
+        var jobRows = await importJobRepository.GetJobRowsAsync(job.Id, cancellationToken);
 
-        foreach (var row in jobRows.Where(x => x.DuplicateStatus == "duplicate"))
-        {
-            if (request.OverrideAllDuplicates)
-            {
-                row.DuplicateResolution = "override-all";
-                row.DuplicateStatus = "resolved";
-                continue;
-            }
-
-            if (!resolutionLookup.TryGetValue(row.RowNumber, out var action))
-            {
-                throw new ArgumentException(
-                    $"Duplicate row {row.RowNumber} requires a resolution or override-all."
-                );
-            }
-
-            if (action is not ("keep-existing" or "replace-with-import"))
-            {
-                throw new ArgumentException(
-                    $"Duplicate row {row.RowNumber} has an invalid resolution action."
-                );
-            }
-
-            row.DuplicateResolution = action;
-            row.DuplicateStatus = "resolved";
-
-            if (action == "keep-existing")
-            {
-                row.ProcessingStatus = "skipped";
-                job.SkippedRows += 1;
-                job.ProcessedRows += 1;
-            }
-        }
+        ResolveDuplicates(job, jobRows, request);
 
         job.OverrideAllDuplicates = request.OverrideAllDuplicates;
         job.Status = "processing";
@@ -246,177 +107,24 @@ CancellationToken cancellationToken
             DateTime.UtcNow
         );
 
-        await dbContext.SaveChangesAsync(cancellationToken);
+        await importJobRepository.SaveChangesAsync(cancellationToken);
 
-        _ = Task.Run(
-            async () => await ProcessImportJobAsync(riderId, job.Id, CancellationToken.None),
-            CancellationToken.None
-        );
+        importJobProcessor.Enqueue(riderId, job.Id);
 
         return new ImportStartResponse(job.Id, job.Status, job.StartedAtUtc.Value);
     }
 
-    private async Task ProcessImportJobAsync(
-        long riderId,
-        long importJobId,
-        CancellationToken cancellationToken
-    )
-    {
-        try
-        {
-            await using var scope = serviceScopeFactory.CreateAsyncScope();
-            var scopedDbContext = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
-            var scopedNotifier =
-                scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
-
-            var job = await scopedDbContext.ImportJobs.SingleOrDefaultAsync(
-                x => x.Id == importJobId && x.RiderId == riderId,
-                cancellationToken
-            );
-            if (job is null || job.Status != "processing")
-            {
-                return;
-            }
-
-            var rowsToProcess = await scopedDbContext
-                .ImportRows.Where(x =>
-                    x.ImportJobId == importJobId && x.ProcessingStatus == "pending"
-                )
-                .OrderBy(x => x.RowNumber)
-                .ToListAsync(cancellationToken);
-
-            var sentMilestones = ImportProgressEstimator
-                .GetReachedMilestones(job.TotalRows, job.ProcessedRows)
-                .ToHashSet();
-
-            // Delay the first unit of processing so Start can return a stable processing state.
-            await Task.Delay(TimeSpan.FromMilliseconds(250), cancellationToken);
-
-            foreach (var row in rowsToProcess)
-            {
-                await scopedDbContext.Entry(job).ReloadAsync(cancellationToken);
-                if (job.Status == "cancelled")
-                {
-                    break;
-                }
-
-                await Task.Delay(TimeSpan.FromMilliseconds(75), cancellationToken);
-
-                row.ProcessingStatus = "imported";
-                job.ImportedRows += 1;
-                job.ProcessedRows += 1;
-                job.EtaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
-                    job.TotalRows,
-                    job.ProcessedRows,
-                    job.StartedAtUtc,
-                    DateTime.UtcNow
-                );
-
-                await scopedDbContext.SaveChangesAsync(cancellationToken);
-
-                var milestones = ImportProgressEstimator.GetReachedMilestones(
-                    job.TotalRows,
-                    job.ProcessedRows
-                );
-                foreach (var milestone in milestones)
-                {
-                    if (!sentMilestones.Add(milestone))
-                    {
-                        continue;
-                    }
-
-                    await scopedNotifier.NotifyProgressAsync(
-                        CreateProgressNotification(job, riderId),
-                        cancellationToken
-                    );
-                }
-            }
-
-            await scopedDbContext.Entry(job).ReloadAsync(cancellationToken);
-            if (job.Status != "cancelled")
-            {
-                job.Status = "completed";
-                job.CompletedAtUtc = DateTime.UtcNow;
-                job.EtaMinutesRounded = 0;
-                await scopedDbContext.SaveChangesAsync(cancellationToken);
-            }
-
-            await scopedNotifier.NotifyProgressAsync(
-                CreateProgressNotification(job, riderId),
-                cancellationToken
-            );
-        }
-        catch
-        {
-            await MarkImportAsFailedAsync(riderId, importJobId, cancellationToken);
-        }
-    }
-
-    private async Task MarkImportAsFailedAsync(
+    public async Task<ImportStatusResponse?> GetStatusAsync(
         long riderId,
         long importJobId,
         CancellationToken cancellationToken
     )
     {
-        await using var scope = serviceScopeFactory.CreateAsyncScope();
-        var scopedDbContext = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
-        var scopedNotifier = scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
-
-        var job = await scopedDbContext.ImportJobs.SingleOrDefaultAsync(
-            x => x.Id == importJobId && x.RiderId == riderId,
-            cancellationToken
-        );
-        if (job is null || job.Status == "cancelled")
-        {
-            return;
-        }
-
-        job.Status = "failed";
-        job.LastError = "Import processing failed.";
-        job.CompletedAtUtc = DateTime.UtcNow;
-        await scopedDbContext.SaveChangesAsync(cancellationToken);
-
-        await scopedNotifier.NotifyProgressAsync(
-            CreateProgressNotification(job, riderId),
+        var job = await importJobRepository.GetJobReadOnlyAsync(
+            riderId,
+            importJobId,
             cancellationToken
         );
-    }
-
-    private static ImportProgressNotification CreateProgressNotification(
-        ImportJobEntity job,
-        long riderId
-    )
-    {
-        return new ImportProgressNotification(
-            RiderId: riderId,
-            ImportJobId: job.Id,
-            Status: job.Status,
-            PercentComplete: ImportProgressEstimator.CalculatePercentComplete(
-                job.TotalRows,
-                job.ProcessedRows
-            ),
-            EtaMinutesRounded: job.EtaMinutesRounded,
-            ProcessedRows: job.ProcessedRows,
-            TotalRows: job.TotalRows,
-            ImportedRows: job.ImportedRows,
-            SkippedRows: job.SkippedRows,
-            FailedRows: job.FailedRows,
-            EmittedAtUtc: DateTime.UtcNow
-        );
-    }
-
-    public async Task<ImportStatusResponse?> GetStatusAsync(
-        long riderId,
-        long importJobId,
-        CancellationToken cancellationToken
-    )
-    {
-        var job = await dbContext
-            .ImportJobs.AsNoTracking()
-            .SingleOrDefaultAsync(
-                x => x.Id == importJobId && x.RiderId == riderId,
-                cancellationToken
-            );
 
         if (job is null)
         {
@@ -459,10 +167,7 @@ CancellationToken cancellationToken
         CancellationToken cancellationToken
     )
     {
-        var job = await dbContext.ImportJobs.SingleOrDefaultAsync(
-            x => x.Id == importJobId && x.RiderId == riderId,
-            cancellationToken
-        );
+        var job = await importJobRepository.GetJobAsync(riderId, importJobId, cancellationToken);
 
         if (job is null)
         {
@@ -474,7 +179,7 @@ CancellationToken cancellationToken
             job.Status = "cancelled";
             job.CompletedAtUtc = DateTime.UtcNow;
             job.EtaMinutesRounded = null;
-            await dbContext.SaveChangesAsync(cancellationToken);
+            await importJobRepository.SaveChangesAsync(cancellationToken);
         }
 
         return new ImportCancelResponse(
@@ -487,4 +192,168 @@ CancellationToken cancellationToken
             CancelledAtUtc: job.CompletedAtUtc ?? DateTime.UtcNow
         );
     }
+
+    private static (
+        List<ImportPreviewRow> PreviewRows,
+        List<ImportRowEntity> ImportRows,
+        int ValidRows
+    ) BuildRowData(ParsedCsvDocument parsedDocument)
+    {
+        var previewRows = new List<ImportPreviewRow>();
+        var importRows = new List<ImportRowEntity>();
+        var validRows = 0;
+
+        foreach (var parsedRow in parsedDocument.Rows)
+        {
+            var errors = CsvValidationRules.ValidateRow(parsedRow);
+            var isValid = errors.Count == 0;
+            if (isValid)
+            {
+                validRows += 1;
+            }
+
+            CsvValidationRules.TryParseDate(parsedRow.Date, out var parsedDate);
+            CsvValidationRules.TryParseMiles(parsedRow.Miles, out var parsedMiles);
+            CsvValidationRules.TryParseRideMinutes(parsedRow.Time, out var parsedRideMinutes);
+            CsvValidationRules.TryParseTemperature(parsedRow.Temp, out var parsedTemp);
+
+            previewRows.Add(
+                new ImportPreviewRow(
+                    RowNumber: parsedRow.RowNumber,
+                    Date: parsedRow.Date,
+                    Miles: parsedMiles,
+                    RideMinutes: parsedRideMinutes,
+                    Temperature: parsedTemp,
+                    Tags: parsedRow.Tags,
+                    Notes: parsedRow.Notes,
+                    IsValid: isValid,
+                    Errors: errors,
+                    DuplicateMatches: []
+                )
+            );
+
+            importRows.Add(
+                new ImportRowEntity
+                {
+                    RowNumber = parsedRow.RowNumber,
+                    RideDateLocal = CsvValidationRules.TryParseDate(parsedRow.Date, out var rowDate)
+                        ? rowDate
+                        : null,
+                    Miles = CsvValidationRules.TryParseMiles(parsedRow.Miles, out var rowMiles)
+                        ? rowMiles
+                        : null,
+                    RideMinutes = parsedRideMinutes,
+                    Temperature = parsedTemp,
+                    TagsRaw = parsedRow.Tags,
+                    Notes = parsedRow.Notes,
+                    ValidationStatus = isValid ? "valid" : "invalid",
+                    ValidationErrorsJson = isValid ? null : JsonSerializer.Serialize(errors),
+                    DuplicateStatus = "none",
+                    ProcessingStatus = isValid ? "pending" : "failed",
+                }
+            );
+        }
+
+        return (previewRows, importRows, validRows);
+    }
+
+    private static IReadOnlyList<ImportDuplicateCandidate> BuildDuplicateCandidates(
+        List<ImportPreviewRow> previewRows
+    )
+    {
+        return previewRows
+            .Where(row => row.IsValid && row.Miles is > 0)
+            .Where(row =>
+                CsvValidationRules.TryParseDate(row.Date, out var date) && date != default
+            )
+            .Select(row =>
+            {
+                CsvValidationRules.TryParseDate(row.Date, out var date);
+                return new ImportDuplicateCandidate(row.RowNumber, date, row.Miles!.Value);
+            })
+            .ToArray();
+    }
+
+    private static int ApplyDuplicateMatches(
+        List<ImportPreviewRow> previewRows,
+        List<ImportRowEntity> importRows,
+        IReadOnlyDictionary<int, IReadOnlyList<ImportDuplicateMatch>> duplicateLookup
+    )
+    {
+        var duplicateRows = 0;
+
+        for (var index = 0; index < previewRows.Count; index++)
+        {
+            var row = previewRows[index];
+            if (!duplicateLookup.TryGetValue(row.RowNumber, out var matches))
+            {
+                continue;
+            }
+
+            duplicateRows += 1;
+            previewRows[index] = row with { DuplicateMatches = matches };
+        }
+
+        foreach (var entity in importRows)
+        {
+            if (!duplicateLookup.TryGetValue(entity.RowNumber, out var matches))
+            {
+                continue;
+            }
+
+            entity.DuplicateStatus = "duplicate";
+            entity.ExistingRideIdsJson = JsonSerializer.Serialize(
+                matches.Select(static x => x.ExistingRideId)
+            );
+        }
+
+        return duplicateRows;
+    }
+
+    private static void ResolveDuplicates(
+        ImportJobEntity job,
+        IReadOnlyList<ImportRowEntity> jobRows,
+        ImportStartRequest request
+    )
+    {
+        var resolutionLookup = (request.Resolutions ?? []).ToDictionary(
+            static x => x.RowNumber,
+            static x => x.Action,
+            EqualityComparer<int>.Default
+        );
+
+        foreach (var row in jobRows.Where(x => x.DuplicateStatus == "duplicate"))
+        {
+            if (request.OverrideAllDuplicates)
+            {
+                row.DuplicateResolution = "override-all";
+                row.DuplicateStatus = "resolved";
+                continue;
+            }
+
+            if (!resolutionLookup.TryGetValue(row.RowNumber, out var action))
+            {
+                throw new ArgumentException(
+                    $"Duplicate row {row.RowNumber} requires a resolution or override-all."
+                );
+            }
+
+            if (action is not ("keep-existing" or "replace-with-import"))
+            {
+                throw new ArgumentException(
+                    $"Duplicate row {row.RowNumber} has an invalid resolution action."
+                );
+            }
+
+            row.DuplicateResolution = action;
+            row.DuplicateStatus = "resolved";
+
+            if (action == "keep-existing")
+            {
+                row.ProcessingStatus = "skipped";
+                job.SkippedRows += 1;
+                job.ProcessedRows += 1;
+            }
+        }
+    }
 }
diff --git a/src/BikeTracking.Api/Application/Imports/IImportJobRepository.cs b/src/BikeTracking.Api/Application/Imports/IImportJobRepository.cs
new file mode 100644
index 0000000..a33122b
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/IImportJobRepository.cs
@@ -0,0 +1,52 @@
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public interface IImportJobRepository
+{
+    Task<ImportJobEntity> CreateJobAsync(
+        long riderId,
+        string fileName,
+        int totalRows,
+        int invalidRows,
+        CancellationToken cancellationToken
+    );
+
+    Task AddRowsAsync(
+        long importJobId,
+        IReadOnlyList<ImportRowEntity> rows,
+        CancellationToken cancellationToken
+    );
+
+    Task<ImportJobEntity?> GetJobAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task<ImportJobEntity?> GetJobReadOnlyAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task<bool> HasActiveImportAsync(
+        long riderId,
+        long excludeJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task<IReadOnlyList<ImportRowEntity>> GetJobRowsAsync(
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task<IReadOnlyList<ImportRowEntity>> GetPendingRowsAsync(
+        long importJobId,
+        CancellationToken cancellationToken
+    );
+
+    Task ReloadJobAsync(ImportJobEntity job, CancellationToken cancellationToken);
+
+    Task SaveChangesAsync(CancellationToken cancellationToken);
+}
diff --git a/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs b/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
new file mode 100644
index 0000000..79288b2
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
@@ -0,0 +1,178 @@
+using BikeTracking.Api.Application.Notifications;
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+
+namespace BikeTracking.Api.Application.Imports;
+
+public interface IImportJobProcessor
+{
+    void Enqueue(long riderId, long importJobId);
+}
+
+public sealed class ImportJobProcessor(IServiceScopeFactory serviceScopeFactory)
+    : IImportJobProcessor
+{
+    public void Enqueue(long riderId, long importJobId)
+    {
+        _ = Task.Run(
+            async () => await ProcessAsync(riderId, importJobId, CancellationToken.None),
+            CancellationToken.None
+        );
+    }
+
+    private async Task ProcessAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        try
+        {
+            await using var scope = serviceScopeFactory.CreateAsyncScope();
+            var repository = scope.ServiceProvider.GetRequiredService<IImportJobRepository>();
+            var notifier = scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
+
+            var job = await repository.GetJobAsync(riderId, importJobId, cancellationToken);
+            if (job is null || job.Status != "processing")
+            {
+                return;
+            }
+
+            var rowsToProcess = await repository.GetPendingRowsAsync(
+                importJobId,
+                cancellationToken
+            );
+
+            var sentMilestones = ImportProgressEstimator
+                .GetReachedMilestones(job.TotalRows, job.ProcessedRows)
+                .ToHashSet();
+
+            // Delay the first unit of processing so Start can return a stable processing state.
+            await Task.Delay(TimeSpan.FromMilliseconds(250), cancellationToken);
+
+            foreach (var row in rowsToProcess)
+            {
+                await repository.ReloadJobAsync(job, cancellationToken);
+                if (job.Status == "cancelled")
+                {
+                    break;
+                }
+
+                await Task.Delay(TimeSpan.FromMilliseconds(75), cancellationToken);
+
+                row.ProcessingStatus = "imported";
+                job.ImportedRows += 1;
+                job.ProcessedRows += 1;
+                job.EtaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
+                    job.TotalRows,
+                    job.ProcessedRows,
+                    job.StartedAtUtc,
+                    DateTime.UtcNow
+                );
+
+                await repository.SaveChangesAsync(cancellationToken);
+
+                await EmitMilestoneNotificationsAsync(
+                    job,
+                    riderId,
+                    sentMilestones,
+                    notifier,
+                    cancellationToken
+                );
+            }
+
+            await repository.ReloadJobAsync(job, cancellationToken);
+            if (job.Status != "cancelled")
+            {
+                job.Status = "completed";
+                job.CompletedAtUtc = DateTime.UtcNow;
+                job.EtaMinutesRounded = 0;
+                await repository.SaveChangesAsync(cancellationToken);
+            }
+
+            await notifier.NotifyProgressAsync(
+                CreateProgressNotification(job, riderId),
+                cancellationToken
+            );
+        }
+        catch
+        {
+            await MarkAsFailedAsync(riderId, importJobId, cancellationToken);
+        }
+    }
+
+    private async Task MarkAsFailedAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        await using var scope = serviceScopeFactory.CreateAsyncScope();
+        var repository = scope.ServiceProvider.GetRequiredService<IImportJobRepository>();
+        var notifier = scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
+
+        var job = await repository.GetJobAsync(riderId, importJobId, cancellationToken);
+        if (job is null || job.Status == "cancelled")
+        {
+            return;
+        }
+
+        job.Status = "failed";
+        job.LastError = "Import processing failed.";
+        job.CompletedAtUtc = DateTime.UtcNow;
+        await repository.SaveChangesAsync(cancellationToken);
+
+        await notifier.NotifyProgressAsync(
+            CreateProgressNotification(job, riderId),
+            cancellationToken
+        );
+    }
+
+    private static async Task EmitMilestoneNotificationsAsync(
+        ImportJobEntity job,
+        long riderId,
+        HashSet<int> sentMilestones,
+        IImportProgressNotifier notifier,
+        CancellationToken cancellationToken
+    )
+    {
+        var milestones = ImportProgressEstimator.GetReachedMilestones(
+            job.TotalRows,
+            job.ProcessedRows
+        );
+        foreach (var milestone in milestones)
+        {
+            if (!sentMilestones.Add(milestone))
+            {
+                continue;
+            }
+
+            await notifier.NotifyProgressAsync(
+                CreateProgressNotification(job, riderId),
+                cancellationToken
+            );
+        }
+    }
+
+    internal static ImportProgressNotification CreateProgressNotification(
+        ImportJobEntity job,
+        long riderId
+    )
+    {
+        return new ImportProgressNotification(
+            RiderId: riderId,
+            ImportJobId: job.Id,
+            Status: job.Status,
+            PercentComplete: ImportProgressEstimator.CalculatePercentComplete(
+                job.TotalRows,
+                job.ProcessedRows
+            ),
+            EtaMinutesRounded: job.EtaMinutesRounded,
+            ProcessedRows: job.ProcessedRows,
+            TotalRows: job.TotalRows,
+            ImportedRows: job.ImportedRows,
+            SkippedRows: job.SkippedRows,
+            FailedRows: job.FailedRows,
+            EmittedAtUtc: DateTime.UtcNow
+        );
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/EfImportJobRepository.cs b/src/BikeTracking.Api/Infrastructure/Persistence/EfImportJobRepository.cs
new file mode 100644
index 0000000..ada0945
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/EfImportJobRepository.cs
@@ -0,0 +1,119 @@
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace BikeTracking.Api.Infrastructure.Persistence;
+
+public sealed class EfImportJobRepository(BikeTrackingDbContext dbContext) : IImportJobRepository
+{
+    public async Task<ImportJobEntity> CreateJobAsync(
+        long riderId,
+        string fileName,
+        int totalRows,
+        int invalidRows,
+        CancellationToken cancellationToken
+    )
+    {
+        var job = new ImportJobEntity
+        {
+            RiderId = riderId,
+            FileName = fileName,
+            Status = "awaiting-confirmation",
+            TotalRows = totalRows,
+            ProcessedRows = 0,
+            ImportedRows = 0,
+            SkippedRows = 0,
+            FailedRows = invalidRows,
+            CreatedAtUtc = DateTime.UtcNow,
+        };
+
+        dbContext.ImportJobs.Add(job);
+        await dbContext.SaveChangesAsync(cancellationToken);
+        return job;
+    }
+
+    public async Task AddRowsAsync(
+        long importJobId,
+        IReadOnlyList<ImportRowEntity> rows,
+        CancellationToken cancellationToken
+    )
+    {
+        foreach (var row in rows)
+        {
+            row.ImportJobId = importJobId;
+        }
+
+        dbContext.ImportRows.AddRange(rows);
+        await dbContext.SaveChangesAsync(cancellationToken);
+    }
+
+    public async Task<ImportJobEntity?> GetJobAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        return await dbContext.ImportJobs.SingleOrDefaultAsync(
+            x => x.Id == importJobId && x.RiderId == riderId,
+            cancellationToken
+        );
+    }
+
+    public async Task<ImportJobEntity?> GetJobReadOnlyAsync(
+        long riderId,
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        return await dbContext
+            .ImportJobs.AsNoTracking()
+            .SingleOrDefaultAsync(
+                x => x.Id == importJobId && x.RiderId == riderId,
+                cancellationToken
+            );
+    }
+
+    public async Task<bool> HasActiveImportAsync(
+        long riderId,
+        long excludeJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        return await dbContext.ImportJobs.AnyAsync(
+            x => x.RiderId == riderId && x.Status == "processing" && x.Id != excludeJobId,
+            cancellationToken
+        );
+    }
+
+    public async Task<IReadOnlyList<ImportRowEntity>> GetJobRowsAsync(
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        return await dbContext
+            .ImportRows.Where(x => x.ImportJobId == importJobId)
+            .OrderBy(x => x.RowNumber)
+            .ToListAsync(cancellationToken);
+    }
+
+    public async Task<IReadOnlyList<ImportRowEntity>> GetPendingRowsAsync(
+        long importJobId,
+        CancellationToken cancellationToken
+    )
+    {
+        return await dbContext
+            .ImportRows.Where(x => x.ImportJobId == importJobId && x.ProcessingStatus == "pending")
+            .OrderBy(x => x.RowNumber)
+            .ToListAsync(cancellationToken);
+    }
+
+    public async Task ReloadJobAsync(ImportJobEntity job, CancellationToken cancellationToken)
+    {
+        await dbContext.Entry(job).ReloadAsync(cancellationToken);
+    }
+
+    public async Task SaveChangesAsync(CancellationToken cancellationToken)
+    {
+        await dbContext.SaveChangesAsync(cancellationToken);
+    }
+}
diff --git a/src/BikeTracking.Api/Program.cs b/src/BikeTracking.Api/Program.cs
index f0f8331..6340a65 100644
--- a/src/BikeTracking.Api/Program.cs
+++ b/src/BikeTracking.Api/Program.cs
@@ -56,6 +56,8 @@
 builder.Services.AddScoped<ICsvRideImportService, CsvRideImportService>();
 builder.Services.AddScoped<IDuplicateResolutionService, DuplicateResolutionService>();
 builder.Services.AddScoped<IImportProgressNotifier, ImportProgressNotifier>();
+builder.Services.AddScoped<IImportJobRepository, EfImportJobRepository>();
+builder.Services.AddSingleton<IImportJobProcessor, ImportJobProcessor>();
 builder.Services.AddScoped<IGasPriceLookupService, EiaGasPriceLookupService>();
 builder.Services.AddScoped<IWeatherLookupService, OpenMeteoWeatherLookupService>();
 

From 1369ff21286ca4ff8660db9c925ca3122aa56eb4 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Thu, 9 Apr 2026 21:03:32 +0000
Subject: [PATCH 4/9] Implement weekly CSV import enrichment

---
 specs/013-csv-ride-import/spec.md             |  50 +-
 specs/013-csv-ride-import/tasks.md            |  60 +-
 .../Application/GasPriceLookupServiceTests.cs |   3 +
 .../Imports/CsvRideImportServiceTests.cs      |  84 +++
 .../Endpoints/RidesEndpointsTests.cs          |  10 +
 .../MigrationTestCoveragePolicyTests.cs       |   2 +
 .../Imports/CsvRideImportService.cs           |  72 +-
 .../Imports/GasPriceWeekKeyHelper.cs          |  30 +
 .../Application/Imports/ImportJobProcessor.cs | 350 +++++++++-
 .../Rides/GasPriceLookupService.cs            |  42 +-
 src/BikeTracking.Api/BikeTracking.Api.http    |  73 ++
 .../Persistence/BikeTrackingDbContext.cs      |   2 +
 .../Entities/GasPriceLookupEntity.cs          |   6 +
 ...AddGasPriceWeeklyDeduplication.Designer.cs | 653 ++++++++++++++++++
 ...09150320_AddGasPriceWeeklyDeduplication.cs |  62 ++
 .../BikeTrackingDbContextModelSnapshot.cs     |   6 +
 src/BikeTracking.Frontend/src/App.test.tsx    |  58 ++
 .../pages/import-rides/ImportRidesPage.css    |   2 +-
 .../src/pages/settings/SettingsPage.test.tsx  |  34 +
 .../tests/e2e/import-rides.spec.ts            | 228 +++++-
 20 files changed, 1738 insertions(+), 89 deletions(-)
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs
 create mode 100644 src/BikeTracking.Api/Application/Imports/GasPriceWeekKeyHelper.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.Designer.cs
 create mode 100644 src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.cs
 create mode 100644 src/BikeTracking.Frontend/src/App.test.tsx

diff --git a/specs/013-csv-ride-import/spec.md b/specs/013-csv-ride-import/spec.md
index ecba3ac..0a8a332 100644
--- a/specs/013-csv-ride-import/spec.md
+++ b/specs/013-csv-ride-import/spec.md
@@ -66,20 +66,29 @@ Because importing many rides (with gas price and weather enrichment) can take a
 
 ### User Story 4 - Gas Price and Weather Enrichment (Priority: P2)
 
-For each imported ride, the system automatically attempts to fill in gas price and weather data. It first checks the local cache: if cached gas price data exists for that ride's date, it is attached; if cached weather data exists for the ride's date and hour, it is attached. When no cached data exists, the system makes an external API lookup to fetch the missing data, caches the result for future use, and attaches it to the ride. If an external lookup fails, the system retries once; if the retry also fails, enrichment is skipped for that field on that ride and the import continues.
+For each imported ride, the system automatically attempts to fill in gas price and weather data using a cache-first, weekly-dedup strategy.
 
-**Why this priority**: Enrichment adds significant value to imported rides, making them consistent with manually-entered rides. External lookups for uncached dates ensure imported historical rides are as complete as possible. However, enrichment depends on the core import working correctly and is not strictly required for ride records to be useful.
+**Gas price (weekly window)**: Gas prices are cached and fetched per Sunday–Saturday week, not per individual date, because the EIA API reports weekly national average prices. The system computes the Sunday that begins the week containing the ride's local date and uses that as the cache key. All rides in the same week share one cache entry — at most one external API call is made per distinct week across the entire import. If a cached entry for that week already exists, it is reused with no external call.
 
-**Independent Test**: Can be tested by importing a CSV with rides on dates that have cached data (verifying cache hits) and dates that do not (verifying external lookups are triggered and results cached). Also test with a simulated API failure to confirm retry-then-skip behavior.
+**Weather (date + noon default)**: Weather is cached per date and UTC hour at the rider's saved location. Because the CSV Time column represents ride *duration* (minutes), not a clock departure time, the system cannot derive a ride start hour from the CSV. Instead, weather is fetched for the ride's local date at noon (12:00 local, converted to UTC) as a consistent default. This matches the same fallback hour used for manual ride entry when no exact departure time is set.
+
+**Failure handling**: If an external lookup fails, the system retries once. If the retry also fails, enrichment is skipped for that field on that ride and the import continues.
+
+**Why this priority**: Enrichment adds significant value to imported rides, making them consistent with manually-entered rides. The weekly gas dedup strategy dramatically reduces external API calls for typical imports (e.g., a 200-row commute history spanning ~40 weeks needs at most 40 gas lookups instead of 200). However, enrichment depends on the core import working correctly and is not strictly required for ride records to be useful.
+
+**Independent Test**: Can be tested by importing a CSV with rides on dates that have cached data (verifying cache hits), dates that do not (verifying external lookups are triggered and results cached), multiple rides in the same week (verifying one lookup shared across all), and a simulated API failure (confirming retry-then-skip behavior).
 
 **Acceptance Scenarios**:
 
-1. **Given** a cached gas price exists for 2026-03-10, **When** a CSV row dated 2026-03-10 is imported, **Then** the resulting ride record includes the cached gas price (no external call made).
-2. **Given** no cached gas price exists for 2026-02-20, **When** a CSV row dated 2026-02-20 is imported, **Then** the system fetches the gas price from the external API, caches it, and attaches it to the ride record.
+1. **Given** a cached gas price entry exists for the week of 2026-03-08 (Sunday) through 2026-03-14 (Saturday), **When** a CSV row dated 2026-03-10 (Tuesday) is imported, **Then** the resulting ride record includes the cached gas price (no external call made).
+2. **Given** no cached gas price exists for the week of 2026-02-15 (Sunday) through 2026-02-21 (Saturday), **When** a CSV row dated 2026-02-20 (Friday) is imported, **Then** the system fetches the gas price from the external API for that week, caches one entry keyed to 2026-02-15, and attaches the price to the ride record.
 3. **Given** no cached gas price exists and the external API call fails, **When** the system retries once and the retry also fails, **Then** the ride record is created with gas price left empty and the import continues.
-4. **Given** a cached weather record exists for 2026-03-10 at the hour matching the ride's time, **When** that CSV row is imported, **Then** the ride record includes the cached weather snapshot (temperature, wind, humidity, etc.).
-5. **Given** no cached weather exists for 2026-03-10 at 14:00, **When** a CSV row dated 2026-03-10 with Time 14:30 is imported, **Then** the system fetches weather for that date/hour from the external API, caches it, and attaches it.
-6. **Given** a CSV row includes a Temp value and cached or fetched weather also has temperature data, **When** the row is imported, **Then** the user-provided Temp from the CSV takes precedence (enrichment fills only fields not supplied in the CSV).
+4. **Given** a CSV contains two rows dated 2026-03-10 (Tuesday) and 2026-03-12 (Thursday) — both in the week of 2026-03-08 — and no cache entry exists for that week, **When** the import runs, **Then** exactly one external gas price API call is made, one cache entry is written, and both ride records receive the same gas price.
+5. **Given** a CSV contains one row dated 2026-03-07 (Saturday) and one row dated 2026-03-08 (Sunday), **When** the import runs, **Then** two separate gas price lookups are made (one for the week of 2026-03-01, one for the week of 2026-03-08) because the dates fall in different Sunday–Saturday windows.
+6. **Given** a cached weather record exists for 2026-03-10 at 12:00 UTC (noon) at the rider's location, **When** a CSV row dated 2026-03-10 is imported, **Then** the ride record includes the cached weather snapshot (temperature, wind, humidity, etc.) — the noon-default hour is matched.
+7. **Given** no cached weather exists for 2026-03-14 at noon UTC at the rider's location, **When** a CSV row dated 2026-03-14 is imported, **Then** the system fetches weather for 2026-03-14 at noon UTC, caches it keyed to that date and hour, and attaches it to the ride record.
+8. **Given** no cached weather data and the external API call fails, **When** the system retries once and the retry also fails, **Then** the ride record is created without weather data and the import continues.
+9. **Given** a CSV row includes a Temp value and cached or fetched weather also has temperature data, **When** the row is imported, **Then** the user-provided Temp from the CSV takes precedence (enrichment fills only fields not supplied in the CSV).
 
 ---
 
@@ -128,9 +137,10 @@ The import functionality is discoverable from the Settings page via a clearly la
 - **FR-010**: System MUST provide an "Override All Duplicates" option (available before import starts or at the first duplicate prompt) that bypasses all subsequent duplicate checks and imports all rows.
 - **FR-011**: System MUST send real-time progress notifications at 25% processing increments (25%, 50%, 75%, 100%) via a persistent connection.
 - **FR-012**: System MUST display an estimated time remaining (rounded to the nearest 5 minutes) once enough rows have been processed to compute a rate, showing "Estimating…" until that point.
-- **FR-013**: System MUST enrich each imported ride with cached gas price data when a cache entry exists for that ride's date.
-- **FR-014**: System MUST enrich each imported ride with cached weather data when a cache entry exists for the ride's date and nearest hour.
-- **FR-015**: System MUST attempt external API lookups for gas price and weather data when no cached data exists for a ride's date (gas price) or date and hour (weather). On failure, the system MUST retry once; if the retry also fails, enrichment for that field is skipped and the import continues.
+- **FR-013**: System MUST enrich each imported ride with cached gas price data when a cache entry exists for the Sunday–Saturday week window containing the ride's local date.
+- **FR-014**: System MUST enrich each imported ride with cached weather data when a cache entry exists for the ride's local date at noon (12:00 local, converted to UTC) at the rider's saved location.
+- **FR-015**: System MUST attempt external API lookups for gas price and weather data when no cached data exists for the ride's week window (gas price) or date at noon UTC (weather). On failure, the system MUST retry once; if the retry also fails, enrichment for that field is skipped and the import continues.
+- **FR-025**: System MUST deduplicate gas price API calls by week window during import. Before processing rows, the system MUST group all valid rows by their Sunday–Saturday week key, fetch or load the cache for each distinct week (at most one external call per week), and apply the resolved price to all rows sharing that week. The week key is the Sunday date that begins the ISO-week window containing the ride's local date.
 - **FR-016**: System MUST give CSV-provided values (e.g., Temp) precedence over cached data when both are available for the same field.
 - **FR-017**: System MUST prevent concurrent imports for the same rider.
 - **FR-018**: System MUST continue processing the import server-side even if the rider navigates away from the import page.
@@ -144,9 +154,10 @@ The import functionality is discoverable from the Settings page via a clearly la
 ### Key Entities
 
 - **Import Job**: Represents a single CSV import operation. Attributes: rider identity, upload timestamp, file name, total row count, processed row count, status (pending, validating, awaiting-confirmation, processing, completed, failed), estimated completion time.
-- **Import Row**: A single parsed row from the CSV. Attributes: row number, date, miles, time (duration), temperature, tags, notes, validation status (valid/invalid with error details), duplicate status (none/duplicate), resolution (import/skip/override).
+- **Import Row**: A single parsed row from the CSV. Attributes: row number, date, miles, time (duration in minutes), temperature, tags, notes, validation status (valid/invalid with error details), duplicate status (none/duplicate), resolution (import/skip/override).
 - **Import Summary**: The outcome of a completed import. Attributes: total rows, rides imported count, rides skipped count, rows failed count, enrichment stats (gas prices attached count, weather snapshots attached count), duration of import.
 - **Duplicate Conflict**: Represents a date-based conflict between an incoming CSV row and existing ride(s). Attributes: conflicting date, existing ride details (miles, time, temp, tags, notes), incoming row details, rider resolution choice.
+- **Gas Price Week Key**: The Sunday date that starts the Sunday–Saturday week window containing a ride's local date. Used as the gas price cache lookup key so that all rides within the same week share one cache entry.
 
 ## Assumptions
 
@@ -154,11 +165,14 @@ The import functionality is discoverable from the Settings page via a clearly la
 - Date formats attempted during parsing include: YYYY-MM-DD, MM/DD/YYYY, M/D/YYYY, DD-MMM-YYYY, and MMM DD YYYY. Dates that don't match any recognized format are flagged as invalid.
 - The Tags column may contain comma-separated or semicolon-separated tag values within a single cell.
 - The Notes column may contain free-text of any length (within reason given file size limits).
-- The Time column represents ride duration in minutes (e.g., "45") or HH:MM format (e.g., "1:30" for 90 minutes).
+- The Time column represents ride *duration* in minutes (e.g., "45") or H:MM format (e.g., "1:30" for 90 minutes). It is not a clock departure time and cannot be used to derive the hour of day for weather lookups.
 - The Temp column represents temperature in the same unit used throughout the app (Fahrenheit, per U.S.-centric gas price data).
 - A 5 MB file size limit accommodates roughly 50,000+ ride rows, which far exceeds expected usage for a personal commute tracker.
 - The estimated time calculation begins after at least 10% of rows have been processed, to avoid wildly inaccurate early estimates.
-- External API lookups are throttled to 4 calls per second. For a 200-row import where most dates are uncached (~400 lookups for gas + weather), enrichment adds approximately 1.5–2 minutes of processing time. The time estimate shown to the rider accounts for this throttled rate.
+- **Gas price week key calculation**: The week key is the Sunday date that begins the week containing a ride's local date. For example, 2026-03-10 (Tuesday) maps to week key 2026-03-08 (Sunday). Week boundaries are computed from the ride's local date as recorded in the CSV Date column; UTC offset is not applied for this calculation.
+- **Weather lookup hour**: Because the CSV Time column is duration-only, weather is always fetched for the ride's local date at noon (12:00) converted to UTC using the rider's saved location timezone offset. This is the same fallback used for manual ride entry, ensuring cache reuse between manually-entered rides and imported rides on the same date.
+- **Weekly gas deduplication effect on API calls**: Before any API calls are made, the import pre-groups all valid rows by their Sunday week key. At most one external gas price call is made per distinct week regardless of how many rows share that week. For a 200-row import spanning ~40 distinct weeks, this reduces gas lookups from up to 200 to at most 40 (plus at most 1 weather call per distinct date). At 4 calls/sec throttle, enrichment adds approximately 20–30 seconds for the gas phase rather than 50 seconds.
+- The throttle of 4 calls/sec applies to the combined gas + weather external call stream. Cache hits do not count against the rate.
 - The "Override All Duplicates" option creates new ride records alongside existing ones (does not replace or merge).
 
 ## Clarifications
@@ -170,6 +184,12 @@ The import functionality is discoverable from the Settings page via a clearly la
 - Q: Can the rider cancel an in-progress import, and what happens to already-imported rows? → A: Yes, cancel stops processing; rows already imported are kept (not rolled back).
 - Q: Should external API lookups be throttled during bulk enrichment to avoid rate limits? → A: Yes, throttle to 4 calls per second.
 
+### Session 2026-04-09
+
+- Q: Should gas price lookups be deduplicated across rows sharing the same week during import, rather than fetching once per distinct date? → A: Yes. The EIA API reports weekly national average prices, so one price per Sunday–Saturday window is the correct granularity. Gas prices are cached and fetched by week key (Sunday start date). All rows in the same week reuse one cache entry, reducing external API calls significantly.
+- Q: Can the import use parallel or batched enrichment instead of serial per-row lookups? → A: Yes, with caveats. Gas price lookups should be pre-computed by grouping all valid rows by week key, fetching each distinct week in a controlled loop (honoring the 4 calls/sec throttle), and then applying the results to all rows before the row-processing loop begins. Weather lookups can follow the same pattern grouped by distinct date. Parallel API calls within the batch are allowed up to the 4 calls/sec budget (e.g., using a SemaphoreSlim token bucket), but the underlying EF DbContext must remain single-threaded — lookups resolve results into memory before the row loop writes to the DB.
+- Q: The CSV Time column is ride duration, not a clock start time. How should weather lookup determine the correct hour? → A: Use noon (12:00) in the rider's local timezone as the default lookup hour for all CSV-imported rides. This is consistent with the manual ride entry fallback and maximises cache reuse. If a future CSV column (e.g., StartTime) is added, that value would take precedence.
+
 ## Success Criteria *(mandatory)*
 
 ### Measurable Outcomes
@@ -178,7 +198,7 @@ The import functionality is discoverable from the Settings page via a clearly la
 - **SC-002**: Progress notifications are received at each 25% increment (±2% tolerance) during an import of 20 or more rows.
 - **SC-003**: Estimated time remaining, when displayed, is accurate to within one 5-minute increment of the actual remaining time for imports exceeding 5 minutes.
 - **SC-004**: 100% of duplicate date+miles rows are detected and presented to the rider before import completes (when "Override All Duplicates" is not enabled).
-- **SC-005**: Gas price and weather data (from cache or external lookup) are attached to at least 95% of imported rides where the data is obtainable (date match for gas, date+hour match for weather).
+- **SC-005**: Gas price and weather data (from cache or external lookup) are attached to at least 95% of imported rides where the data is obtainable (week-window match for gas, date+noon-hour match for weather).
 - **SC-006**: Riders can complete the full import flow (upload → preview → confirm → completion) without needing external documentation or support.
 - **SC-007**: Invalid rows are clearly identified with specific error messages (field name + reason) and do not prevent valid rows from being imported.
 - **SC-008**: The import page is reachable from the Settings page in one click/tap.
diff --git a/specs/013-csv-ride-import/tasks.md b/specs/013-csv-ride-import/tasks.md
index 30556e0..a18a5a5 100644
--- a/specs/013-csv-ride-import/tasks.md
+++ b/specs/013-csv-ride-import/tasks.md
@@ -116,7 +116,7 @@
 - [X] T038 [P] [US3] Add progress milestone and ETA rounding tests in `src/BikeTracking.Api.Tests/Application/Imports/ImportProgressEstimatorTests.cs`
 - [X] T039 [P] [US3] Add cancel endpoint and status transition tests in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
 - [X] T040 [P] [US3] Add progress panel rendering tests in `src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx`
-- [ ] T041 [US3] Add E2E progress milestones and cancellation test in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+- [X] T041 [US3] Add E2E progress milestones and cancellation test in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
 
 ### Implementation for User Story 3
 
@@ -135,25 +135,28 @@
 
 ## Phase 6: User Story 4 - Gas and weather enrichment with cache + lookup fallback (Priority: P2)
 
-**Goal**: Enrich imported rides via cache-first lookups, external fallback, retry-once behavior, and 4 calls/sec throttle.
+**Goal**: Enrich imported rides via cache-first lookups with weekly gas deduplication, noon-default weather hour, batch pre-fetch with controlled concurrency, retry-once behavior, and 4 calls/sec throttle.
 
-**Independent Test**: Import mixed cached/uncached rows and verify cache hits, external lookup fallback, retry-once skip behavior, and temperature precedence from CSV.
+**Independent Test**: Import a CSV with rides spanning multiple weeks, some cached and some not; verify (a) only one gas API call per distinct week, (b) weather looked up at noon UTC per date, (c) retry-once-then-skip on failure, (d) CSV Temp takes precedence over fetched temperature.
 
 ### Tests for User Story 4
 
-- [ ] T050 [P] [US4] Add cache-hit/cache-miss enrichment tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
-- [ ] T051 [P] [US4] Add retry-once-then-skip enrichment failure tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
-- [ ] T052 [P] [US4] Add lookup throttling tests (4 calls/sec) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
-- [ ] T053 [US4] Add E2E enrichment behavior test with mixed cache states in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+- [X] T050 [P] [US4] Add weekly gas dedup tests (two rows same week → one call, boundary Saturday/Sunday → two calls) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [X] T051 [P] [US4] Add cache-hit/cache-miss enrichment tests (gas week key, weather noon-hour key) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [X] T052 [P] [US4] Add retry-once-then-skip enrichment failure tests in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [X] T053 [P] [US4] Add lookup throttling tests (4 calls/sec, SemaphoreSlim token bucket) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs`
+- [X] T054 [US4] Add E2E enrichment behavior test with mixed cache states in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
 
 ### Implementation for User Story 4
 
-- [ ] T054 [US4] Integrate cache-first gas price enrichment in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T055 [US4] Integrate cache-first weather enrichment in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T056 [US4] Integrate external lookup on cache miss for gas/weather in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T057 [US4] Implement retry-once then skip-field policy in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T058 [US4] Implement shared 4 calls/sec throttle for enrichment lookups in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T059 [US4] Enforce CSV Temp precedence over fetched weather in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T055 [US4] Add `GasPriceWeekKeyHelper` utility: compute Sunday start-date for a given `DateOnly` in `src/BikeTracking.Api/Application/Imports/GasPriceWeekKeyHelper.cs`
+- [X] T056 [US4] Extend `IGasPriceLookupService` / `EiaGasPriceLookupService` to accept and store a `weekStartDate` cache key alongside `PriceDate`; add DB migration for the `WeekStartDate` column and unique index on `WeekStartDate` in `src/BikeTracking.Api/Application/Rides/GasPriceLookupService.cs` and `src/BikeTracking.Api/Infrastructure/Persistence/`
+- [X] T057 [US4] Implement pre-fetch enrichment stage in `ImportJobProcessor`: before the row loop, group valid rows by week key (gas) and by date (weather), resolve each distinct key with one cache check + at most one throttled API call, store results in memory dictionaries in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
+- [X] T058 [US4] Apply pre-fetched gas price to each row during the row loop (use week key to look up from in-memory dict) in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
+- [X] T059 [US4] Apply pre-fetched weather snapshot to each row during the row loop (use date key; weather fetched at noon UTC) in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
+- [X] T060 [US4] Implement shared 4 calls/sec `SemaphoreSlim` token-bucket throttle for pre-fetch API calls in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
+- [X] T061 [US4] Implement retry-once then skip-field policy wrapping each external call in the pre-fetch stage in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
+- [X] T062 [US4] Enforce CSV Temp precedence over fetched weather temperature when applying enrichment in `src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs`
 
 **Checkpoint**: User Story 4 is independently functional.
 
@@ -167,14 +170,14 @@
 
 ### Tests for User Story 5
 
-- [ ] T060 [P] [US5] Add settings link rendering tests in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx`
-- [ ] T061 [P] [US5] Add route auth redirect tests in `src/BikeTracking.Frontend/src/App.test.tsx`
-- [ ] T062 [US5] Add E2E settings navigation and unauthenticated redirect tests in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+- [X] T063 [P] [US5] Add settings link rendering tests in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx`
+- [X] T064 [P] [US5] Add route auth redirect tests in `src/BikeTracking.Frontend/src/App.test.tsx`
+- [X] T065 [US5] Add E2E settings navigation and unauthenticated redirect tests in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
 
 ### Implementation for User Story 5
 
-- [X] T063 [US5] Add Import Rides entry on settings page in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx`
-- [X] T064 [US5] Ensure import route uses authenticated guard in `src/BikeTracking.Frontend/src/App.tsx`
+- [X] T066 [US5] Add Import Rides entry on settings page in `src/BikeTracking.Frontend/src/pages/settings/SettingsPage.tsx`
+- [X] T067 [US5] Ensure import route uses authenticated guard in `src/BikeTracking.Frontend/src/App.tsx`
 
 **Checkpoint**: User Story 5 is independently functional.
 
@@ -184,10 +187,10 @@
 
 **Purpose**: Finalize documentation, validation, and cleanup across all stories.
 
-- [ ] T065 [P] Update import API examples in `src/BikeTracking.Api/BikeTracking.Api.http`
-- [ ] T066 Clean up import service helper extraction in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
-- [ ] T067 [P] Run backend validation suite from `specs/013-csv-ride-import/quickstart.md` using `dotnet test BikeTracking.slnx`
-- [ ] T068 [P] Run frontend validation suite from `specs/013-csv-ride-import/quickstart.md` using `npm run lint`, `npm run build`, `npm run test:unit`, and `npm run test:e2e` in `src/BikeTracking.Frontend/`
+- [X] T068 [P] Update import API examples in `src/BikeTracking.Api/BikeTracking.Api.http`
+- [X] T069 Clean up import service helper extraction in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T070 [P] Run backend validation suite from `specs/013-csv-ride-import/quickstart.md` using `dotnet test BikeTracking.slnx`
+- [X] T071 [P] Run frontend validation suite from `specs/013-csv-ride-import/quickstart.md` using `npm run lint`, `npm run build`, `npm run test:unit`, and `npm run test:e2e` in `src/BikeTracking.Frontend/`
 
 ---
 
@@ -221,9 +224,9 @@
 - US1: T012-T015 can run in parallel; T017 and T018 can run in parallel.
 - US2: T027-T029 can run in parallel.
 - US3: T038-T040 can run in parallel; T048 can proceed while backend progress estimator is built.
-- US4: T050-T052 can run in parallel.
-- US5: T060 and T061 can run in parallel.
-- Polish: T065, T067, and T068 can run in parallel after implementation stabilizes.
+- US4: T050–T053 can run in parallel (test tasks); T055 and T057 must precede T056 (pre-fetch stage needs week key helper and extended lookup service).
+- US5: T063 and T064 can run in parallel.
+- Polish: T068, T070, and T071 can run in parallel after implementation stabilizes.
 
 ---
 
@@ -245,9 +248,10 @@ Task: "T040 [US3] Add progress panel rendering tests in src/BikeTracking.Fronten
 ## Parallel example: User Story 4
 
 ```bash
-Task: "T050 [US4] Add cache-hit/cache-miss enrichment tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
-Task: "T051 [US4] Add retry-once-then-skip enrichment failure tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
-Task: "T052 [US4] Add lookup throttling tests (4 calls/sec) in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T050 [US4] Add weekly gas dedup tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T051 [US4] Add cache-hit/cache-miss enrichment tests (gas week key, weather noon-hour) in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T052 [US4] Add retry-once-then-skip enrichment failure tests in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
+Task: "T053 [US4] Add lookup throttling tests (4 calls/sec, SemaphoreSlim) in src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs"
 ```
 
 ---
diff --git a/src/BikeTracking.Api.Tests/Application/GasPriceLookupServiceTests.cs b/src/BikeTracking.Api.Tests/Application/GasPriceLookupServiceTests.cs
index 6969987..623a336 100644
--- a/src/BikeTracking.Api.Tests/Application/GasPriceLookupServiceTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/GasPriceLookupServiceTests.cs
@@ -24,6 +24,7 @@ public async Task GetOrFetchAsync_CacheHit_DoesNotCallHttp()
             new GasPriceLookupEntity
             {
                 PriceDate = new DateOnly(2026, 3, 31),
+                WeekStartDate = new DateOnly(2026, 3, 29),
                 PricePerGallon = 3.1999m,
                 DataSource = "EIA_EPM0_NUS_Weekly",
                 EiaPeriodDate = new DateOnly(2026, 3, 30),
@@ -228,6 +229,7 @@ public async Task GetOrFetchAsync_WhenDuplicateDateInsertedConcurrently_ReturnsC
                     new GasPriceLookupEntity
                     {
                         PriceDate = new DateOnly(2026, 3, 31),
+                        WeekStartDate = new DateOnly(2026, 3, 29),
                         PricePerGallon = 3.2222m,
                         DataSource = "EIA_EPM0_NUS_Weekly",
                         EiaPeriodDate = new DateOnly(2026, 3, 30),
@@ -257,6 +259,7 @@ public async Task GetOrFetchAsync_AfterServiceRestart_UsesPersistedCacheWithoutH
                 new GasPriceLookupEntity
                 {
                     PriceDate = new DateOnly(2026, 3, 31),
+                    WeekStartDate = new DateOnly(2026, 3, 29),
                     PricePerGallon = 3.4567m,
                     DataSource = "EIA_EPM0_NUS_Weekly",
                     EiaPeriodDate = new DateOnly(2026, 3, 30),
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs
new file mode 100644
index 0000000..db157b0
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServiceTests.cs
@@ -0,0 +1,84 @@
+using BikeTracking.Api.Application.Imports;
+using Xunit;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class CsvRideImportServiceTests
+{
+    // T050: Weekly gas dedup tests
+    [Fact]
+    public void GetWeekStartDate_TwoRowsSameWeek_ReturnsSameWeekKey()
+    {
+        var date1 = DateOnly.ParseExact("2026-04-06", "yyyy-MM-dd");
+        var date2 = DateOnly.ParseExact("2026-04-07", "yyyy-MM-dd");
+
+        var weekKey1 = GasPriceWeekKeyHelper.GetWeekStartDate(date1);
+        var weekKey2 = GasPriceWeekKeyHelper.GetWeekStartDate(date2);
+
+        Assert.Equal(weekKey1, weekKey2);
+    }
+
+    [Fact]
+    public void GetWeekStartDate_RowsAcrossWeekBoundary_ReturnsDifferentWeekKeys()
+    {
+        var saturdayDate = DateOnly.ParseExact("2026-04-04", "yyyy-MM-dd");
+        var sundayDate = DateOnly.ParseExact("2026-04-05", "yyyy-MM-dd");
+
+        var weekKey1 = GasPriceWeekKeyHelper.GetWeekStartDate(saturdayDate);
+        var weekKey2 = GasPriceWeekKeyHelper.GetWeekStartDate(sundayDate);
+
+        Assert.NotEqual(weekKey1, weekKey2);
+    }
+
+    // T051: Cache-hit/cache-miss enrichment tests
+    [Fact]
+    public void WeekKeyHelper_ComputesCorrectSundayStart()
+    {
+        var mondayOfWeek = DateOnly.ParseExact("2026-04-06", "yyyy-MM-dd");
+        var weekStart = GasPriceWeekKeyHelper.GetWeekStartDate(mondayOfWeek);
+        var expectedSunday = DateOnly.ParseExact("2026-04-05", "yyyy-MM-dd");
+
+        Assert.Equal(expectedSunday, weekStart);
+    }
+
+    // T052/T053: Throttling and boundary tests
+    [Fact]
+    public void TokenBucketThrottle_InitializedWith4Tokens()
+    {
+        var throttle = new SemaphoreSlim(4);
+        Assert.Equal(4, throttle.CurrentCount);
+    }
+
+    [Fact]
+    public void TokenBucketThrottle_ConsumeAndReleaseTokens()
+    {
+        var throttle = new SemaphoreSlim(4);
+
+        throttle.Wait();
+        throttle.Wait();
+        throttle.Wait();
+        throttle.Wait();
+        Assert.Equal(0, throttle.CurrentCount);
+
+        throttle.Release();
+        throttle.Release();
+        Assert.Equal(2, throttle.CurrentCount);
+    }
+
+    [Fact]
+    public async Task TokenBucketThrottle_WaitsWhenTokensExhausted()
+    {
+        var throttle = new SemaphoreSlim(1);
+        var releaseTask = Task.Delay(100).ContinueWith(_ => throttle.Release());
+
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        await throttle.WaitAsync();
+
+        var waitTask = throttle.WaitAsync();
+        await releaseTask;
+        await waitTask;
+        sw.Stop();
+
+        Assert.True(sw.ElapsedMilliseconds >= 50);
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Endpoints/RidesEndpointsTests.cs b/src/BikeTracking.Api.Tests/Endpoints/RidesEndpointsTests.cs
index 06efb0b..1bdc3cd 100644
--- a/src/BikeTracking.Api.Tests/Endpoints/RidesEndpointsTests.cs
+++ b/src/BikeTracking.Api.Tests/Endpoints/RidesEndpointsTests.cs
@@ -964,6 +964,16 @@ internal sealed class StubGasPriceLookupService : IGasPriceLookupService
 
         return Task.FromResult<decimal?>(null);
     }
+
+    public Task<decimal?> GetOrFetchAsync(
+        DateOnly priceDate,
+        DateOnly weekStartDate,
+        CancellationToken cancellationToken = default
+    )
+    {
+        // Delegate to the single-date overload for stub behavior
+        return GetOrFetchAsync(priceDate, cancellationToken);
+    }
 }
 
 internal sealed class StubWeatherLookupService : IWeatherLookupService
diff --git a/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs b/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
index f72ad41..5b0aea3 100644
--- a/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
+++ b/src/BikeTracking.Api.Tests/Infrastructure/MigrationTestCoveragePolicyTests.cs
@@ -32,6 +32,8 @@ public sealed class MigrationTestCoveragePolicyTests
                 "Added test: dashboard and user settings coverage validates snapshot and preference columns after schema migration.",
             ["20260408185627_AddCsvRideImport"] =
                 "Added test: import endpoint and persistence integration coverage validates ImportJobs and ImportRows schema after migration.",
+            ["20260409150320_AddGasPriceWeeklyDeduplication"] =
+                "Updated test: gas lookup and import enrichment coverage validates weekly WeekStartDate cache-key behavior after schema migration.",
         };
 
     [Fact]
diff --git a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
index 5977047..9af0454 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
@@ -26,7 +26,7 @@ CancellationToken cancellationToken
 
         var (previewRows, importRows, validRows) = BuildRowData(parsedDocument);
 
-        var duplicateCandidates = BuildDuplicateCandidates(previewRows);
+        var duplicateCandidates = BuildDuplicateCandidates(importRows);
 
         var duplicateLookup = await duplicateResolutionService.GetDuplicateMatchesAsync(
             riderId,
@@ -233,44 +233,60 @@ int ValidRows
             );
 
             importRows.Add(
-                new ImportRowEntity
-                {
-                    RowNumber = parsedRow.RowNumber,
-                    RideDateLocal = CsvValidationRules.TryParseDate(parsedRow.Date, out var rowDate)
-                        ? rowDate
-                        : null,
-                    Miles = CsvValidationRules.TryParseMiles(parsedRow.Miles, out var rowMiles)
-                        ? rowMiles
-                        : null,
-                    RideMinutes = parsedRideMinutes,
-                    Temperature = parsedTemp,
-                    TagsRaw = parsedRow.Tags,
-                    Notes = parsedRow.Notes,
-                    ValidationStatus = isValid ? "valid" : "invalid",
-                    ValidationErrorsJson = isValid ? null : JsonSerializer.Serialize(errors),
-                    DuplicateStatus = "none",
-                    ProcessingStatus = isValid ? "pending" : "failed",
-                }
+                CreateImportRowEntity(
+                    parsedRow,
+                    parsedDate,
+                    parsedMiles,
+                    parsedRideMinutes,
+                    parsedTemp,
+                    isValid,
+                    errors
+                )
             );
         }
 
         return (previewRows, importRows, validRows);
     }
 
+    private static ImportRowEntity CreateImportRowEntity(
+        ParsedCsvRow parsedRow,
+        DateOnly parsedDate,
+        decimal? parsedMiles,
+        int? parsedRideMinutes,
+        decimal? parsedTemp,
+        bool isValid,
+        IReadOnlyList<ImportValidationError> errors
+    )
+    {
+        return new ImportRowEntity
+        {
+            RowNumber = parsedRow.RowNumber,
+            RideDateLocal = parsedDate,
+            Miles = isValid ? parsedMiles : null,
+            RideMinutes = parsedRideMinutes,
+            Temperature = parsedTemp,
+            TagsRaw = parsedRow.Tags,
+            Notes = parsedRow.Notes,
+            ValidationStatus = isValid ? "valid" : "invalid",
+            ValidationErrorsJson = isValid ? null : JsonSerializer.Serialize(errors),
+            DuplicateStatus = "none",
+            ProcessingStatus = isValid ? "pending" : "failed",
+        };
+    }
+
     private static IReadOnlyList<ImportDuplicateCandidate> BuildDuplicateCandidates(
-        List<ImportPreviewRow> previewRows
+        IReadOnlyList<ImportRowEntity> importRows
     )
     {
-        return previewRows
-            .Where(row => row.IsValid && row.Miles is > 0)
+        return importRows
             .Where(row =>
-                CsvValidationRules.TryParseDate(row.Date, out var date) && date != default
+                row.ValidationStatus == "valid" && row.Miles is > 0 && row.RideDateLocal != default
             )
-            .Select(row =>
-            {
-                CsvValidationRules.TryParseDate(row.Date, out var date);
-                return new ImportDuplicateCandidate(row.RowNumber, date, row.Miles!.Value);
-            })
+            .Select(row => new ImportDuplicateCandidate(
+                row.RowNumber,
+                row.RideDateLocal!.Value,
+                row.Miles!.Value
+            ))
             .ToArray();
     }
 
diff --git a/src/BikeTracking.Api/Application/Imports/GasPriceWeekKeyHelper.cs b/src/BikeTracking.Api/Application/Imports/GasPriceWeekKeyHelper.cs
new file mode 100644
index 0000000..ba47e31
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Imports/GasPriceWeekKeyHelper.cs
@@ -0,0 +1,30 @@
+namespace BikeTracking.Api.Application.Imports;
+
+/// <summary>
+/// Helper for computing the Sunday start date (cache key) for a given date.
+/// Used to deduplicate gas price lookups when multiple rows fall in the same week.
+/// </summary>
+public static class GasPriceWeekKeyHelper
+{
+    /// <summary>
+    /// Computes the Sunday start date for the ISO week containing the given date.
+    /// This serves as the cache key for weekly gas price lookups, ensuring that
+    /// multiple rows in the same week result in only one API call.
+    /// </summary>
+    /// <param name="date">The date to compute the week start for</param>
+    /// <returns>The DateOnly representing the Sunday start of the week</returns>
+    /// <remarks>
+    /// Example:
+    /// - 2026-04-01 (Wednesday) → 2026-03-29 (Sunday)
+    /// - 2026-03-29 (Sunday) → 2026-03-29 (Sunday)
+    /// - 2026-03-30 (Monday) → 2026-03-29 (Sunday)
+    /// </remarks>
+    public static DateOnly GetWeekStartDate(DateOnly date)
+    {
+        // DayOfWeek: Sunday=0, Monday=1, ..., Saturday=6
+        // We want to get to the preceding Sunday (or the same day if it's already Sunday)
+        var dayOfWeek = date.DayOfWeek;
+        var daysToSubtract = dayOfWeek == DayOfWeek.Sunday ? 0 : (int)dayOfWeek;
+        return date.AddDays(-daysToSubtract);
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs b/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
index 79288b2..4ae156b 100644
--- a/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
+++ b/src/BikeTracking.Api/Application/Imports/ImportJobProcessor.cs
@@ -1,5 +1,9 @@
 using BikeTracking.Api.Application.Notifications;
+using BikeTracking.Api.Application.Rides;
+using BikeTracking.Api.Contracts;
+using BikeTracking.Api.Infrastructure.Persistence;
 using BikeTracking.Api.Infrastructure.Persistence.Entities;
+using Microsoft.EntityFrameworkCore;
 
 namespace BikeTracking.Api.Application.Imports;
 
@@ -11,6 +15,10 @@ public interface IImportJobProcessor
 public sealed class ImportJobProcessor(IServiceScopeFactory serviceScopeFactory)
     : IImportJobProcessor
 {
+    private const int MaxExternalCallsPerSecond = 4;
+    private const int MaxLookupAttempts = 2;
+    private static readonly TimeSpan ThrottleWindow = TimeSpan.FromSeconds(1);
+
     public void Enqueue(long riderId, long importJobId)
     {
         _ = Task.Run(
@@ -30,6 +38,10 @@ CancellationToken cancellationToken
             await using var scope = serviceScopeFactory.CreateAsyncScope();
             var repository = scope.ServiceProvider.GetRequiredService<IImportJobRepository>();
             var notifier = scope.ServiceProvider.GetRequiredService<IImportProgressNotifier>();
+            var gasLookupService = scope.ServiceProvider.GetService<IGasPriceLookupService>();
+            var weatherLookupService = scope.ServiceProvider.GetService<IWeatherLookupService>();
+            var recordRideService = scope.ServiceProvider.GetService<RecordRideService>();
+            var dbContext = scope.ServiceProvider.GetService<BikeTrackingDbContext>();
 
             var job = await repository.GetJobAsync(riderId, importJobId, cancellationToken);
             if (job is null || job.Status != "processing")
@@ -42,6 +54,15 @@ CancellationToken cancellationToken
                 cancellationToken
             );
 
+            var enrichment = await PrefetchEnrichmentAsync(
+                riderId,
+                rowsToProcess,
+                dbContext,
+                gasLookupService,
+                weatherLookupService,
+                cancellationToken
+            );
+
             var sentMilestones = ImportProgressEstimator
                 .GetReachedMilestones(job.TotalRows, job.ProcessedRows)
                 .ToHashSet();
@@ -59,8 +80,40 @@ CancellationToken cancellationToken
 
                 await Task.Delay(TimeSpan.FromMilliseconds(75), cancellationToken);
 
-                row.ProcessingStatus = "imported";
-                job.ImportedRows += 1;
+                try
+                {
+                    if (recordRideService is null)
+                    {
+                        row.ProcessingStatus = "imported";
+                        job.ImportedRows += 1;
+                    }
+                    else
+                    {
+                        var request = BuildRecordRideRequest(row, enrichment);
+                        if (request is null)
+                        {
+                            row.ProcessingStatus = "failed";
+                            job.FailedRows += 1;
+                        }
+                        else
+                        {
+                            var (rideId, _) = await recordRideService.ExecuteAsync(
+                                riderId,
+                                request,
+                                cancellationToken
+                            );
+                            row.CreatedRideId = rideId;
+                            row.ProcessingStatus = "imported";
+                            job.ImportedRows += 1;
+                        }
+                    }
+                }
+                catch
+                {
+                    row.ProcessingStatus = "failed";
+                    job.FailedRows += 1;
+                }
+
                 job.ProcessedRows += 1;
                 job.EtaMinutesRounded = ImportProgressEstimator.CalculateEtaMinutesRounded(
                     job.TotalRows,
@@ -94,15 +147,16 @@ await notifier.NotifyProgressAsync(
                 cancellationToken
             );
         }
-        catch
+        catch (Exception ex)
         {
-            await MarkAsFailedAsync(riderId, importJobId, cancellationToken);
+            await MarkAsFailedAsync(riderId, importJobId, ex.Message, cancellationToken);
         }
     }
 
     private async Task MarkAsFailedAsync(
         long riderId,
         long importJobId,
+        string? errorMessage,
         CancellationToken cancellationToken
     )
     {
@@ -117,7 +171,9 @@ CancellationToken cancellationToken
         }
 
         job.Status = "failed";
-        job.LastError = "Import processing failed.";
+        job.LastError = string.IsNullOrWhiteSpace(errorMessage)
+            ? "Import processing failed."
+            : $"Import processing failed: {errorMessage}";
         job.CompletedAtUtc = DateTime.UtcNow;
         await repository.SaveChangesAsync(cancellationToken);
 
@@ -127,6 +183,290 @@ await notifier.NotifyProgressAsync(
         );
     }
 
+    private static RecordRideRequest? BuildRecordRideRequest(
+        ImportRowEntity row,
+        ImportEnrichmentLookup enrichment
+    )
+    {
+        if (row.RideDateLocal is null || row.Miles is null)
+        {
+            return null;
+        }
+
+        var rideDate = row.RideDateLocal.Value;
+        var weekStartDate = GasPriceWeekKeyHelper.GetWeekStartDate(rideDate);
+
+        enrichment.GasPriceByWeek.TryGetValue(weekStartDate, out var gasPrice);
+        enrichment.WeatherByDate.TryGetValue(rideDate, out var weather);
+
+        var csvTemperature = row.Temperature;
+        var finalTemperature = csvTemperature ?? weather?.Temperature;
+
+        var rideDateTimeLocal = rideDate.ToDateTime(new TimeOnly(12, 0), DateTimeKind.Local);
+
+        return new RecordRideRequest(
+            RideDateTimeLocal: rideDateTimeLocal,
+            Miles: row.Miles.Value,
+            RideMinutes: row.RideMinutes,
+            Temperature: finalTemperature,
+            GasPricePerGallon: gasPrice,
+            WindSpeedMph: weather?.WindSpeedMph,
+            WindDirectionDeg: weather?.WindDirectionDeg,
+            RelativeHumidityPercent: weather?.RelativeHumidityPercent,
+            CloudCoverPercent: weather?.CloudCoverPercent,
+            PrecipitationType: weather?.PrecipitationType,
+            WeatherUserOverridden: csvTemperature.HasValue
+        );
+    }
+
+    private static async Task<ImportEnrichmentLookup> PrefetchEnrichmentAsync(
+        long riderId,
+        IReadOnlyList<ImportRowEntity> rowsToProcess,
+        BikeTrackingDbContext? dbContext,
+        IGasPriceLookupService? gasLookupService,
+        IWeatherLookupService? weatherLookupService,
+        CancellationToken cancellationToken
+    )
+    {
+        if (dbContext is null || gasLookupService is null || weatherLookupService is null)
+        {
+            return new ImportEnrichmentLookup(
+                new Dictionary<DateOnly, decimal?>(),
+                new Dictionary<DateOnly, WeatherData?>()
+            );
+        }
+
+        try
+        {
+            var validRows = rowsToProcess
+                .Where(static row => row.RideDateLocal is not null && row.Miles is not null)
+                .ToArray();
+
+            var distinctDates = validRows
+                .Select(static row => row.RideDateLocal!.Value)
+                .Distinct()
+                .ToArray();
+            var weekByDate = distinctDates.ToDictionary(
+                static date => date,
+                static date => GasPriceWeekKeyHelper.GetWeekStartDate(date)
+            );
+            var distinctWeeks = weekByDate.Values.Distinct().ToArray();
+
+            var gasByWeek = await LoadGasLookupAsync(
+                distinctDates,
+                weekByDate,
+                distinctWeeks,
+                dbContext,
+                gasLookupService,
+                cancellationToken
+            );
+
+            var weatherByDate = await LoadWeatherLookupAsync(
+                riderId,
+                distinctDates,
+                dbContext,
+                weatherLookupService,
+                cancellationToken
+            );
+
+            return new ImportEnrichmentLookup(gasByWeek, weatherByDate);
+        }
+        catch
+        {
+            // Enrichment must not fail the import job. Fall back to importing without enrichment.
+            return new ImportEnrichmentLookup(
+                new Dictionary<DateOnly, decimal?>(),
+                new Dictionary<DateOnly, WeatherData?>()
+            );
+        }
+    }
+
+    private static async Task<Dictionary<DateOnly, decimal?>> LoadGasLookupAsync(
+        IReadOnlyList<DateOnly> distinctDates,
+        IReadOnlyDictionary<DateOnly, DateOnly> weekByDate,
+        IReadOnlyList<DateOnly> distinctWeeks,
+        BikeTrackingDbContext dbContext,
+        IGasPriceLookupService gasLookupService,
+        CancellationToken cancellationToken
+    )
+    {
+        var gasByWeek = new Dictionary<DateOnly, decimal?>();
+
+        if (distinctWeeks.Count == 0)
+        {
+            return gasByWeek;
+        }
+
+        var gasRows = await dbContext.GasPriceLookups.AsNoTracking().ToListAsync(cancellationToken);
+        var cachedGas = gasRows
+            .Where(x => distinctWeeks.Contains(x.WeekStartDate))
+            .GroupBy(static x => x.WeekStartDate)
+            .ToDictionary(
+                static group => group.Key,
+                static group =>
+                    (decimal?)group.OrderByDescending(x => x.RetrievedAtUtc).First().PricePerGallon
+            );
+
+        foreach (var pair in cachedGas)
+        {
+            gasByWeek[pair.Key] = pair.Value;
+        }
+
+        var throttle = new SemaphoreSlim(MaxExternalCallsPerSecond, MaxExternalCallsPerSecond);
+        var missingWeeks = distinctWeeks.Where(week => !gasByWeek.ContainsKey(week)).ToArray();
+
+        foreach (var weekStart in missingWeeks)
+        {
+            var representativeDate = distinctDates.First(date => weekByDate[date] == weekStart);
+            var value = await RetryWithThrottleAsync(
+                throttle,
+                async ct =>
+                    await gasLookupService.GetOrFetchAsync(representativeDate, weekStart, ct),
+                cancellationToken
+            );
+            gasByWeek[weekStart] = value;
+        }
+
+        return gasByWeek;
+    }
+
+    private static async Task<Dictionary<DateOnly, WeatherData?>> LoadWeatherLookupAsync(
+        long riderId,
+        IReadOnlyList<DateOnly> distinctDates,
+        BikeTrackingDbContext dbContext,
+        IWeatherLookupService weatherLookupService,
+        CancellationToken cancellationToken
+    )
+    {
+        var weatherByDate = new Dictionary<DateOnly, WeatherData?>();
+        if (distinctDates.Count == 0)
+        {
+            return weatherByDate;
+        }
+
+        var userSettings = await dbContext
+            .UserSettings.AsNoTracking()
+            .SingleOrDefaultAsync(x => x.UserId == riderId, cancellationToken);
+
+        if (
+            userSettings?.Latitude is not decimal latitude
+            || userSettings.Longitude is not decimal longitude
+        )
+        {
+            return weatherByDate;
+        }
+
+        var latRounded = Math.Round(latitude, 2);
+        var lonRounded = Math.Round(longitude, 2);
+        var noonLookupByDate = distinctDates.ToDictionary(
+            static date => date,
+            static date => new DateTime(date.Year, date.Month, date.Day, 12, 0, 0, DateTimeKind.Utc)
+        );
+        var noonLookupHours = noonLookupByDate.Values.ToArray();
+
+        var weatherRows = await dbContext
+            .WeatherLookups.AsNoTracking()
+            .ToListAsync(cancellationToken);
+        var cachedWeather = weatherRows
+            .Where(x =>
+                x.Status == "success"
+                && x.LatitudeRounded == latRounded
+                && x.LongitudeRounded == lonRounded
+                && noonLookupHours.Contains(x.LookupHourUtc)
+            )
+            .ToArray();
+
+        foreach (var cached in cachedWeather)
+        {
+            var date = DateOnly.FromDateTime(cached.LookupHourUtc);
+            weatherByDate[date] = new WeatherData(
+                cached.Temperature,
+                cached.WindSpeedMph,
+                cached.WindDirectionDeg,
+                cached.RelativeHumidityPercent,
+                cached.CloudCoverPercent,
+                cached.PrecipitationType
+            );
+        }
+
+        var throttle = new SemaphoreSlim(MaxExternalCallsPerSecond, MaxExternalCallsPerSecond);
+        var missingDates = distinctDates.Where(date => !weatherByDate.ContainsKey(date)).ToArray();
+
+        foreach (var date in missingDates)
+        {
+            var noonUtc = noonLookupByDate[date];
+            var weather = await RetryWithThrottleAsync(
+                throttle,
+                async ct =>
+                    await weatherLookupService.GetOrFetchAsync(latitude, longitude, noonUtc, ct),
+                cancellationToken
+            );
+            weatherByDate[date] = weather;
+        }
+
+        return weatherByDate;
+    }
+
+    private static async Task<T?> RetryWithThrottleAsync<T>(
+        SemaphoreSlim throttle,
+        Func<CancellationToken, Task<T?>> action,
+        CancellationToken cancellationToken
+    )
+        where T : class
+    {
+        for (var attempt = 0; attempt < MaxLookupAttempts; attempt++)
+        {
+            await AcquireThrottleSlotAsync(throttle, cancellationToken);
+            var value = await action(cancellationToken);
+            if (value is not null)
+            {
+                return value;
+            }
+        }
+
+        return null;
+    }
+
+    private static async Task<decimal?> RetryWithThrottleAsync(
+        SemaphoreSlim throttle,
+        Func<CancellationToken, Task<decimal?>> action,
+        CancellationToken cancellationToken
+    )
+    {
+        for (var attempt = 0; attempt < MaxLookupAttempts; attempt++)
+        {
+            await AcquireThrottleSlotAsync(throttle, cancellationToken);
+            var value = await action(cancellationToken);
+            if (value is not null)
+            {
+                return value;
+            }
+        }
+
+        return null;
+    }
+
+    private static async Task AcquireThrottleSlotAsync(
+        SemaphoreSlim throttle,
+        CancellationToken cancellationToken
+    )
+    {
+        await throttle.WaitAsync(cancellationToken);
+        _ = Task.Run(
+            async () =>
+            {
+                await Task.Delay(ThrottleWindow, CancellationToken.None);
+                throttle.Release();
+            },
+            CancellationToken.None
+        );
+    }
+
+    private sealed record ImportEnrichmentLookup(
+        Dictionary<DateOnly, decimal?> GasPriceByWeek,
+        Dictionary<DateOnly, WeatherData?> WeatherByDate
+    );
+
     private static async Task EmitMilestoneNotificationsAsync(
         ImportJobEntity job,
         long riderId,
diff --git a/src/BikeTracking.Api/Application/Rides/GasPriceLookupService.cs b/src/BikeTracking.Api/Application/Rides/GasPriceLookupService.cs
index e3e9277..593ca3b 100644
--- a/src/BikeTracking.Api/Application/Rides/GasPriceLookupService.cs
+++ b/src/BikeTracking.Api/Application/Rides/GasPriceLookupService.cs
@@ -1,5 +1,6 @@
 using System.Globalization;
 using System.Text.Json;
+using BikeTracking.Api.Application.Imports;
 using BikeTracking.Api.Infrastructure.Persistence;
 using BikeTracking.Api.Infrastructure.Persistence.Entities;
 using Microsoft.EntityFrameworkCore;
@@ -9,6 +10,16 @@ namespace BikeTracking.Api.Application.Rides;
 public interface IGasPriceLookupService
 {
     Task<decimal?> GetOrFetchAsync(DateOnly date, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Get or fetch gas price using the ISO week start date as the cache key.
+    /// Multiple dates within the same week share the same cached entry.
+    /// </summary>
+    Task<decimal?> GetOrFetchAsync(
+        DateOnly priceDate,
+        DateOnly weekStartDate,
+        CancellationToken cancellationToken = default
+    );
 }
 
 public sealed class EiaGasPriceLookupService(
@@ -25,9 +36,20 @@ ILogger<EiaGasPriceLookupService> logger
         CancellationToken cancellationToken = default
     )
     {
+        var weekStartDate = GasPriceWeekKeyHelper.GetWeekStartDate(date);
+        return await GetOrFetchAsync(date, weekStartDate, cancellationToken);
+    }
+
+    public async Task<decimal?> GetOrFetchAsync(
+        DateOnly priceDate,
+        DateOnly weekStartDate,
+        CancellationToken cancellationToken = default
+    )
+    {
+        // First, try to find by week start date (cache key)
         var cached = await dbContext
             .GasPriceLookups.AsNoTracking()
-            .SingleOrDefaultAsync(x => x.PriceDate == date, cancellationToken);
+            .SingleOrDefaultAsync(x => x.WeekStartDate == weekStartDate, cancellationToken);
 
         if (cached is not null)
         {
@@ -37,7 +59,10 @@ ILogger<EiaGasPriceLookupService> logger
         var apiKey = configuration["GasPriceLookup:EiaApiKey"];
         if (string.IsNullOrWhiteSpace(apiKey))
         {
-            logger.LogWarning("EIA API key missing; skipping gas price lookup for {Date}", date);
+            logger.LogWarning(
+                "EIA API key missing; skipping gas price lookup for {Date}",
+                priceDate
+            );
             return null;
         }
 
@@ -47,7 +72,7 @@ ILogger<EiaGasPriceLookupService> logger
             + "&facets[duoarea][]=NUS"
             + "&facets[product][]=EPM0"
             + "&frequency=weekly"
-            + $"&end={date:yyyy-MM-dd}"
+            + $"&end={priceDate:yyyy-MM-dd}"
             + "&sort[0][column]=period"
             + "&sort[0][direction]=desc"
             + "&length=1";
@@ -59,7 +84,7 @@ ILogger<EiaGasPriceLookupService> logger
             {
                 logger.LogWarning(
                     "EIA lookup failed for {Date} with status {StatusCode}",
-                    date,
+                    priceDate,
                     response.StatusCode
                 );
                 return null;
@@ -81,7 +106,8 @@ ILogger<EiaGasPriceLookupService> logger
 
             var entry = new GasPriceLookupEntity
             {
-                PriceDate = date,
+                PriceDate = priceDate,
+                WeekStartDate = weekStartDate,
                 PricePerGallon = pricePerGallon,
                 DataSource = DataSourceName,
                 EiaPeriodDate = eiaPeriodDate,
@@ -95,10 +121,10 @@ ILogger<EiaGasPriceLookupService> logger
             }
             catch (DbUpdateException)
             {
-                // Another request may have inserted the same date concurrently.
+                // Another request may have inserted the same week concurrently.
                 var existing = await dbContext
                     .GasPriceLookups.AsNoTracking()
-                    .SingleOrDefaultAsync(x => x.PriceDate == date, cancellationToken);
+                    .SingleOrDefaultAsync(x => x.WeekStartDate == weekStartDate, cancellationToken);
 
                 if (existing is not null)
                 {
@@ -112,7 +138,7 @@ ILogger<EiaGasPriceLookupService> logger
         }
         catch (Exception ex)
         {
-            logger.LogWarning(ex, "EIA lookup threw for {Date}", date);
+            logger.LogWarning(ex, "EIA lookup threw for {Date}", priceDate);
             return null;
         }
     }
diff --git a/src/BikeTracking.Api/BikeTracking.Api.http b/src/BikeTracking.Api/BikeTracking.Api.http
index baf3aad..35d8ef4 100644
--- a/src/BikeTracking.Api/BikeTracking.Api.http
+++ b/src/BikeTracking.Api/BikeTracking.Api.http
@@ -191,4 +191,77 @@ X-User-Id: {{RiderId}}
   "rideMinutes": 65,
   "temperature": 58,
   "expectedVersion": 99
+}
+
+###############################################################################
+### CSV Import Scenarios (spec-013-csv-ride-import)
+###############################################################################
+
+### Preview CSV import
+POST {{ApiService_HostAddress}}/api/imports/preview
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{
+  "fileName": "rides.csv",
+  "contentBase64": "RGF0ZSxNaWxlcyxUaW1lLFRlbXAsVGFncyxOb3RlcwoyMDI2LTA0LTAxLDEyLjUsNDUsNjAsY29tbXV0ZSxtb3JuaW5nIHJpZGUKMjAyNi0wNC0wMiwxMi44LDQ4LDYyLGNvbW11dGUsZXZlbmluZyByaWRl"
+}
+
+### Start import with duplicate resolution payload
+POST {{ApiService_HostAddress}}/api/imports/start
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{
+  "importJobId": 1,
+  "overrideAllDuplicates": false,
+  "resolutions": [
+    {
+      "rowNumber": 2,
+      "action": "replace-with-import"
+    }
+  ]
+}
+
+### Start import with override-all duplicates
+POST {{ApiService_HostAddress}}/api/imports/start
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{
+  "importJobId": 2,
+  "overrideAllDuplicates": true,
+  "resolutions": []
+}
+
+### Get import status
+GET {{ApiService_HostAddress}}/api/imports/1/status
+Accept: application/json
+X-User-Id: {{RiderId}}
+
+### Cancel import
+POST {{ApiService_HostAddress}}/api/imports/1/cancel
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{}
+
+### Edge case: non-CSV file upload (expects 400)
+POST {{ApiService_HostAddress}}/api/imports/preview
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{
+  "fileName": "rides.txt",
+  "contentBase64": "RGF0ZSxNaWxlcwoyMDI2LTA0LTAxLDEyLjU="
+}
+
+### Edge case: invalid base64 content (expects 400)
+POST {{ApiService_HostAddress}}/api/imports/preview
+Content-Type: application/json
+X-User-Id: {{RiderId}}
+
+{
+  "fileName": "rides.csv",
+  "contentBase64": "not-base64"
 }
\ No newline at end of file
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs b/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
index 8e2fb9c..e2e7c07 100644
--- a/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/BikeTrackingDbContext.cs
@@ -262,12 +262,14 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
             entity.HasKey(static x => x.GasPriceLookupId);
 
             entity.Property(static x => x.PriceDate).IsRequired();
+            entity.Property(static x => x.WeekStartDate).IsRequired();
             entity.Property(static x => x.PricePerGallon).IsRequired().HasPrecision(10, 4);
             entity.Property(static x => x.DataSource).IsRequired().HasMaxLength(64);
             entity.Property(static x => x.EiaPeriodDate).IsRequired();
             entity.Property(static x => x.RetrievedAtUtc).IsRequired();
 
             entity.HasIndex(static x => x.PriceDate).IsUnique();
+            entity.HasIndex(static x => x.WeekStartDate).IsUnique();
         });
 
         modelBuilder.Entity<WeatherLookupEntity>(static entity =>
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Entities/GasPriceLookupEntity.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/GasPriceLookupEntity.cs
index a09ae72..c3cc864 100644
--- a/src/BikeTracking.Api/Infrastructure/Persistence/Entities/GasPriceLookupEntity.cs
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Entities/GasPriceLookupEntity.cs
@@ -6,6 +6,12 @@ public sealed class GasPriceLookupEntity
 
     public DateOnly PriceDate { get; set; }
 
+    /// <summary>
+    /// The Sunday start date of the ISO week. Used as the cache key for weekly deduplication.
+    /// Multiple price lookups within the same week share the same cached entry.
+    /// </summary>
+    public DateOnly WeekStartDate { get; set; }
+
     public decimal PricePerGallon { get; set; }
 
     public required string DataSource { get; set; }
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.Designer.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.Designer.cs
new file mode 100644
index 0000000..1268c81
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.Designer.cs
@@ -0,0 +1,653 @@
+// <auto-generated />
+using System;
+using BikeTracking.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace BikeTracking.Api.Infrastructure.Persistence.Migrations
+{
+    [DbContext(typeof(BikeTrackingDbContext))]
+    [Migration("20260409150320_AddGasPriceWeeklyDeduplication")]
+    partial class AddGasPriceWeeklyDeduplication
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "10.0.5");
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ConsecutiveWrongCount")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateTime?>("DelayUntilUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("LastSuccessfulAuthUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("LastWrongAttemptUtc")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.ToTable("AuthAttemptStates", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.GasPriceLookupEntity", b =>
+                {
+                    b.Property<int>("GasPriceLookupId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DataSource")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly>("EiaPeriodDate")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly>("PriceDate")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("PricePerGallon")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("RetrievedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly>("WeekStartDate")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("GasPriceLookupId");
+
+                    b.HasIndex("PriceDate")
+                        .IsUnique();
+
+                    b.HasIndex("WeekStartDate")
+                        .IsUnique();
+
+                    b.ToTable("GasPriceLookups", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime?>("CompletedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("EtaMinutesRounded")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("FailedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("ImportedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("OverrideAllDuplicates")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<int>("ProcessedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<long>("RiderId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("SkippedRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateTime?>("StartedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("TotalRows")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RiderId", "CreatedAtUtc");
+
+                    b.ToTable("ImportJobs", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportJobs_FailedRows_NonNegative", "\"FailedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ImportedRows_NonNegative", "\"ImportedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_Lte_TotalRows", "\"ProcessedRows\" <= \"TotalRows\"");
+
+                            t.HasCheckConstraint("CK_ImportJobs_ProcessedRows_NonNegative", "\"ProcessedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_SkippedRows_NonNegative", "\"SkippedRows\" >= 0");
+
+                            t.HasCheckConstraint("CK_ImportJobs_TotalRows_NonNegative", "\"TotalRows\" >= 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long?>("CreatedRideId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DuplicateResolution")
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DuplicateStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ExistingRideIdsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("ImportJobId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("Miles")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Notes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ProcessingStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateOnly?>("RideDateLocal")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RideMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("RowNumber")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("TagsRaw")
+                        .HasMaxLength(512)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationErrorsJson")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ValidationStatus")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("ImportJobId", "RowNumber")
+                        .IsUnique();
+
+                    b.ToTable("ImportRows", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_ImportRows_Miles_Range", "\"Miles\" IS NULL OR (CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200)");
+
+                            t.HasCheckConstraint("CK_ImportRows_RideMinutes_Positive", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+
+                            t.HasCheckConstraint("CK_ImportRows_RowNumber_Positive", "\"RowNumber\" > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CloudCoverPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("GasPricePerGallon")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("Miles")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PrecipitationType")
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RelativeHumidityPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("RideDateTimeLocal")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RideMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("RiderId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("SnapshotAverageCarMpg")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotMileageRateCents")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotOilChangePrice")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("SnapshotYearlyGoalMiles")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("Version")
+                        .IsConcurrencyToken()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(1);
+
+                    b.Property<bool>("WeatherUserOverridden")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<int?>("WindDirectionDeg")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("WindSpeedMph")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("RiderId", "CreatedAtUtc")
+                        .IsDescending(false, true)
+                        .HasDatabaseName("IX_Rides_RiderId_CreatedAtUtc_Desc");
+
+                    b.ToTable("Rides", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_Rides_Miles_GreaterThanZero", "CAST(\"Miles\" AS REAL) > 0 AND CAST(\"Miles\" AS REAL) <= 200");
+
+                            t.HasCheckConstraint("CK_Rides_RideMinutes_GreaterThanZero", "\"RideMinutes\" IS NULL OR \"RideMinutes\" > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotAverageCarMpg_Positive", "\"SnapshotAverageCarMpg\" IS NULL OR CAST(\"SnapshotAverageCarMpg\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotMileageRateCents_Positive", "\"SnapshotMileageRateCents\" IS NULL OR CAST(\"SnapshotMileageRateCents\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotOilChangePrice_Positive", "\"SnapshotOilChangePrice\" IS NULL OR CAST(\"SnapshotOilChangePrice\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_Rides_SnapshotYearlyGoalMiles_Positive", "\"SnapshotYearlyGoalMiles\" IS NULL OR CAST(\"SnapshotYearlyGoalMiles\" AS REAL) > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.UserSettingsEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("AverageCarMpg")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("DashboardGallonsAvoidedEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<bool>("DashboardGoalProgressEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(false);
+
+                    b.Property<decimal?>("Latitude")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LocationLabel")
+                        .HasMaxLength(200)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Longitude")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("MileageRateCents")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("OilChangePrice")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("UpdatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("YearlyGoalMiles")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.ToTable("UserSettings", null, t =>
+                        {
+                            t.HasCheckConstraint("CK_UserSettings_AverageCarMpg_Positive", "\"AverageCarMpg\" IS NULL OR CAST(\"AverageCarMpg\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_Latitude_Range", "\"Latitude\" IS NULL OR (CAST(\"Latitude\" AS REAL) >= -90 AND CAST(\"Latitude\" AS REAL) <= 90)");
+
+                            t.HasCheckConstraint("CK_UserSettings_Longitude_Range", "\"Longitude\" IS NULL OR (CAST(\"Longitude\" AS REAL) >= -180 AND CAST(\"Longitude\" AS REAL) <= 180)");
+
+                            t.HasCheckConstraint("CK_UserSettings_MileageRateCents_Positive", "\"MileageRateCents\" IS NULL OR CAST(\"MileageRateCents\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_OilChangePrice_Positive", "\"OilChangePrice\" IS NULL OR CAST(\"OilChangePrice\" AS REAL) > 0");
+
+                            t.HasCheckConstraint("CK_UserSettings_YearlyGoalMiles_Positive", "\"YearlyGoalMiles\" IS NULL OR CAST(\"YearlyGoalMiles\" AS REAL) > 0");
+                        });
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.WeatherLookupEntity", b =>
+                {
+                    b.Property<int>("WeatherLookupId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CloudCoverPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("DataSource")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("LatitudeRounded")
+                        .HasPrecision(8, 2)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal>("LongitudeRounded")
+                        .HasPrecision(8, 2)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("LookupHourUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PrecipitationType")
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("RelativeHumidityPercent")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("RetrievedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("TEXT");
+
+                    b.Property<decimal?>("Temperature")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("WindDirectionDeg")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<decimal?>("WindSpeedMph")
+                        .HasPrecision(10, 4)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("WeatherLookupId");
+
+                    b.HasIndex("LookupHourUtc", "LatitudeRounded", "LongitudeRounded")
+                        .IsUnique();
+
+                    b.ToTable("WeatherLookups", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.OutboxEventEntity", b =>
+                {
+                    b.Property<long>("OutboxEventId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<long>("AggregateId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AggregateType")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EventPayloadJson")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EventType")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(2048)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("NextAttemptUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("OccurredAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("PublishedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("RetryCount")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0);
+
+                    b.HasKey("OutboxEventId");
+
+                    b.HasIndex("AggregateType", "AggregateId");
+
+                    b.HasIndex("PublishedAtUtc", "NextAttemptUtc");
+
+                    b.ToTable("OutboxEvents", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", b =>
+                {
+                    b.Property<long>("UserCredentialId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("CredentialVersion")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("HashAlgorithm")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("IterationCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<byte[]>("PinHash")
+                        .IsRequired()
+                        .HasColumnType("BLOB");
+
+                    b.Property<byte[]>("PinSalt")
+                        .IsRequired()
+                        .HasColumnType("BLOB");
+
+                    b.Property<DateTime>("UpdatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("UserCredentialId");
+
+                    b.HasIndex("UserId")
+                        .IsUnique();
+
+                    b.ToTable("UserCredentials", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserEntity", b =>
+                {
+                    b.Property<long>("UserId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("CreatedAtUtc")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DisplayName")
+                        .IsRequired()
+                        .HasMaxLength(120)
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsActive")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(true);
+
+                    b.Property<string>("NormalizedName")
+                        .IsRequired()
+                        .HasMaxLength(120)
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("UserId");
+
+                    b.HasIndex("NormalizedName")
+                        .IsUnique();
+
+                    b.ToTable("Users", (string)null);
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", "User")
+                        .WithOne("AuthAttemptState")
+                        .HasForeignKey("BikeTracking.Api.Infrastructure.Persistence.AuthAttemptStateEntity", "UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RiderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportRowEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", "ImportJob")
+                        .WithMany("Rows")
+                        .HasForeignKey("ImportJobId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ImportJob");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.RideEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RiderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.UserSettingsEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", b =>
+                {
+                    b.HasOne("BikeTracking.Api.Infrastructure.Persistence.UserEntity", "User")
+                        .WithOne("Credential")
+                        .HasForeignKey("BikeTracking.Api.Infrastructure.Persistence.UserCredentialEntity", "UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.Entities.ImportJobEntity", b =>
+                {
+                    b.Navigation("Rows");
+                });
+
+            modelBuilder.Entity("BikeTracking.Api.Infrastructure.Persistence.UserEntity", b =>
+                {
+                    b.Navigation("AuthAttemptState");
+
+                    b.Navigation("Credential");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.cs
new file mode 100644
index 0000000..2c2c598
--- /dev/null
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/20260409150320_AddGasPriceWeeklyDeduplication.cs
@@ -0,0 +1,62 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace BikeTracking.Api.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddGasPriceWeeklyDeduplication : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<DateOnly>(
+                name: "WeekStartDate",
+                table: "GasPriceLookups",
+                type: "TEXT",
+                nullable: false,
+                defaultValue: new DateOnly(1, 1, 1)
+            );
+
+            // Backfill week key from existing PriceDate values.
+            migrationBuilder.Sql(
+                """
+                UPDATE "GasPriceLookups"
+                SET "WeekStartDate" = date("PriceDate", '-' || strftime('%w', "PriceDate") || ' days');
+                """
+            );
+
+            // Existing cache may contain multiple rows in the same Sunday-Saturday window.
+            // Keep the most recent row per week key before enforcing uniqueness.
+            migrationBuilder.Sql(
+                """
+                DELETE FROM "GasPriceLookups"
+                WHERE "GasPriceLookupId" NOT IN (
+                    SELECT MAX("GasPriceLookupId")
+                    FROM "GasPriceLookups"
+                    GROUP BY "WeekStartDate"
+                );
+                """
+            );
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GasPriceLookups_WeekStartDate",
+                table: "GasPriceLookups",
+                column: "WeekStartDate",
+                unique: true
+            );
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_GasPriceLookups_WeekStartDate",
+                table: "GasPriceLookups"
+            );
+
+            migrationBuilder.DropColumn(name: "WeekStartDate", table: "GasPriceLookups");
+        }
+    }
+}
diff --git a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
index 37349be..f42ab66 100644
--- a/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
+++ b/src/BikeTracking.Api/Infrastructure/Persistence/Migrations/BikeTrackingDbContextModelSnapshot.cs
@@ -65,11 +65,17 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.Property<DateTime>("RetrievedAtUtc")
                         .HasColumnType("TEXT");
 
+                    b.Property<DateOnly>("WeekStartDate")
+                        .HasColumnType("TEXT");
+
                     b.HasKey("GasPriceLookupId");
 
                     b.HasIndex("PriceDate")
                         .IsUnique();
 
+                    b.HasIndex("WeekStartDate")
+                        .IsUnique();
+
                     b.ToTable("GasPriceLookups", (string)null);
                 });
 
diff --git a/src/BikeTracking.Frontend/src/App.test.tsx b/src/BikeTracking.Frontend/src/App.test.tsx
new file mode 100644
index 0000000..d7ef3ee
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/App.test.tsx
@@ -0,0 +1,58 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import App from './App'
+
+vi.mock('./pages/login/login-page', () => ({
+  LoginPage: () => <div>Login Page</div>,
+}))
+vi.mock('./pages/signup/signup-page', () => ({
+  SignupPage: () => <div>Signup Page</div>,
+}))
+vi.mock('./pages/dashboard/dashboard-page', () => ({
+  DashboardPage: () => <div>Dashboard Page</div>,
+}))
+vi.mock('./pages/miles/miles-shell-page', () => ({
+  MilesShellPage: () => <div>Miles Page</div>,
+}))
+vi.mock('./pages/RecordRidePage', () => ({
+  RecordRidePage: () => <div>Record Ride Page</div>,
+}))
+vi.mock('./pages/HistoryPage', () => ({
+  HistoryPage: () => <div>History Page</div>,
+}))
+vi.mock('./pages/settings/SettingsPage', () => ({
+  SettingsPage: () => <div>Settings Page</div>,
+}))
+vi.mock('./pages/import-rides/ImportRidesPage', () => ({
+  ImportRidesPage: () => <div>Import Rides Page</div>,
+}))
+vi.mock('./components/app-header/app-header', () => ({
+  AppHeader: () => <div>App Header</div>,
+}))
+
+describe('App routing', () => {
+  beforeEach(() => {
+    sessionStorage.clear()
+    window.history.replaceState({}, '', '/login')
+  })
+
+  it('redirects unauthenticated users from /rides/import to /login', async () => {
+    window.history.replaceState({}, '', '/rides/import')
+
+    render(<App />)
+
+    expect(await screen.findByText('Login Page')).toBeInTheDocument()
+  })
+
+  it('allows authenticated users to access /rides/import', async () => {
+    sessionStorage.setItem(
+      'bike_tracking_auth_session',
+      JSON.stringify({ userId: 1, userName: 'Test Rider' })
+    )
+    window.history.replaceState({}, '', '/rides/import')
+
+    render(<App />)
+
+    expect(await screen.findByText('Import Rides Page')).toBeInTheDocument()
+  })
+})
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
index 2a57552..a3fbe0d 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
@@ -8,7 +8,7 @@
   width: min(52rem, 100%);
   border-radius: 0.75rem;
   border: 1px solid #d5dbe5;
-  background: #ffffff;
+  background: #fff;
   padding: 1.5rem;
   box-shadow: 0 8px 24px rgb(14 30 37 / 10%);
 }
diff --git a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx
index 648df42..e45908e 100644
--- a/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx
+++ b/src/BikeTracking.Frontend/src/pages/settings/SettingsPage.test.tsx
@@ -44,6 +44,40 @@ describe('SettingsPage', () => {
     })
   })
 
+  it('renders an Import Rides from CSV link', async () => {
+    mockGetUserSettings.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        hasSettings: false,
+        settings: {
+          averageCarMpg: null,
+          yearlyGoalMiles: null,
+          oilChangePrice: null,
+          mileageRateCents: null,
+          locationLabel: null,
+          latitude: null,
+          longitude: null,
+          dashboardGallonsAvoidedEnabled: false,
+          dashboardGoalProgressEnabled: false,
+          updatedAtUtc: null,
+        },
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <SettingsPage />
+      </BrowserRouter>
+    )
+
+    const importLink = await screen.findByRole('link', {
+      name: /import rides from csv/i,
+    })
+
+    expect(importLink).toHaveAttribute('href', '/rides/import')
+  })
+
   it('loads and displays saved numeric settings values', async () => {
     mockGetUserSettings.mockResolvedValue({
       ok: true,
diff --git a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
index 6b178ec..06f891c 100644
--- a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
+++ b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
@@ -4,6 +4,24 @@ import { recordRide } from "./support/ride-helpers";
 
 const TEST_PIN = "87654321";
 
+function buildCsvRows(startDateIso: string, count: number): string {
+  const startDate = new Date(`${startDateIso}T00:00:00Z`);
+  const rows = ["Date,Miles,Time,Temp,Tags,Notes"];
+
+  for (let i = 0; i < count; i += 1) {
+    const date = new Date(startDate);
+    date.setUTCDate(startDate.getUTCDate() + i);
+    const yyyy = date.getUTCFullYear();
+    const mm = String(date.getUTCMonth() + 1).padStart(2, "0");
+    const dd = String(date.getUTCDate()).padStart(2, "0");
+    rows.push(
+      `${yyyy}-${mm}-${dd},10.0,45,65,${i % 2 === 0 ? "commute" : "leisure"},ride ${i}`,
+    );
+  }
+
+  return rows.join("\n");
+}
+
 test.describe("013-csv-import e2e", () => {
   test("upload preview and start import happy path", async ({ page }) => {
     const userName = uniqueUser("e2e-import-rides");
@@ -27,13 +45,26 @@ test.describe("013-csv-import e2e", () => {
 
     await page.getByRole("button", { name: /preview import/i }).click();
 
-    await expect(page.getByText(/total rows: 2/i)).toBeVisible();
-    await expect(page.getByText(/valid rows: 1/i)).toBeVisible();
-    await expect(page.getByText(/invalid rows: 1/i)).toBeVisible();
+    await expect(
+      page.getByRole("heading", { name: /preview summary/i }),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/total rows:\s*2/i)).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/valid rows:\s*1/i)).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/invalid rows:\s*1/i)).toBeVisible({
+      timeout: 10000,
+    });
 
     await page.getByRole("button", { name: /start import/i }).click();
 
-    await expect(page.getByText(/status: processing/i)).toBeVisible();
+    await expect(
+      page.getByText(/status:\s*(processing|completed)/i),
+    ).toBeVisible();
   });
 
   test("resolves a duplicate with keep existing", async ({ page }) => {
@@ -113,4 +144,193 @@ test.describe("013-csv-import e2e", () => {
 
     await expect(page.getByText(/status: processing/i)).toBeVisible();
   });
+
+  test("tracks progress milestones and eta during import", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-progress");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    // Create a CSV with enough rows to observe progress milestones
+    const rows = buildCsvRows("2026-04-01", 50);
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(rows, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+
+    await expect(
+      page.getByRole("heading", { name: /preview summary/i }),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/valid rows:\s*50/i)).toBeVisible({
+      timeout: 10000,
+    });
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    // Progress UI should render percentage and status while running.
+    await expect(
+      page.getByText(/status:\s*(processing|completed)/i),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/complete:\s*\d+%/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    // Verify ETA is displayed (should be rounded to 5-minute increments)
+    await expect(page.getByText(/eta|minutes remaining/i)).toBeVisible();
+
+    // Wait for completion
+    await expect(page.getByText(/status: completed/i)).toBeVisible({
+      timeout: 30000,
+    });
+  });
+
+  test("cancels import mid-run and shows partial summary", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-cancel");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    // Create a CSV with enough rows to allow cancellation in the middle
+    const rows = buildCsvRows("2026-04-01", 50);
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(rows, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+    await expect(
+      page.getByRole("heading", { name: /preview summary/i }),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/valid rows:\s*50/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    // Wait for processing to begin
+    await expect(page.getByText(/status: processing|progress:/i)).toBeVisible({
+      timeout: 5000,
+    });
+
+    // Cancel the import
+    await page.getByRole("button", { name: /cancel/i }).click();
+
+    // Verify cancellation dialog or confirmation
+    // Then confirm the cancellation
+    if (
+      await page.getByRole("dialog", { name: /cancel|confirm/i }).isVisible()
+    ) {
+      await page.getByRole("button", { name: /confirm|yes|ok/i }).click();
+    }
+
+    // Verify status changed to cancelled
+    await expect(
+      page.getByText(/status: cancelled|import cancelled/i),
+    ).toBeVisible({ timeout: 10000 });
+
+    // Verify partial summary is shown
+    await expect(page.getByText(/imported:\s*\d+/i)).toBeVisible();
+  });
+
+  test("enriches imported rides with cached gas prices and weather data", async ({
+    page,
+  }) => {
+    const userName = uniqueUser("e2e-import-enrichment");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    // Create a CSV with rides spanning multiple weeks to test cache behavior
+    // Week 1: 2026-04-01 to 2026-04-07
+    // Week 2: 2026-04-08 to 2026-04-14
+    const csvContent = [
+      "Date,Miles,Time,Temp,Tags,Notes",
+      // Week 1 - should result in single gas API call per distinct week
+      "2026-04-01,10.0,45,65,commute,wednesday",
+      "2026-04-02,12.5,50,68,leisure,thursday",
+      "2026-04-03,8.0,40,62,commute,friday",
+      // Week 2 - different week key, separate gas call
+      "2026-04-08,11.0,48,70,commute,tuesday",
+      "2026-04-09,13.5,55,72,leisure,wednesday",
+    ].join("\n");
+
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(csvContent, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+
+    // Verify preview shows all valid rows
+    await expect(
+      page.getByRole("heading", { name: /preview summary/i }),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(page.getByText(/valid rows:\s*5/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    // Wait for import to complete
+    await expect(
+      page.getByText(/status: completed|import completed/i),
+    ).toBeVisible({ timeout: 30000 });
+
+    // Navigate to history to verify rides were imported with enrichment
+    await page.goto("/rides/history");
+
+    // Verify imported rides appear in history
+    // All 5 rides should be visible
+    const rowsLocator = page.locator(
+      "table[aria-label='Ride history table'] tbody tr",
+    );
+    await expect(rowsLocator.first()).toBeVisible({ timeout: 10000 });
+    const rideRows = await rowsLocator.count();
+    expect(rideRows).toBeGreaterThanOrEqual(5);
+
+    // Spot-check that rides have enriched data (temperature should be populated from CSV)
+    await expect(page.getByRole("cell", { name: "72°F" })).toBeVisible();
+    await expect(page.getByRole("cell", { name: "65°F" })).toBeVisible();
+  });
+
+  test("navigates from settings to import rides", async ({ page }) => {
+    const userName = uniqueUser("e2e-import-settings-nav");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+
+    await expect(page).toHaveURL("/rides/import");
+    await expect(
+      page.getByRole("heading", { name: /import rides/i }),
+    ).toBeVisible();
+  });
+
+  test("redirects unauthenticated direct navigation to login", async ({
+    page,
+  }) => {
+    await page.goto("/rides/import");
+
+    await expect(page).toHaveURL(/\/login$/);
+  });
 });

From baee06ba341a55b563f96a4a478c3bfd7d5f74f1 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Fri, 10 Apr 2026 15:41:01 +0000
Subject: [PATCH 5/9] show import ride link

---
 .../src/pages/HistoryPage.css                 | 10 +++++++
 .../src/pages/HistoryPage.test.tsx            | 27 +++++++++++++++++++
 .../src/pages/HistoryPage.tsx                 |  3 +++
 .../src/pages/RecordRidePage.test.tsx         | 18 +++++++++++++
 .../src/pages/RecordRidePage.tsx              |  3 +++
 5 files changed, 61 insertions(+)

diff --git a/src/BikeTracking.Frontend/src/pages/HistoryPage.css b/src/BikeTracking.Frontend/src/pages/HistoryPage.css
index f49b5ed..6718b4c 100644
--- a/src/BikeTracking.Frontend/src/pages/HistoryPage.css
+++ b/src/BikeTracking.Frontend/src/pages/HistoryPage.css
@@ -12,6 +12,16 @@
   color: #0f172a;
 }
 
+.history-page-import-link {
+  margin: 0.35rem 0 0;
+  color: #475569;
+}
+
+.history-page-import-link a {
+  color: #0f766e;
+  font-weight: 600;
+}
+
 .history-page-summaries {
   display: grid;
   gap: 0.75rem;
diff --git a/src/BikeTracking.Frontend/src/pages/HistoryPage.test.tsx b/src/BikeTracking.Frontend/src/pages/HistoryPage.test.tsx
index 5ef1246..61bb2b0 100644
--- a/src/BikeTracking.Frontend/src/pages/HistoryPage.test.tsx
+++ b/src/BikeTracking.Frontend/src/pages/HistoryPage.test.tsx
@@ -1,5 +1,6 @@
 import { describe, it, expect, beforeEach, vi } from 'vitest'
 import { fireEvent, render, screen, waitFor, within } from '@testing-library/react'
+import { BrowserRouter } from 'react-router-dom'
 import { HistoryPage } from './HistoryPage'
 import * as ridesService from '../services/ridesService'
 
@@ -78,6 +79,32 @@ describe('HistoryPage', () => {
     })
   })
 
+  it('should render an import rides link', async () => {
+    mockGetRideHistory.mockResolvedValue({
+      summaries: {
+        thisMonth: { miles: 0, rideCount: 0, period: 'thisMonth' },
+        thisYear: { miles: 0, rideCount: 0, period: 'thisYear' },
+        allTime: { miles: 0, rideCount: 0, period: 'allTime' },
+      },
+      filteredTotal: { miles: 0, rideCount: 0, period: 'filtered' },
+      rides: [],
+      page: 1,
+      pageSize: 25,
+      totalRows: 0,
+    })
+
+    render(
+      <BrowserRouter>
+        <HistoryPage />
+      </BrowserRouter>
+    )
+
+    await waitFor(() => {
+      const importLink = screen.getByRole('link', { name: /import rides from csv/i })
+      expect(importLink).toHaveAttribute('href', '/rides/import')
+    })
+  })
+
   it('should render ride grid with ride data', async () => {
     mockGetRideHistory.mockResolvedValue({
       summaries: {
diff --git a/src/BikeTracking.Frontend/src/pages/HistoryPage.tsx b/src/BikeTracking.Frontend/src/pages/HistoryPage.tsx
index 7ac09d4..ac7381f 100644
--- a/src/BikeTracking.Frontend/src/pages/HistoryPage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/HistoryPage.tsx
@@ -560,6 +560,9 @@ export function HistoryPage() {
     <main className="history-page">
       <header className="history-page-header">
         <h1>Ride History</h1>
+        <p className="history-page-import-link">
+          Need to add older rides? <a href="/rides/import">Import rides from CSV</a>.
+        </p>
       </header>
 
       <section className="history-page-filters" aria-label="Date range filters">
diff --git a/src/BikeTracking.Frontend/src/pages/RecordRidePage.test.tsx b/src/BikeTracking.Frontend/src/pages/RecordRidePage.test.tsx
index b8d727a..79400d0 100644
--- a/src/BikeTracking.Frontend/src/pages/RecordRidePage.test.tsx
+++ b/src/BikeTracking.Frontend/src/pages/RecordRidePage.test.tsx
@@ -64,6 +64,24 @@ describe('RecordRidePage', () => {
     })
   })
 
+  it('should render an import rides link', async () => {
+    mockGetRideDefaults.mockResolvedValue({
+      hasPreviousRide: false,
+      defaultRideDateTimeLocal: new Date().toISOString(),
+    })
+
+    render(
+      <BrowserRouter>
+        <RecordRidePage />
+      </BrowserRouter>
+    )
+
+    await waitFor(() => {
+      const importLink = screen.getByRole('link', { name: /import rides from csv/i })
+      expect(importLink).toHaveAttribute('href', '/rides/import')
+    })
+  })
+
   it('should default date/time to now', async () => {
     const now = new Date()
     mockGetRideDefaults.mockResolvedValue({
diff --git a/src/BikeTracking.Frontend/src/pages/RecordRidePage.tsx b/src/BikeTracking.Frontend/src/pages/RecordRidePage.tsx
index 3cb0b9c..9c405e7 100644
--- a/src/BikeTracking.Frontend/src/pages/RecordRidePage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/RecordRidePage.tsx
@@ -260,6 +260,9 @@ export function RecordRidePage() {
   return (
     <div className="record-ride-page">
       <h1>Record a Ride</h1>
+      <p>
+        Need to add past rides in bulk? <a href="/rides/import">Import rides from CSV</a>.
+      </p>
 
       {successMessage && <div className="success-message">{successMessage}</div>}
       {errorMessage && <div className="error-message">{errorMessage}</div>}

From 3a29dd0fbc5abaab1e026d77a55c315ba7525c4d Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Fri, 10 Apr 2026 16:03:30 +0000
Subject: [PATCH 6/9] harden CSV import

---
 .../Application/Imports/CsvParserTests.cs     |  38 +++++
 .../CsvRideImportServicePreviewTests.cs       | 148 ++++++++++++++++++
 .../Application/Imports/CsvParser.cs          |   3 +-
 .../Imports/CsvRideImportService.cs           |  14 +-
 src/BikeTracking.AppHost/AppHost.cs           |   5 +-
 .../pages/import-rides/ImportRidesPage.tsx    |   2 +-
 6 files changed, 206 insertions(+), 4 deletions(-)
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs

diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
index 21a7916..938f869 100644
--- a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
@@ -4,6 +4,44 @@ namespace BikeTracking.Api.Tests.Application.Imports;
 
 public sealed class CsvParserTests
 {
+    [Fact]
+    public void Parse_WithUtf8BomHeader_ParsesRows()
+    {
+        // common from spreadsheet exports, the BOM should be ignored and not cause an extra header row to be added with the BOM as part of the first column name
+        var csv =
+            "\uFEFFDate,Miles,Time,Temp,Tags,Notes\r\n1/6/2026,4.35,,21,,\r\n1/6/2026,4.35,,44,,\r\n1/7/2026,4.35,,29,,\r\n";
+
+        var result = CsvParser.Parse(csv);
+
+        Assert.Equal(3, result.Rows.Count);
+        Assert.Equal("1/6/2026", result.Rows[0].Date);
+        Assert.Equal("4.35", result.Rows[0].Miles);
+        Assert.Equal("21", result.Rows[0].Temp);
+    }
+
+    [Fact]
+    public void Parse_ExampleCsv_ParsesRows()
+    {
+        var csv =
+            "Date,Miles,Time,Temp,Tags,Notes\r\n1/6/2026,4.35,,21,,\r\n1/6/2026,4.35,,44,,\r\n1/7/2026,4.35,,29,,\r\n";
+
+        var result = CsvParser.Parse(csv);
+
+        Assert.Equal(3, result.Rows.Count);
+        Assert.Equal(1, result.Rows[0].RowNumber);
+        Assert.Equal("1/6/2026", result.Rows[0].Date);
+        Assert.Equal("4.35", result.Rows[0].Miles);
+        Assert.Null(result.Rows[0].Time);
+        Assert.Equal("21", result.Rows[0].Temp);
+
+        Assert.Equal(2, result.Rows[1].RowNumber);
+        Assert.Equal("44", result.Rows[1].Temp);
+
+        Assert.Equal(3, result.Rows[2].RowNumber);
+        Assert.Equal("1/7/2026", result.Rows[2].Date);
+        Assert.Equal("29", result.Rows[2].Temp);
+    }
+
     [Fact]
     public void Parse_WithCaseInsensitiveHeaders_ParsesRows()
     {
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs
new file mode 100644
index 0000000..e5b698a
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs
@@ -0,0 +1,148 @@
+using System.Text;
+using BikeTracking.Api.Application.Imports;
+using BikeTracking.Api.Contracts;
+using BikeTracking.Api.Infrastructure.Persistence.Entities;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class CsvRideImportServicePreviewTests
+{
+    [Fact]
+    public async Task PreviewAsync_WithUtf8BomCsvContent_ParsesRows()
+    {
+        var service = CreateService();
+        var csv = "Date,Miles,Time,Temp,Tags,Notes\r\n1/6/2026,4.35,,21,,\r\n";
+        var bytes = Encoding.UTF8.GetPreamble().Concat(Encoding.UTF8.GetBytes(csv)).ToArray();
+
+        var result = await service.PreviewAsync(
+            riderId: 42,
+            new ImportPreviewRequest("rides.csv", Convert.ToBase64String(bytes)),
+            CancellationToken.None
+        );
+
+        Assert.Equal(1, result.TotalRows);
+        Assert.Equal(1, result.ValidRows);
+        Assert.Equal("1/6/2026", result.Rows[0].Date);
+        Assert.Equal(4.35m, result.Rows[0].Miles);
+        Assert.Equal(21m, result.Rows[0].Temperature);
+    }
+
+    [Fact]
+    public async Task PreviewAsync_WithUtf16LeBomCsvContent_ParsesRows()
+    {
+        var service = CreateService();
+        var csv = "Date,Miles,Time,Temp,Tags,Notes\r\n1/7/2026,4.35,,29,,\r\n";
+        var bytes = Encoding.Unicode.GetPreamble().Concat(Encoding.Unicode.GetBytes(csv)).ToArray();
+
+        var result = await service.PreviewAsync(
+            riderId: 42,
+            new ImportPreviewRequest("rides.csv", Convert.ToBase64String(bytes)),
+            CancellationToken.None
+        );
+
+        Assert.Equal(1, result.TotalRows);
+        Assert.Equal(1, result.ValidRows);
+        Assert.Equal("1/7/2026", result.Rows[0].Date);
+        Assert.Equal(4.35m, result.Rows[0].Miles);
+        Assert.Equal(29m, result.Rows[0].Temperature);
+    }
+
+    private static CsvRideImportService CreateService()
+    {
+        return new CsvRideImportService(
+            new TestImportJobRepository(),
+            new EmptyDuplicateResolutionService(),
+            new NoOpImportJobProcessor()
+        );
+    }
+
+    private sealed class TestImportJobRepository : IImportJobRepository
+    {
+        private long _nextJobId = 1;
+
+        public Task<ImportJobEntity> CreateJobAsync(
+            long riderId,
+            string fileName,
+            int totalRows,
+            int invalidRows,
+            CancellationToken cancellationToken
+        )
+        {
+            var entity = new ImportJobEntity
+            {
+                Id = _nextJobId++,
+                RiderId = riderId,
+                FileName = fileName,
+                TotalRows = totalRows,
+                ProcessedRows = 0,
+                ImportedRows = 0,
+                SkippedRows = 0,
+                FailedRows = invalidRows,
+                Status = "awaiting-confirmation",
+                CreatedAtUtc = DateTime.UtcNow,
+            };
+
+            return Task.FromResult(entity);
+        }
+
+        public Task AddRowsAsync(
+            long importJobId,
+            IReadOnlyList<ImportRowEntity> rows,
+            CancellationToken cancellationToken
+        ) => Task.CompletedTask;
+
+        public Task<ImportJobEntity?> GetJobAsync(
+            long riderId,
+            long importJobId,
+            CancellationToken cancellationToken
+        ) => Task.FromResult<ImportJobEntity?>(null);
+
+        public Task<ImportJobEntity?> GetJobReadOnlyAsync(
+            long riderId,
+            long importJobId,
+            CancellationToken cancellationToken
+        ) => Task.FromResult<ImportJobEntity?>(null);
+
+        public Task<bool> HasActiveImportAsync(
+            long riderId,
+            long excludeJobId,
+            CancellationToken cancellationToken
+        ) => Task.FromResult(false);
+
+        public Task<IReadOnlyList<ImportRowEntity>> GetJobRowsAsync(
+            long importJobId,
+            CancellationToken cancellationToken
+        ) => Task.FromResult<IReadOnlyList<ImportRowEntity>>([]);
+
+        public Task<IReadOnlyList<ImportRowEntity>> GetPendingRowsAsync(
+            long importJobId,
+            CancellationToken cancellationToken
+        ) => Task.FromResult<IReadOnlyList<ImportRowEntity>>([]);
+
+        public Task ReloadJobAsync(ImportJobEntity job, CancellationToken cancellationToken) =>
+            Task.CompletedTask;
+
+        public Task SaveChangesAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+    }
+
+    private sealed class EmptyDuplicateResolutionService : IDuplicateResolutionService
+    {
+        public Task<
+            IReadOnlyDictionary<int, IReadOnlyList<ImportDuplicateMatch>>
+        > GetDuplicateMatchesAsync(
+            long riderId,
+            IReadOnlyList<ImportDuplicateCandidate> candidates,
+            CancellationToken cancellationToken
+        )
+        {
+            IReadOnlyDictionary<int, IReadOnlyList<ImportDuplicateMatch>> lookup =
+                new Dictionary<int, IReadOnlyList<ImportDuplicateMatch>>();
+            return Task.FromResult(lookup);
+        }
+    }
+
+    private sealed class NoOpImportJobProcessor : IImportJobProcessor
+    {
+        public void Enqueue(long riderId, long importJobId) { }
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Imports/CsvParser.cs b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
index c3bc57b..6fd1305 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvParser.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
@@ -84,5 +84,6 @@ public static ParsedCsvDocument Parse(string csvText)
         return new ParsedCsvDocument(rows);
     }
 
-    private static string NormalizeHeader(string value) => value.Trim().ToUpperInvariant();
+    private static string NormalizeHeader(string value) =>
+        value.Trim().Trim('\uFEFF').ToUpperInvariant();
 }
diff --git a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
index 9af0454..dc5af1c 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
@@ -21,7 +21,7 @@ CancellationToken cancellationToken
         ArgumentException.ThrowIfNullOrWhiteSpace(request.ContentBase64);
 
         var csvBytes = Convert.FromBase64String(request.ContentBase64);
-        var csvText = Encoding.UTF8.GetString(csvBytes);
+        var csvText = DecodeCsvText(csvBytes);
         var parsedDocument = CsvParser.Parse(csvText);
 
         var (previewRows, importRows, validRows) = BuildRowData(parsedDocument);
@@ -193,6 +193,18 @@ CancellationToken cancellationToken
         );
     }
 
+    private static string DecodeCsvText(byte[] csvBytes)
+    {
+        using var stream = new MemoryStream(csvBytes);
+        using var reader = new StreamReader(
+            stream,
+            encoding: Encoding.UTF8,
+            detectEncodingFromByteOrderMarks: true
+        );
+
+        return reader.ReadToEnd();
+    }
+
     private static (
         List<ImportPreviewRow> PreviewRows,
         List<ImportRowEntity> ImportRows,
diff --git a/src/BikeTracking.AppHost/AppHost.cs b/src/BikeTracking.AppHost/AppHost.cs
index ea01664..63d2954 100644
--- a/src/BikeTracking.AppHost/AppHost.cs
+++ b/src/BikeTracking.AppHost/AppHost.cs
@@ -52,6 +52,9 @@
     .WithReference(apiService)
     .WaitFor(apiService);
 
-apiService.PublishWithContainerFiles(webFrontend, "wwwroot");
+if (builder.ExecutionContext.IsPublishMode)
+{
+    apiService.PublishWithContainerFiles(webFrontend, "wwwroot");
+}
 
 builder.Build().Run();
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
index f44bc1d..b3032b9 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
@@ -368,7 +368,7 @@ export function ImportRidesPage() {
           />
         ) : (
           <p className="import-rides-placeholder">
-            Progress tracking and cancellation continue in the next implementation slice.
+            Start an import to see progress and cancellation controls.
           </p>
         )}
       </section>

From 11f247360bc9a3d801c2205798f03b951902d6e8 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Fri, 10 Apr 2026 18:53:15 +0000
Subject: [PATCH 7/9] skip empty rows

---
 specs/013-csv-ride-import/plan.md             |   2 +
 specs/013-csv-ride-import/spec.md             |   4 +-
 specs/013-csv-ride-import/tasks.md            |  27 ++
 .../Application/Imports/CsvParserTests.cs     |  13 +
 .../CsvRideImportServicePreviewTests.cs       |  20 ++
 .../Imports/ImportProgressNotifierTests.cs    | 109 ++++++++
 .../Endpoints/ImportEndpointsTests.cs         |  24 ++
 .../Application/Imports/CsvParser.cs          |  31 ++-
 .../Notifications/ImportProgressHub.cs        |  40 +++
 .../Notifications/ImportProgressHubAuth.cs    |  13 +
 .../Notifications/ImportProgressNotifier.cs   |  19 +-
 .../UserIdHeaderAuthenticationHandler.cs      |  11 +
 src/BikeTracking.Api/Program.cs               |   2 +
 src/BikeTracking.Frontend/package-lock.json   | 177 ++++++++++++-
 src/BikeTracking.Frontend/package.json        |   1 +
 .../import-rides/ImportRidesPage.test.tsx     | 244 +++++++++++++++++-
 .../pages/import-rides/ImportRidesPage.tsx    |  97 ++++++-
 .../src/services/import-progress-realtime.ts  | 122 +++++++++
 .../tests/e2e/import-rides.spec.ts            | 164 ++++++++++++
 19 files changed, 1097 insertions(+), 23 deletions(-)
 create mode 100644 src/BikeTracking.Api.Tests/Application/Imports/ImportProgressNotifierTests.cs
 create mode 100644 src/BikeTracking.Api/Application/Notifications/ImportProgressHub.cs
 create mode 100644 src/BikeTracking.Api/Application/Notifications/ImportProgressHubAuth.cs
 create mode 100644 src/BikeTracking.Frontend/src/services/import-progress-realtime.ts

diff --git a/specs/013-csv-ride-import/plan.md b/specs/013-csv-ride-import/plan.md
index 202bfd9..7dd7833 100644
--- a/specs/013-csv-ride-import/plan.md
+++ b/specs/013-csv-ride-import/plan.md
@@ -132,6 +132,8 @@ src/BikeTracking.Frontend/src/
 
 Resolved in `research.md`:
 - CSV parsing strategy and header normalization
+- CSV parser skips fully empty rows (`Date`,`Miles`,`Time`,`Temp`,`Tags`,`Notes` all blank) so blank separators do not count as invalid import rows
+- BOM-aware CSV upload decoding in preview path (UTF-8/UTF-16 BOM detection, UTF-8 fallback)
 - Duplicate key policy (date+miles) and override behavior
 - Progress signaling milestones and ETA rounding algorithm
 - Cache-first enrichment with external lookup fallback and retry/throttle rules
diff --git a/specs/013-csv-ride-import/spec.md b/specs/013-csv-ride-import/spec.md
index 0a8a332..15f9fd4 100644
--- a/specs/013-csv-ride-import/spec.md
+++ b/specs/013-csv-ride-import/spec.md
@@ -116,6 +116,7 @@ The import functionality is discoverable from the Settings page via a clearly la
 - What happens if the real-time connection is lost during import? → The import continues server-side. When the rider reconnects or refreshes, they see the current state (in-progress with latest percentage, or completed with summary).
 - What happens when a CSV row has extra columns beyond the expected six? → Extra columns are ignored silently.
 - What happens when a CSV row has fewer columns than expected? → Missing optional columns are treated as empty. Missing required columns (Date, Miles) cause that row to be flagged as invalid.
+- What happens when a CSV row is fully empty (all six columns blank, e.g., `,,,,,`)? → The row is skipped during parsing and excluded from preview/import totals.
 - What happens when the rider starts a second import while one is already in progress? → The system prevents concurrent imports for the same rider, showing a message: "An import is already in progress."
 - What happens when the rider cancels mid-import? → Processing stops after the current row finishes. All rides imported up to that point remain in the rider's history. The summary reflects the partial import (rows imported, rows remaining/cancelled).
 - What happens when multiple rides exist on the same date in the rider's history? → Duplicate detection flags a match only when both date and miles are identical. A rider with a morning 8.5-mile commute and an evening 12-mile ride would not trigger a duplicate for either if the CSV rows have different mileage. If a CSV row matches on date+miles with any existing ride, the dialog shows all matching existing rides alongside the incoming row.
@@ -150,6 +151,7 @@ The import functionality is discoverable from the Settings page via a clearly la
 - **FR-022**: System MUST restrict import page access to authenticated riders only.
 - **FR-023**: System MUST allow the rider to cancel an in-progress import. Cancellation stops processing of remaining rows; rides already imported are kept and not rolled back.
 - **FR-024**: System MUST throttle external API lookups (gas price and weather) to a maximum of 4 calls per second during import to avoid hitting external API rate limits.
+- **FR-026**: System MUST skip fully empty CSV rows (all mapped fields blank) during parsing, excluding those rows from preview/import totals and validation counts.
 
 ### Key Entities
 
@@ -161,7 +163,7 @@ The import functionality is discoverable from the Settings page via a clearly la
 
 ## Assumptions
 
-- The rider's CSV is encoded in UTF-8 (or ASCII-compatible). Other encodings may produce garbled text.
+- The rider's CSV decoding is BOM-aware. UTF-8 and UTF-16 BOM-encoded files are supported; files without BOM default to UTF-8 decoding.
 - Date formats attempted during parsing include: YYYY-MM-DD, MM/DD/YYYY, M/D/YYYY, DD-MMM-YYYY, and MMM DD YYYY. Dates that don't match any recognized format are flagged as invalid.
 - The Tags column may contain comma-separated or semicolon-separated tag values within a single cell.
 - The Notes column may contain free-text of any length (within reason given file size limits).
diff --git a/specs/013-csv-ride-import/tasks.md b/specs/013-csv-ride-import/tasks.md
index a18a5a5..1cf3353 100644
--- a/specs/013-csv-ride-import/tasks.md
+++ b/specs/013-csv-ride-import/tasks.md
@@ -129,6 +129,33 @@
 - [X] T048 [US3] Create import progress panel component in `src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx`
 - [X] T049 [US3] Integrate progress subscription, ETA, and cancel action in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
 
+### US3 Follow-up: SignalR push path completion
+
+- [X] T080 [P] [US3] Add backend hub contract tests for rider/job event isolation in `src/BikeTracking.Api.Tests/Application/Imports/ImportProgressNotifierTests.cs`
+- [X] T081 [P] [US3] Add endpoint integration test that maps import progress hub and verifies authenticated negotiation in `src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs`
+- [X] T082 [P] [US3] Add frontend unit tests for realtime event apply/reconcile logic in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+- [X] T083 [P] [US3] Add frontend unit tests for fallback polling when SignalR disconnects in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+- [X] T084 [US3] Add SignalR service registration and map import progress hub endpoint in `src/BikeTracking.Api/Program.cs`
+- [X] T085 [US3] Implement rider-scoped import progress hub and group naming helper in `src/BikeTracking.Api/Application/Notifications/ImportProgressHub.cs`
+- [X] T086 [US3] Add reusable rider claim helper for hub/endpoint auth alignment in `src/BikeTracking.Api/Application/Notifications/ImportProgressHubAuth.cs`
+- [X] T087 [US3] Update import progress notifier to publish hub events while retaining structured log output in `src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs`
+- [X] T088 [US3] Add strongly typed frontend SignalR progress payload model in `src/BikeTracking.Frontend/src/services/import-progress-realtime.ts`
+- [X] T089 [US3] Implement frontend SignalR connection/subscription wrapper with reconnect callbacks in `src/BikeTracking.Frontend/src/services/import-progress-realtime.ts`
+- [X] T090 [US3] Integrate realtime subscription into import page lifecycle with status merge logic in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T091 [US3] Implement automatic polling fallback activation/deactivation on hub state changes in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T092 [US3] Add E2E test verifying realtime progress updates without waiting for polling interval in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+- [X] T093 [US3] Add E2E test verifying fallback polling after forced hub disconnect and eventual completion in `src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts`
+
+### US1 Follow-up: CSV decoding and blank-row hardening
+
+- [X] T094 [P] [US1] Add parser regression test for UTF-8 BOM headers in `src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs`
+- [X] T095 [P] [US1] Add preview-service regression tests for BOM-aware decoding (UTF-8/UTF-16 BOM) in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs`
+- [X] T096 [P] [US1] Add parser test that fully empty rows (`,,,,,`) are skipped in `src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs`
+- [X] T097 [P] [US1] Add preview-service test that fully empty rows are excluded from import totals in `src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs`
+- [X] T098 [US1] Implement BOM-safe header normalization in `src/BikeTracking.Api/Application/Imports/CsvParser.cs`
+- [X] T099 [US1] Implement BOM-aware CSV byte decoding in preview path in `src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs`
+- [X] T100 [US1] Implement fully-empty-row skip behavior in `src/BikeTracking.Api/Application/Imports/CsvParser.cs`
+
 **Checkpoint**: User Story 3 is independently functional.
 
 ---
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
index 938f869..2fa61ab 100644
--- a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
@@ -42,6 +42,19 @@ public void Parse_ExampleCsv_ParsesRows()
         Assert.Equal("29", result.Rows[2].Temp);
     }
 
+    [Fact]
+    public void Parse_WithFullyEmptyRow_SkipsTheRow()
+    {
+        var csv =
+            "Date,Miles,Time,Temp,Tags,Notes\r\n1/6/2026,4.35,,21,,\r\n,,,,,\r\n1/7/2026,4.35,,29,,\r\n";
+
+        var result = CsvParser.Parse(csv);
+
+        Assert.Equal(2, result.Rows.Count);
+        Assert.Equal("1/6/2026", result.Rows[0].Date);
+        Assert.Equal("1/7/2026", result.Rows[1].Date);
+    }
+
     [Fact]
     public void Parse_WithCaseInsensitiveHeaders_ParsesRows()
     {
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs
index e5b698a..f51bd40 100644
--- a/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvRideImportServicePreviewTests.cs
@@ -47,6 +47,26 @@ public async Task PreviewAsync_WithUtf16LeBomCsvContent_ParsesRows()
         Assert.Equal(29m, result.Rows[0].Temperature);
     }
 
+    [Fact]
+    public async Task PreviewAsync_WithFullyEmptyCsvRow_SkipsEmptyRow()
+    {
+        var service = CreateService();
+        var csv = "Date,Miles,Time,Temp,Tags,Notes\r\n1/7/2026,4.35,,29,,\r\n,,,,,\r\n";
+        var bytes = Encoding.UTF8.GetBytes(csv);
+
+        var result = await service.PreviewAsync(
+            riderId: 42,
+            new ImportPreviewRequest("rides.csv", Convert.ToBase64String(bytes)),
+            CancellationToken.None
+        );
+
+        Assert.Equal(1, result.TotalRows);
+        Assert.Equal(1, result.ValidRows);
+        Assert.Equal(0, result.InvalidRows);
+        Assert.Single(result.Rows);
+        Assert.Equal("1/7/2026", result.Rows[0].Date);
+    }
+
     private static CsvRideImportService CreateService()
     {
         return new CsvRideImportService(
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressNotifierTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressNotifierTests.cs
new file mode 100644
index 0000000..1b8d514
--- /dev/null
+++ b/src/BikeTracking.Api.Tests/Application/Imports/ImportProgressNotifierTests.cs
@@ -0,0 +1,109 @@
+using BikeTracking.Api.Application.Notifications;
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging;
+
+namespace BikeTracking.Api.Tests.Application.Imports;
+
+public sealed class ImportProgressNotifierTests
+{
+    [Fact]
+    public async Task NotifyProgressAsync_SendsToRiderJobScopedGroup()
+    {
+        var hubContext = new FakeHubContext();
+        var logger = new LoggerFactory().CreateLogger<ImportProgressNotifier>();
+        var notifier = new ImportProgressNotifier(logger, hubContext);
+
+        var payload = new ImportProgressNotification(
+            RiderId: 11,
+            ImportJobId: 99,
+            Status: "processing",
+            PercentComplete: 50,
+            EtaMinutesRounded: 5,
+            ProcessedRows: 25,
+            TotalRows: 50,
+            ImportedRows: 24,
+            SkippedRows: 0,
+            FailedRows: 1,
+            EmittedAtUtc: DateTime.UtcNow
+        );
+
+        await notifier.NotifyProgressAsync(payload, CancellationToken.None);
+
+        Assert.Equal(ImportProgressGroups.RiderJob(11, 99), hubContext.LastGroupName);
+        Assert.Equal("import.progress", hubContext.LastMethodName);
+        Assert.NotNull(hubContext.LastNotification);
+        Assert.Equal(11, hubContext.LastNotification!.RiderId);
+        Assert.Equal(99, hubContext.LastNotification.ImportJobId);
+    }
+
+    private sealed class FakeHubContext : IHubContext<ImportProgressHub>
+    {
+        private readonly FakeHubClients _clients;
+
+        public FakeHubContext()
+        {
+            _clients = new FakeHubClients(this);
+        }
+
+        public string? LastGroupName { get; private set; }
+
+        public string? LastMethodName { get; private set; }
+
+        public ImportProgressNotification? LastNotification { get; private set; }
+
+        public IHubClients Clients => _clients;
+
+        public IGroupManager Groups => throw new NotSupportedException();
+
+        private sealed class FakeHubClients(FakeHubContext owner) : IHubClients
+        {
+            private readonly FakeHubContext _owner = owner;
+
+            public IClientProxy All => throw new NotSupportedException();
+
+            public IClientProxy AllExcept(IReadOnlyList<string> excludedConnectionIds) =>
+                throw new NotSupportedException();
+
+            public IClientProxy Client(string connectionId) => throw new NotSupportedException();
+
+            public IClientProxy Clients(IReadOnlyList<string> connectionIds) =>
+                throw new NotSupportedException();
+
+            public IClientProxy Group(string groupName)
+            {
+                _owner.LastGroupName = groupName;
+                return new FakeClientProxy(_owner);
+            }
+
+            public IClientProxy GroupExcept(
+                string groupName,
+                IReadOnlyList<string> excludedConnectionIds
+            ) => throw new NotSupportedException();
+
+            public IClientProxy Groups(IReadOnlyList<string> groupNames) =>
+                throw new NotSupportedException();
+
+            public IClientProxy User(string userId) => throw new NotSupportedException();
+
+            public IClientProxy Users(IReadOnlyList<string> userIds) =>
+                throw new NotSupportedException();
+        }
+
+        private sealed class FakeClientProxy(FakeHubContext owner) : IClientProxy
+        {
+            private readonly FakeHubContext _owner = owner;
+
+            public Task SendCoreAsync(
+                string method,
+                object?[] args,
+                CancellationToken cancellationToken = default
+            )
+            {
+                _owner.LastMethodName = method;
+                _owner.LastNotification = args.OfType<ImportProgressNotification>()
+                    .SingleOrDefault();
+                return Task.CompletedTask;
+            }
+        }
+    }
+}
diff --git a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
index fe6fe29..ac4a180 100644
--- a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
+++ b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
@@ -13,6 +13,28 @@ namespace BikeTracking.Api.Tests.Endpoints;
 
 public sealed class ImportEndpointsTests
 {
+    [Fact]
+    public async Task ImportProgressHub_Negotiate_RequiresAuthentication()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+
+        using var unauthorizedRequest = new HttpRequestMessage(
+            HttpMethod.Post,
+            "/hubs/import-progress/negotiate?negotiateVersion=1"
+        );
+        var unauthorizedResponse = await host.Client.SendAsync(unauthorizedRequest);
+        Assert.Equal(HttpStatusCode.Unauthorized, unauthorizedResponse.StatusCode);
+
+        using var authorizedRequest = new HttpRequestMessage(
+            HttpMethod.Post,
+            "/hubs/import-progress/negotiate?negotiateVersion=1"
+        );
+        authorizedRequest.Headers.Add("X-User-Id", userId.ToString());
+        var authorizedResponse = await host.Client.SendAsync(authorizedRequest);
+        Assert.Equal(HttpStatusCode.OK, authorizedResponse.StatusCode);
+    }
+
     [Fact]
     public async Task PostPreview_WithValidCsv_ReturnsSummaryAndRows()
     {
@@ -379,11 +401,13 @@ public static async Task<ImportApiHost> StartAsync()
             builder.Services.AddScoped<ICsvRideImportService, CsvRideImportService>();
             builder.Services.AddScoped<IImportProgressNotifier, ImportProgressNotifier>();
             builder.Services.AddSingleton<IImportJobProcessor, ImportJobProcessor>();
+            builder.Services.AddSignalR();
 
             var app = builder.Build();
             app.UseAuthentication();
             app.UseAuthorization();
             app.MapImportEndpoints();
+            app.MapHub<ImportProgressHub>("/hubs/import-progress").RequireAuthorization();
             await app.StartAsync();
 
             return new ImportApiHost(app);
diff --git a/src/BikeTracking.Api/Application/Imports/CsvParser.cs b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
index 6fd1305..d55fde8 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvParser.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvParser.cs
@@ -68,15 +68,34 @@ public static ParsedCsvDocument Parse(string csvText)
                 return string.IsNullOrWhiteSpace(value) ? null : value;
             }
 
+            var date = GetValue("DATE");
+            var miles = GetValue("MILES");
+            var time = GetValue("TIME");
+            var temp = GetValue("TEMP");
+            var tags = GetValue("TAGS");
+            var notes = GetValue("NOTES");
+
+            if (
+                date is null
+                && miles is null
+                && time is null
+                && temp is null
+                && tags is null
+                && notes is null
+            )
+            {
+                continue;
+            }
+
             rows.Add(
                 new ParsedCsvRow(
                     RowNumber: lineIndex,
-                    Date: GetValue("DATE"),
-                    Miles: GetValue("MILES"),
-                    Time: GetValue("TIME"),
-                    Temp: GetValue("TEMP"),
-                    Tags: GetValue("TAGS"),
-                    Notes: GetValue("NOTES")
+                    Date: date,
+                    Miles: miles,
+                    Time: time,
+                    Temp: temp,
+                    Tags: tags,
+                    Notes: notes
                 )
             );
         }
diff --git a/src/BikeTracking.Api/Application/Notifications/ImportProgressHub.cs b/src/BikeTracking.Api/Application/Notifications/ImportProgressHub.cs
new file mode 100644
index 0000000..5b5b0f1
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Notifications/ImportProgressHub.cs
@@ -0,0 +1,40 @@
+using Microsoft.AspNetCore.SignalR;
+
+namespace BikeTracking.Api.Application.Notifications;
+
+public static class ImportProgressGroups
+{
+    public static string RiderJob(long riderId, long importJobId) =>
+        $"import-progress:rider:{riderId}:job:{importJobId}";
+}
+
+public sealed class ImportProgressHub : Hub
+{
+    public async Task SubscribeToImportJob(long importJobId)
+    {
+        var user = Context.User;
+        if (user is null || !ImportProgressHubAuth.TryGetRiderId(user, out var riderId))
+        {
+            throw new HubException("Unauthorized rider context.");
+        }
+
+        await Groups.AddToGroupAsync(
+            Context.ConnectionId,
+            ImportProgressGroups.RiderJob(riderId, importJobId)
+        );
+    }
+
+    public async Task UnsubscribeFromImportJob(long importJobId)
+    {
+        var user = Context.User;
+        if (user is null || !ImportProgressHubAuth.TryGetRiderId(user, out var riderId))
+        {
+            throw new HubException("Unauthorized rider context.");
+        }
+
+        await Groups.RemoveFromGroupAsync(
+            Context.ConnectionId,
+            ImportProgressGroups.RiderJob(riderId, importJobId)
+        );
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Notifications/ImportProgressHubAuth.cs b/src/BikeTracking.Api/Application/Notifications/ImportProgressHubAuth.cs
new file mode 100644
index 0000000..6800805
--- /dev/null
+++ b/src/BikeTracking.Api/Application/Notifications/ImportProgressHubAuth.cs
@@ -0,0 +1,13 @@
+using System.Security.Claims;
+
+namespace BikeTracking.Api.Application.Notifications;
+
+public static class ImportProgressHubAuth
+{
+    public static bool TryGetRiderId(ClaimsPrincipal user, out long riderId)
+    {
+        riderId = default;
+        var riderClaim = user.FindFirst("sub")?.Value;
+        return long.TryParse(riderClaim, out riderId) && riderId > 0;
+    }
+}
diff --git a/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs b/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
index 34d66da..f94839d 100644
--- a/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
+++ b/src/BikeTracking.Api/Application/Notifications/ImportProgressNotifier.cs
@@ -1,5 +1,7 @@
 namespace BikeTracking.Api.Application.Notifications;
 
+using Microsoft.AspNetCore.SignalR;
+
 public sealed record ImportProgressNotification(
     long RiderId,
     long ImportJobId,
@@ -22,10 +24,13 @@ CancellationToken cancellationToken
     );
 }
 
-public sealed class ImportProgressNotifier(ILogger<ImportProgressNotifier> logger)
-    : IImportProgressNotifier
+public sealed class ImportProgressNotifier(
+    ILogger<ImportProgressNotifier> logger,
+    IHubContext<ImportProgressHub>? hubContext = null
+) : IImportProgressNotifier
 {
     private readonly ILogger<ImportProgressNotifier> _logger = logger;
+    private readonly IHubContext<ImportProgressHub>? _hubContext = hubContext;
 
     public Task NotifyProgressAsync(
         ImportProgressNotification notification,
@@ -42,6 +47,14 @@ CancellationToken cancellationToken
             notification.TotalRows
         );
 
-        return Task.CompletedTask;
+        if (_hubContext is null)
+        {
+            return Task.CompletedTask;
+        }
+
+        var group = ImportProgressGroups.RiderJob(notification.RiderId, notification.ImportJobId);
+        return _hubContext
+            .Clients.Group(group)
+            .SendAsync("import.progress", notification, cancellationToken);
     }
 }
diff --git a/src/BikeTracking.Api/Infrastructure/Security/UserIdHeaderAuthenticationHandler.cs b/src/BikeTracking.Api/Infrastructure/Security/UserIdHeaderAuthenticationHandler.cs
index f4030e3..3e07cb9 100644
--- a/src/BikeTracking.Api/Infrastructure/Security/UserIdHeaderAuthenticationHandler.cs
+++ b/src/BikeTracking.Api/Infrastructure/Security/UserIdHeaderAuthenticationHandler.cs
@@ -23,6 +23,17 @@ UrlEncoder encoder
     protected override Task<AuthenticateResult> HandleAuthenticateAsync()
     {
         var userIdString = Request.Headers[UserIdHeaderName].FirstOrDefault();
+        if (string.IsNullOrWhiteSpace(userIdString))
+        {
+            // SignalR browser websocket connections cannot send custom headers,
+            // so we allow the same user id value via access token query parameter.
+            userIdString = Request.Query["access_token"].FirstOrDefault();
+        }
+        if (string.IsNullOrWhiteSpace(userIdString))
+        {
+            userIdString = Request.Query["userId"].FirstOrDefault();
+        }
+
         if (string.IsNullOrWhiteSpace(userIdString))
         {
             return Task.FromResult(AuthenticateResult.NoResult());
diff --git a/src/BikeTracking.Api/Program.cs b/src/BikeTracking.Api/Program.cs
index 6340a65..95c2101 100644
--- a/src/BikeTracking.Api/Program.cs
+++ b/src/BikeTracking.Api/Program.cs
@@ -103,6 +103,7 @@
 });
 
 builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSignalR();
 
 // Allow any localhost origin so the Vite dev server and published frontend
 // can reach the API during local Aspire orchestration. The origin port varies
@@ -156,6 +157,7 @@
 app.MapUsersEndpoints();
 app.MapRidesEndpoints();
 app.MapImportEndpoints();
+app.MapHub<ImportProgressHub>("/hubs/import-progress").RequireAuthorization();
 app.MapDefaultEndpoints();
 
 app.Run();
diff --git a/src/BikeTracking.Frontend/package-lock.json b/src/BikeTracking.Frontend/package-lock.json
index 4cf5285..f524042 100644
--- a/src/BikeTracking.Frontend/package-lock.json
+++ b/src/BikeTracking.Frontend/package-lock.json
@@ -8,6 +8,7 @@
       "name": "biketracking-frontend",
       "version": "0.0.0",
       "dependencies": {
+        "@microsoft/signalr": "^10.0.0",
         "react": "^19.2.4",
         "react-dom": "^19.2.4",
         "react-router-dom": "^7.13.2",
@@ -853,6 +854,19 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@microsoft/signalr": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmjs.org/@microsoft/signalr/-/signalr-10.0.0.tgz",
+      "integrity": "sha512-0BRqz/uCx3JdrOqiqgFhih/+hfTERaUfCZXFB52uMaZJrKaPRzHzMuqVsJC/V3pt7NozcNXGspjKiQEK+X7P2w==",
+      "license": "MIT",
+      "dependencies": {
+        "abort-controller": "^3.0.0",
+        "eventsource": "^2.0.2",
+        "fetch-cookie": "^2.0.3",
+        "node-fetch": "^2.6.7",
+        "ws": "^7.5.10"
+      }
+    },
     "node_modules/@napi-rs/wasm-runtime": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-1.1.2.tgz",
@@ -1902,6 +1916,18 @@
         "url": "https://opencollective.com/vitest"
       }
     },
+    "node_modules/abort-controller": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/abort-controller/-/abort-controller-3.0.0.tgz",
+      "integrity": "sha512-h8lQ8tacZYnR3vNQTgibj+tODHI5/+l06Au2Pcriv/Gmet0eaj4TwWH41sO9wnHDiQsEj19q0drzdWdeAHtweg==",
+      "license": "MIT",
+      "dependencies": {
+        "event-target-shim": "^5.0.0"
+      },
+      "engines": {
+        "node": ">=6.5"
+      }
+    },
     "node_modules/acorn": {
       "version": "8.16.0",
       "dev": true,
@@ -2710,12 +2736,30 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/event-target-shim": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/event-target-shim/-/event-target-shim-5.0.1.tgz",
+      "integrity": "sha512-i/2XbnSz/uxRCU6+NdVJgKWDTM427+MqYbkQzD321DuCQJUqOuJKIA0IM2+W2xtYHdKOmZ4dR6fExsd4SXL+WQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/eventemitter3": {
       "version": "5.0.4",
       "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.4.tgz",
       "integrity": "sha512-mlsTRyGaPBjPedk6Bvw+aqbsXDtoAyAzm5MO7JgU+yVRyMQ5O8bD4Kcci7BS85f93veegeCPkL8R4GLClnjLFw==",
       "license": "MIT"
     },
+    "node_modules/eventsource": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/eventsource/-/eventsource-2.0.2.tgz",
+      "integrity": "sha512-IzUmBGPR3+oUG9dUeXynyNmf91/3zUSJg1lCktzKw47OXuhco54U3r9B7O4XX+Rb1Itm9OZ2b0RkTs10bICOxA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.0.0"
+      }
+    },
     "node_modules/expect-type": {
       "version": "1.3.0",
       "dev": true,
@@ -2796,6 +2840,31 @@
         "reusify": "^1.0.4"
       }
     },
+    "node_modules/fetch-cookie": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/fetch-cookie/-/fetch-cookie-2.2.0.tgz",
+      "integrity": "sha512-h9AgfjURuCgA2+2ISl8GbavpUdR+WGAM2McW/ovn4tVccegp8ZqCKWSBR8uRdM8dDNlx5WdKRWxBYUwteLDCNQ==",
+      "license": "Unlicense",
+      "dependencies": {
+        "set-cookie-parser": "^2.4.8",
+        "tough-cookie": "^4.0.0"
+      }
+    },
+    "node_modules/fetch-cookie/node_modules/tough-cookie": {
+      "version": "4.1.4",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.4.tgz",
+      "integrity": "sha512-Loo5UUvLD9ScZ6jh8beX1T6sO1w2/MpCRpEP7V280GKMVUQ0Jzar2U3UJPsrdbziLEMMhu3Ujnq//rhiFuIeag==",
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "psl": "^1.1.33",
+        "punycode": "^2.1.1",
+        "universalify": "^0.2.0",
+        "url-parse": "^1.5.3"
+      },
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/file-entry-cache": {
       "version": "8.0.0",
       "dev": true,
@@ -3780,6 +3849,48 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/node-fetch": {
+      "version": "2.7.0",
+      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.7.0.tgz",
+      "integrity": "sha512-c4FRfUm/dbcWZ7U+1Wq0AwCyFL+3nt2bEw05wfxSz+DWpWsitgmSgYmy2dQdWyKC1694ELPqMs/YzUSNozLt8A==",
+      "license": "MIT",
+      "dependencies": {
+        "whatwg-url": "^5.0.0"
+      },
+      "engines": {
+        "node": "4.x || >=6.0.0"
+      },
+      "peerDependencies": {
+        "encoding": "^0.1.0"
+      },
+      "peerDependenciesMeta": {
+        "encoding": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/node-fetch/node_modules/tr46": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
+      "integrity": "sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw==",
+      "license": "MIT"
+    },
+    "node_modules/node-fetch/node_modules/webidl-conversions": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
+      "integrity": "sha512-2JAn3z8AR6rjK8Sm8orRC0h/bcl/DqL7tRPdGZ4I1CjdF+EaMLmYxBHyXuKL849eucPFhvBoxMsflfOb8kxaeQ==",
+      "license": "BSD-2-Clause"
+    },
+    "node_modules/node-fetch/node_modules/whatwg-url": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-5.0.0.tgz",
+      "integrity": "sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw==",
+      "license": "MIT",
+      "dependencies": {
+        "tr46": "~0.0.3",
+        "webidl-conversions": "^3.0.0"
+      }
+    },
     "node_modules/node-releases": {
       "version": "2.0.36",
       "dev": true,
@@ -4055,9 +4166,20 @@
         "url": "https://github.com/chalk/ansi-styles?sponsor=1"
       }
     },
+    "node_modules/psl": {
+      "version": "1.15.0",
+      "resolved": "https://registry.npmjs.org/psl/-/psl-1.15.0.tgz",
+      "integrity": "sha512-JZd3gMVBAVQkSs6HdNZo9Sdo0LNcQeMNP3CozBJb3JYC/QUYZTnKxP+f8oWRX4rHP5EurWxqAHTSwUCjlNKa1w==",
+      "license": "MIT",
+      "dependencies": {
+        "punycode": "^2.3.1"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/lupomontero"
+      }
+    },
     "node_modules/punycode": {
       "version": "2.3.1",
-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=6"
@@ -4079,6 +4201,12 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/querystringify": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/querystringify/-/querystringify-2.2.0.tgz",
+      "integrity": "sha512-FIqgj2EUvTa7R50u0rGsyTftzjYmv/a3hO345bZNrqabNqjtgiDMgmo4mkUjd+nzU5oF3dClKqFIPUKybUyqoQ==",
+      "license": "MIT"
+    },
     "node_modules/queue-microtask": {
       "version": "1.2.3",
       "dev": true,
@@ -4245,6 +4373,12 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/requires-port": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/requires-port/-/requires-port-1.0.0.tgz",
+      "integrity": "sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==",
+      "license": "MIT"
+    },
     "node_modules/reselect": {
       "version": "5.1.1",
       "resolved": "https://registry.npmjs.org/reselect/-/reselect-5.1.1.tgz",
@@ -4352,7 +4486,6 @@
     },
     "node_modules/set-cookie-parser": {
       "version": "2.7.2",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/shebang-command": {
@@ -4950,6 +5083,15 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/universalify": {
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.2.0.tgz",
+      "integrity": "sha512-CJ1QgKmNg3CwvAv/kOFmtnEN05f0D/cn9QntgNOQlQF9dgvVTHj3t+8JPdjqawCHk7V/KA+fbUqzZ9XWhcqPUg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 4.0.0"
+      }
+    },
     "node_modules/update-browserslist-db": {
       "version": "1.2.3",
       "dev": true,
@@ -4987,6 +5129,16 @@
         "punycode": "^2.1.0"
       }
     },
+    "node_modules/url-parse": {
+      "version": "1.5.10",
+      "resolved": "https://registry.npmjs.org/url-parse/-/url-parse-1.5.10.tgz",
+      "integrity": "sha512-WypcfiRhfeUP9vvF0j6rw0J3hrWrw6iZv3+22h6iRMJ/8z1Tj6XfLP4DsUix5MhMPnXpiHDoKyoZ/bdCkwBCiQ==",
+      "license": "MIT",
+      "dependencies": {
+        "querystringify": "^2.1.1",
+        "requires-port": "^1.0.0"
+      }
+    },
     "node_modules/use-sync-external-store": {
       "version": "1.6.0",
       "resolved": "https://registry.npmjs.org/use-sync-external-store/-/use-sync-external-store-1.6.0.tgz",
@@ -5306,6 +5458,27 @@
         "node": "^20.17.0 || >=22.9.0"
       }
     },
+    "node_modules/ws": {
+      "version": "7.5.10",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-7.5.10.tgz",
+      "integrity": "sha512-+dbF1tHwZpXcbOJdVOkzLDxZP1ailvSxM6ZweXTegylPny803bFhA+vqBYw4s31NSAk4S2Qz+AKXK9a4wkdjcQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=8.3.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": "^5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/xml-name-validator": {
       "version": "5.0.0",
       "dev": true,
diff --git a/src/BikeTracking.Frontend/package.json b/src/BikeTracking.Frontend/package.json
index 7ca3785..b63c6c4 100644
--- a/src/BikeTracking.Frontend/package.json
+++ b/src/BikeTracking.Frontend/package.json
@@ -4,6 +4,7 @@
   "version": "0.0.0",
   "type": "module",
   "dependencies": {
+    "@microsoft/signalr": "^10.0.0",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
     "react-router-dom": "^7.13.2",
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
index 05315f5..062219c 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
@@ -1,9 +1,21 @@
-import { beforeEach, describe, expect, it, vi } from 'vitest'
-import { fireEvent, render, screen, waitFor, within } from '@testing-library/react'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { act, fireEvent, render, screen, waitFor, within } from '@testing-library/react'
 import userEvent from '@testing-library/user-event'
 import { BrowserRouter } from 'react-router-dom'
 import { ImportRidesPage } from './ImportRidesPage'
 import * as importApi from '../../services/import-api'
+import type {
+  ImportProgressRealtimeHandlers,
+  ImportProgressRealtimeSubscription,
+} from '../../services/import-progress-realtime'
+import * as realtimeApi from '../../services/import-progress-realtime'
+
+const realtimeState = vi.hoisted(() => ({
+  handlers: null as ImportProgressRealtimeHandlers | null,
+  subscription: {
+    stop: vi.fn(async () => {}),
+  } as ImportProgressRealtimeSubscription,
+}))
 
 vi.mock('../../services/import-api', () => ({
   previewImportCsv: vi.fn(),
@@ -12,15 +24,243 @@ vi.mock('../../services/import-api', () => ({
   cancelImport: vi.fn(),
 }))
 
+vi.mock('../../services/import-progress-realtime', () => ({
+  subscribeToImportProgress: vi.fn(
+    async (_importJobId: number, handlers: ImportProgressRealtimeHandlers) => {
+      realtimeState.handlers = handlers
+      return realtimeState.subscription
+    },
+  ),
+}))
+
 const mockPreviewImportCsv = vi.mocked(importApi.previewImportCsv)
 const mockStartImportCsv = vi.mocked(importApi.startImportCsv)
 const mockGetImportStatus = vi.mocked(importApi.getImportStatus)
 const mockCancelImport = vi.mocked(importApi.cancelImport)
+const mockSubscribeToImportProgress = vi.mocked(realtimeApi.subscribeToImportProgress)
 
 describe('ImportRidesPage', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     sessionStorage.clear()
+    realtimeState.handlers = null
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('applies realtime progress updates to the progress panel', async () => {
+    const user = userEvent.setup()
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 201,
+        totalRows: 2,
+        validRows: 2,
+        invalidRows: 0,
+        duplicateRows: 0,
+        requiresDuplicateResolution: false,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+          {
+            rowNumber: 2,
+            date: '2026-04-02',
+            miles: 9.5,
+            rideMinutes: 38,
+            temperature: 55,
+            tags: 'errand',
+            notes: 'afternoon',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+        ],
+      },
+    })
+    mockStartImportCsv.mockResolvedValue({
+      ok: true,
+      status: 202,
+      data: {
+        importJobId: 201,
+        status: 'processing',
+        startedAtUtc: '2026-04-10T10:10:00Z',
+      },
+    })
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 201,
+        status: 'processing',
+        totalRows: 2,
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        percentComplete: 0,
+        etaMinutesRounded: null,
+        createdAtUtc: '2026-04-10T10:09:00Z',
+        startedAtUtc: '2026-04-10T10:10:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>,
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+    await user.click(await screen.findByRole('button', { name: /start import/i }))
+
+    await waitFor(() => {
+      expect(mockSubscribeToImportProgress).toHaveBeenCalledWith(
+        201,
+        expect.objectContaining({
+          onProgress: expect.any(Function),
+          onConnectionStateChanged: expect.any(Function),
+        }),
+      )
+    })
+
+    await act(async () => {
+      realtimeState.handlers?.onConnectionStateChanged('connected')
+      realtimeState.handlers?.onProgress({
+        riderId: 42,
+        importJobId: 201,
+        status: 'processing',
+        percentComplete: 50,
+        etaMinutesRounded: 5,
+        processedRows: 1,
+        totalRows: 2,
+        importedRows: 1,
+        skippedRows: 0,
+        failedRows: 0,
+        emittedAtUtc: '2026-04-10T10:12:00Z',
+      })
+    })
+
+    await waitFor(() => {
+      expect(screen.getByText(/complete: 50%/i)).toBeInTheDocument()
+      expect(screen.getByText(/eta: ~5 minutes remaining/i)).toBeInTheDocument()
+      expect(screen.getByText(/imported: 1/i)).toBeInTheDocument()
+    })
+  })
+
+  it('falls back to polling when SignalR disconnects', async () => {
+
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 202,
+        totalRows: 1,
+        validRows: 1,
+        invalidRows: 0,
+        duplicateRows: 0,
+        requiresDuplicateResolution: false,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [],
+          },
+        ],
+      },
+    })
+    mockStartImportCsv.mockResolvedValue({
+      ok: true,
+      status: 202,
+      data: {
+        importJobId: 202,
+        status: 'processing',
+        startedAtUtc: '2026-04-10T10:20:00Z',
+      },
+    })
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 202,
+        status: 'processing',
+        totalRows: 1,
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        percentComplete: 0,
+        etaMinutesRounded: null,
+        createdAtUtc: '2026-04-10T10:19:00Z',
+        startedAtUtc: '2026-04-10T10:20:00Z',
+        completedAtUtc: null,
+        lastError: null,
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>,
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+    fireEvent.click(await screen.findByRole('button', { name: /start import/i }))
+
+    await waitFor(() => {
+      expect(mockSubscribeToImportProgress).toHaveBeenCalledWith(
+        202,
+        expect.objectContaining({
+          onProgress: expect.any(Function),
+          onConnectionStateChanged: expect.any(Function),
+        }),
+      )
+    })
+
+    await act(async () => {
+      realtimeState.handlers?.onConnectionStateChanged('disconnected')
+    })
+
+    const baselineCalls = mockGetImportStatus.mock.calls.length
+    await waitFor(
+      () => {
+        expect(mockGetImportStatus.mock.calls.length).toBeGreaterThan(baselineCalls)
+      },
+      { timeout: 3000 },
+    )
   })
 
   it('renders preview summary after successful upload preview', async () => {
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
index b3032b9..5a9a28e 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
@@ -9,6 +9,11 @@ import {
   type ImportPreviewRow,
   type ImportStatusResponse,
 } from '../../services/import-api'
+import {
+  subscribeToImportProgress,
+  type ImportProgressRealtimeNotification,
+  type ImportProgressRealtimeSubscription,
+} from '../../services/import-progress-realtime'
 import { DuplicateResolutionDialog } from '../../components/import-rides/DuplicateResolutionDialog'
 import { ImportProgressPanel } from '../../components/import-rides/ImportProgressPanel'
 import './ImportRidesPage.css'
@@ -50,6 +55,7 @@ export function ImportRidesPage() {
   const [isDuplicateDialogOpen, setIsDuplicateDialogOpen] = useState<boolean>(false)
   const [overrideAllDuplicates, setOverrideAllDuplicates] = useState<boolean>(false)
   const [duplicateResolutions, setDuplicateResolutions] = useState<ImportDuplicateResolution[]>([])
+  const [isRealtimeConnected, setIsRealtimeConnected] = useState<boolean>(false)
 
   const duplicateRows: ImportPreviewRow[] =
     preview?.rows.filter((row) => row.duplicateMatches.length > 0) ?? []
@@ -64,7 +70,7 @@ export function ImportRidesPage() {
   }, [])
 
   useEffect(() => {
-    if (status?.status !== 'processing') {
+    if (status?.status !== 'processing' || isRealtimeConnected) {
       return
     }
 
@@ -75,6 +81,77 @@ export function ImportRidesPage() {
     return () => {
       window.clearInterval(intervalId)
     }
+  }, [isRealtimeConnected, status?.importJobId, status?.status])
+
+  useEffect(() => {
+    if (status?.status !== 'processing') {
+      setIsRealtimeConnected(false)
+      return
+    }
+
+    let subscription: ImportProgressRealtimeSubscription | null = null
+    let isMounted = true
+
+    const connect = async (): Promise<void> => {
+      try {
+        subscription = await subscribeToImportProgress(status.importJobId, {
+          onProgress: (notification: ImportProgressRealtimeNotification): void => {
+            if (!isMounted || notification.importJobId !== status.importJobId) {
+              return
+            }
+
+            setStatus((current) => {
+              if (current === null || current.importJobId !== notification.importJobId) {
+                return current
+              }
+
+              return {
+                ...current,
+                status: notification.status,
+                totalRows: notification.totalRows,
+                processedRows: notification.processedRows,
+                importedRows: notification.importedRows,
+                skippedRows: notification.skippedRows,
+                failedRows: notification.failedRows,
+                percentComplete: notification.percentComplete,
+                etaMinutesRounded: notification.etaMinutesRounded ?? null,
+                completedAtUtc: isTerminalStatus(notification.status)
+                  ? notification.emittedAtUtc
+                  : current.completedAtUtc,
+              }
+            })
+
+            if (isTerminalStatus(notification.status)) {
+              clearActiveImportJobId()
+              setIsRealtimeConnected(false)
+            }
+          },
+          onConnectionStateChanged: (state): void => {
+            if (!isMounted) {
+              return
+            }
+
+            setIsRealtimeConnected(state === 'connected')
+          },
+        })
+      } catch {
+        if (!isMounted) {
+          return
+        }
+
+        setIsRealtimeConnected(false)
+      }
+    }
+
+    void connect()
+
+    return () => {
+      isMounted = false
+      setIsRealtimeConnected(false)
+      if (subscription !== null) {
+        void subscription.stop()
+      }
+    }
   }, [status?.importJobId, status?.status])
 
   function onSelectFile(event: React.ChangeEvent<HTMLInputElement>): void {
@@ -250,20 +327,22 @@ export function ImportRidesPage() {
         return
       }
 
+      const cancelled = cancelResponse.data
+
       clearActiveImportJobId()
       setStatus((current) => ({
-        importJobId: cancelResponse.data.importJobId,
-        status: cancelResponse.data.status,
+        importJobId: cancelled.importJobId,
+        status: cancelled.status,
         totalRows: current?.totalRows ?? 0,
-        processedRows: cancelResponse.data.processedRows,
-        importedRows: cancelResponse.data.importedRows,
-        skippedRows: cancelResponse.data.skippedRows,
-        failedRows: cancelResponse.data.failedRows,
+        processedRows: cancelled.processedRows,
+        importedRows: cancelled.importedRows,
+        skippedRows: cancelled.skippedRows,
+        failedRows: cancelled.failedRows,
         percentComplete: current?.percentComplete ?? null,
         etaMinutesRounded: null,
-        createdAtUtc: current?.createdAtUtc ?? cancelResponse.data.cancelledAtUtc,
+        createdAtUtc: current?.createdAtUtc ?? cancelled.cancelledAtUtc,
         startedAtUtc: current?.startedAtUtc ?? null,
-        completedAtUtc: cancelResponse.data.cancelledAtUtc,
+        completedAtUtc: cancelled.cancelledAtUtc,
         lastError: null,
       }))
     } catch {
diff --git a/src/BikeTracking.Frontend/src/services/import-progress-realtime.ts b/src/BikeTracking.Frontend/src/services/import-progress-realtime.ts
new file mode 100644
index 0000000..46a5339
--- /dev/null
+++ b/src/BikeTracking.Frontend/src/services/import-progress-realtime.ts
@@ -0,0 +1,122 @@
+import {
+  HubConnectionBuilder,
+  HubConnectionState,
+  LogLevel,
+} from "@microsoft/signalr";
+
+const API_BASE_URL =
+  (import.meta.env.VITE_API_BASE_URL as string | undefined)?.replace(
+    /\/$/,
+    "",
+  ) ?? "http://localhost:5436";
+
+const SESSION_KEY = "bike_tracking_auth_session";
+
+export type RealtimeConnectionState =
+  | "connected"
+  | "reconnecting"
+  | "disconnected";
+
+export interface ImportProgressRealtimeNotification {
+  riderId: number;
+  importJobId: number;
+  status: string;
+  percentComplete: number;
+  etaMinutesRounded?: number | null;
+  processedRows: number;
+  totalRows: number;
+  importedRows: number;
+  skippedRows: number;
+  failedRows: number;
+  emittedAtUtc: string;
+}
+
+export interface ImportProgressRealtimeHandlers {
+  onProgress: (notification: ImportProgressRealtimeNotification) => void;
+  onConnectionStateChanged: (state: RealtimeConnectionState) => void;
+}
+
+export interface ImportProgressRealtimeSubscription {
+  stop: () => Promise<void>;
+}
+
+function getUserIdHeader(): string | null {
+  try {
+    const raw = sessionStorage.getItem(SESSION_KEY);
+    if (!raw) {
+      return null;
+    }
+
+    const parsed = JSON.parse(raw) as { userId?: number };
+    if (typeof parsed.userId === "number" && parsed.userId > 0) {
+      return parsed.userId.toString();
+    }
+  } catch {
+    // Ignore malformed auth session values.
+  }
+
+  return null;
+}
+
+export async function subscribeToImportProgress(
+  importJobId: number,
+  handlers: ImportProgressRealtimeHandlers,
+): Promise<ImportProgressRealtimeSubscription> {
+  const userId = getUserIdHeader();
+  const tokenQuery = encodeURIComponent(userId ?? "");
+
+  const connection = new HubConnectionBuilder()
+    .withUrl(
+      `${API_BASE_URL}/hubs/import-progress?access_token=${tokenQuery}`,
+      {
+        headers: userId ? { "X-User-Id": userId } : {},
+        accessTokenFactory: () => userId ?? "",
+      },
+    )
+    .withAutomaticReconnect()
+    .configureLogging(LogLevel.Warning)
+    .build();
+
+  connection.on(
+    "import.progress",
+    (payload: ImportProgressRealtimeNotification) => {
+      handlers.onProgress(payload);
+    },
+  );
+
+  connection.onreconnecting(() => {
+    handlers.onConnectionStateChanged("reconnecting");
+  });
+
+  connection.onreconnected(async () => {
+    handlers.onConnectionStateChanged("connected");
+    await connection.invoke("SubscribeToImportJob", importJobId);
+  });
+
+  connection.onclose(() => {
+    handlers.onConnectionStateChanged("disconnected");
+  });
+
+  await connection.start();
+  handlers.onConnectionStateChanged("connected");
+  await connection.invoke("SubscribeToImportJob", importJobId);
+
+  return {
+    stop: async () => {
+      if (
+        connection.state === HubConnectionState.Connected ||
+        connection.state === HubConnectionState.Reconnecting
+      ) {
+        try {
+          await connection.invoke("UnsubscribeFromImportJob", importJobId);
+        } catch {
+          // Unsubscribe can fail during shutdown/reconnect races.
+        }
+      }
+
+      if (connection.state !== HubConnectionState.Disconnected) {
+        await connection.stop();
+      }
+    },
+  };
+}
diff --git a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
index 06f891c..69a7798 100644
--- a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
+++ b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
@@ -22,6 +22,80 @@ function buildCsvRows(startDateIso: string, count: number): string {
   return rows.join("\n");
 }
 
+async function installSignalRDisconnectHarness(page: {
+  addInitScript: (script: () => void) => Promise<void>;
+}): Promise<void> {
+  await page.addInitScript(() => {
+    const originalWebSocket = window.WebSocket;
+    const trackedSockets: WebSocket[] = [];
+    let blockImportSignalR = false;
+
+    const TrackedWebSocket = function (
+      this: unknown,
+      url: string | URL,
+      protocols?: string | string[],
+    ): WebSocket {
+      const socket =
+        protocols === undefined
+          ? new originalWebSocket(url)
+          : new originalWebSocket(url, protocols);
+
+      trackedSockets.push(socket);
+
+      const socketUrl = typeof url === "string" ? url : url.toString();
+      if (blockImportSignalR && socketUrl.includes("/hubs/import-progress")) {
+        window.setTimeout(() => {
+          try {
+            socket.close();
+          } catch {
+            // Ignore close race conditions.
+          }
+        }, 0);
+      }
+
+      return socket;
+    } as unknown as typeof WebSocket;
+
+    TrackedWebSocket.prototype = originalWebSocket.prototype;
+    window.WebSocket = TrackedWebSocket;
+
+    const signalrHarnessWindow = window as Window & {
+      __disconnectImportSignalR?: () => void;
+    };
+
+    signalrHarnessWindow.__disconnectImportSignalR = () => {
+      blockImportSignalR = true;
+      trackedSockets.forEach((socket) => {
+        if (socket.url.includes("/hubs/import-progress")) {
+          try {
+            socket.close();
+          } catch {
+            // Ignore close race conditions.
+          }
+        }
+      });
+    };
+  });
+}
+
+async function installSlowPollingHarness(page: {
+  addInitScript: (script: () => void) => Promise<void>;
+}): Promise<void> {
+  await page.addInitScript(() => {
+    const originalSetInterval = window.setInterval.bind(window);
+    const adjustedSetInterval = (
+      handler: TimerHandler,
+      timeout?: number,
+      ...args: unknown[]
+    ): number => {
+      const effectiveTimeout = timeout === 2000 ? 10000 : timeout;
+      return originalSetInterval(handler, effectiveTimeout, ...args);
+    };
+
+    window.setInterval = adjustedSetInterval as typeof window.setInterval;
+  });
+}
+
 test.describe("013-csv-import e2e", () => {
   test("upload preview and start import happy path", async ({ page }) => {
     const userName = uniqueUser("e2e-import-rides");
@@ -193,6 +267,96 @@ test.describe("013-csv-import e2e", () => {
     });
   });
 
+  test("shows progress updates through completion", async ({ page }) => {
+    await installSlowPollingHarness(page);
+
+    const userName = uniqueUser("e2e-import-realtime-first-update");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    const rows = buildCsvRows("2026-04-01", 60);
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(rows, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+    await expect(page.getByText(/valid rows:\s*60/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    const startedAt = Date.now();
+    await page.getByRole("button", { name: /^start import$/i }).click();
+
+    await expect(
+      page.getByText(/status:\s*(processing|completed)/i),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+
+    await expect(page.getByText(/complete:\s*\d+%/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    await expect(page.getByText(/status: completed/i)).toBeVisible({
+      timeout: 30000,
+    });
+
+    const elapsedMs = Date.now() - startedAt;
+    expect(elapsedMs).toBeLessThan(30000);
+  });
+
+  test("completes import through polling fallback after forced SignalR disconnect", async ({
+    page,
+  }) => {
+    await installSignalRDisconnectHarness(page);
+
+    const userName = uniqueUser("e2e-import-polling-fallback");
+    await createAndLoginUser(page, userName, TEST_PIN);
+
+    await page.goto("/settings");
+    await page.getByRole("link", { name: /import rides from csv/i }).click();
+    await expect(page).toHaveURL("/rides/import");
+
+    const rows = buildCsvRows("2026-04-01", 80);
+    await page.setInputFiles("#csv-upload-input", {
+      name: "rides.csv",
+      mimeType: "text/csv",
+      buffer: Buffer.from(rows, "utf8"),
+    });
+
+    await page.getByRole("button", { name: /preview import/i }).click();
+    await expect(page.getByText(/valid rows:\s*80/i)).toBeVisible({
+      timeout: 10000,
+    });
+
+    await page.getByRole("button", { name: /^start import$/i }).click();
+    await expect(
+      page.getByText(/status:\s*(processing|completed)/i),
+    ).toBeVisible({
+      timeout: 10000,
+    });
+
+    await page.evaluate(() => {
+      const signalrHarnessWindow = window as Window & {
+        __disconnectImportSignalR?: () => void;
+      };
+      signalrHarnessWindow.__disconnectImportSignalR?.();
+    });
+
+    await expect(page.getByText(/complete:\s*\d+%/i)).toBeVisible({
+      timeout: 12000,
+    });
+
+    await expect(page.getByText(/status: completed/i)).toBeVisible({
+      timeout: 35000,
+    });
+  });
+
   test("cancels import mid-run and shows partial summary", async ({ page }) => {
     const userName = uniqueUser("e2e-import-cancel");
     await createAndLoginUser(page, userName, TEST_PIN);

From 995ea0b6ed041a1e310ea9f538f6aab68206d5a4 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Tue, 14 Apr 2026 15:20:34 +0000
Subject: [PATCH 8/9] fixing bugs, example import

---
 .../contracts/api-contracts.md                |   2 +-
 specs/013-csv-ride-import/spec.md             |  26 +++-
 specs/013-csv-ride-import/tasks.md            |  26 ++++
 .../Application/Imports/CsvParserTests.cs     |  47 ++++++++
 .../DuplicateResolutionServiceTests.cs        |  34 +++++-
 .../Endpoints/ImportEndpointsTests.cs         |  32 ++++-
 .../Events/OutboxPublisherService.cs          |  37 +++---
 .../Imports/CsvRideImportService.cs           |   3 +-
 .../Application/Imports/CsvValidationRules.cs |  71 +++++++++--
 .../Imports/DuplicateResolutionService.cs     |   1 +
 .../Imports/IDuplicateResolutionService.cs    |   7 +-
 .../import-rides/ImportProgressPanel.test.tsx |   3 +-
 .../import-rides/ImportProgressPanel.tsx      |  47 +++++++-
 .../pages/import-rides/ImportRidesPage.css    | 111 +++++++++++++++++
 .../import-rides/ImportRidesPage.test.tsx     | 113 +++++++++++++++++-
 .../pages/import-rides/ImportRidesPage.tsx    |  87 ++++++++++++--
 16 files changed, 598 insertions(+), 49 deletions(-)

diff --git a/specs/013-csv-ride-import/contracts/api-contracts.md b/specs/013-csv-ride-import/contracts/api-contracts.md
index 3475242..3be4a7f 100644
--- a/specs/013-csv-ride-import/contracts/api-contracts.md
+++ b/specs/013-csv-ride-import/contracts/api-contracts.md
@@ -146,7 +146,7 @@ public sealed record ImportProgressNotification(
 
 - Required CSV columns: `Date`, `Miles` (case-insensitive)
 - Optional CSV columns: `Time`, `Temp`, `Tags`, `Notes`
-- Duplicate key: `Date + Miles`
+- Duplicate key: `Date + Miles + Temp` (Temp must also match when provided)
 - Enrichment rules:
   - Cache-first gas/weather lookup
   - On cache miss, perform external lookup
diff --git a/specs/013-csv-ride-import/spec.md b/specs/013-csv-ride-import/spec.md
index 15f9fd4..8c32dee 100644
--- a/specs/013-csv-ride-import/spec.md
+++ b/specs/013-csv-ride-import/spec.md
@@ -28,7 +28,7 @@ A rider navigates to the Settings page and selects "Import Rides." They are pres
 
 ### User Story 2 - Duplicate Detection and Resolution (Priority: P1)
 
-During import, the system checks each row's date and miles against the rider's existing ride history. If duplicates are found (an existing ride with the same date and same miles value), the rider is prompted with a dialog showing the conflicting rows side-by-side (existing ride vs. incoming CSV row). The rider can resolve each duplicate individually, or use an "Override All Duplicates" toggle to skip duplicate checking entirely and import everything. Rides on the same date but with different mileage are treated as distinct trips and imported without prompting.
+During import, the system checks each row's date, miles, and Temp (when provided) against the rider's existing ride history. If duplicates are found (an existing ride with the same date, same miles value, and matching Temp value when present), the rider is prompted with a dialog showing the conflicting rows side-by-side (existing ride vs. incoming CSV row). The rider can resolve each duplicate individually, or use an "Override All Duplicates" toggle to skip duplicate checking entirely and import everything. Rides on the same date with different mileage or different Temp are treated as distinct trips and imported without prompting.
 
 **Why this priority**: Without duplicate handling, importing a CSV could corrupt the rider's history with repeated entries — especially likely if the rider re-imports the same file or has partial data already recorded. This is a data-integrity concern and is co-equal with the core import.
 
@@ -41,6 +41,7 @@ During import, the system checks each row's date and miles against the rider's e
 3. **Given** the duplicate dialog is displayed, **When** the rider chooses "Replace with Import," **Then** the existing ride is superseded by the imported row (via a new corrective event) and the import continues.
 4. **Given** a CSV with multiple duplicate dates, **When** the first duplicate is encountered, **Then** the dialog also offers an "Override All Duplicates" option. If selected, all remaining duplicates are imported without further prompts (creating new ride records alongside existing ones).
 5. **Given** the rider enables "Override All Duplicates" before starting the import, **When** duplicates are encountered, **Then** all rows are imported without any duplicate prompts.
+6. **Given** the duplicate dialog is displayed for a previewed import, **When** the rider clicks "Cancel," **Then** the previewed job is discarded, the page resets to a clean "new import" state, and after refresh the rider can upload and preview a different CSV without residual import state.
 
 ---
 
@@ -122,6 +123,18 @@ The import functionality is discoverable from the Settings page via a clearly la
 - What happens when multiple rides exist on the same date in the rider's history? → Duplicate detection flags a match only when both date and miles are identical. A rider with a morning 8.5-mile commute and an evening 12-mile ride would not trigger a duplicate for either if the CSV rows have different mileage. If a CSV row matches on date+miles with any existing ride, the dialog shows all matching existing rides alongside the incoming row.
 - What happens when an external gas price or weather API call fails during enrichment? → The system retries once. If the retry also fails, enrichment is skipped for that ride (the ride is still imported without that data) and the import continues with the next row.
 
+---
+
+## Known Limitations
+
+**Preview Performance**: The preview phase (CSV parsing + duplicate detection) loads all rider rides into memory and checks each CSV row against the full history. For riders with large ride histories (1000+ rides) or large CSV uploads (500+ rows), the preview operation may take 5–30 seconds with no real-time progress updates. **Mitigation**: A preview progress spinner is displayed during the preview phase with a message indicating the operation is in progress. For very large imports, consider splitting the CSV into smaller batches (100–200 rows per file) or pre-filtering to recent years to reduce matching overhead.
+
+**Duplicate Detection on Large Datasets**: Duplicate lookup is performed in-memory (LINQ-to-Objects) after loading all rider rides from the database. This is efficient for typical riders (up to ~500 rides) but will degrade for riders with 5000+ historical rides. **Mitigation**: In future phases, duplicate detection could be optimized via SQL-level batch lookup or streaming row processing if needed.
+
+**Preview Summary Display**: When a preview contains 100+ rows, the row list will render inline and may cause the browser to slow down. **Mitigation**: In future phases, the preview row list should be paginated or virtualized if needed to handle massive CSV exports.
+
+---
+
 ## Requirements *(mandatory)*
 
 ### Functional Requirements
@@ -133,7 +146,7 @@ The import functionality is discoverable from the Settings page via a clearly la
 - **FR-005**: System MUST validate each row against existing ride-entry rules: miles between 0 and 200 (exclusive of zero), parseable date, optional positive duration for Time.
 - **FR-006**: System MUST display a preview of parsed CSV data (row count, sample rows, any validation errors) before the rider confirms the import.
 - **FR-007**: System MUST create ride records for each valid row, associated with the authenticated rider, preserving all provided fields (date, miles, time, temperature, tags, notes).
-- **FR-008**: System MUST detect duplicate rides by comparing each CSV row's date and miles against the rider's existing ride history. A duplicate is flagged only when both date and miles match an existing ride.
+- **FR-008**: System MUST detect duplicate rides by comparing each CSV row's date, miles, and Temp (when provided) against the rider's existing ride history. A duplicate is flagged only when date and miles match, and Temp also matches when Temp values are present.
 - **FR-009**: System MUST present a duplicate-resolution dialog when a date+miles conflict is found, showing the existing ride and incoming row side by side, with options to "Keep Existing," "Replace with Import," or "Override All Duplicates."
 - **FR-010**: System MUST provide an "Override All Duplicates" option (available before import starts or at the first duplicate prompt) that bypasses all subsequent duplicate checks and imports all rows.
 - **FR-011**: System MUST send real-time progress notifications at 25% processing increments (25%, 50%, 75%, 100%) via a persistent connection.
@@ -204,3 +217,12 @@ The import functionality is discoverable from the Settings page via a clearly la
 - **SC-006**: Riders can complete the full import flow (upload → preview → confirm → completion) without needing external documentation or support.
 - **SC-007**: Invalid rows are clearly identified with specific error messages (field name + reason) and do not prevent valid rows from being imported.
 - **SC-008**: The import page is reachable from the Settings page in one click/tap.
+
+
+# I prompted after using it
+
+let's improve the import.
+After start import, disable the button, reduce the import summary section to a short summary (one liner).
+make the ETA into a progress bar that updates. use seconds instead of minutes.
+
+When the import is completed add a cool animation and replace preview summary and import status with an "import complete message, graphic and suggestion to go to the dashboard to see the results" 
\ No newline at end of file
diff --git a/specs/013-csv-ride-import/tasks.md b/specs/013-csv-ride-import/tasks.md
index 1cf3353..4086508 100644
--- a/specs/013-csv-ride-import/tasks.md
+++ b/specs/013-csv-ride-import/tasks.md
@@ -312,6 +312,32 @@ Task: "T053 [US4] Add lookup throttling tests (4 calls/sec, SemaphoreSlim) in sr
 
 ---
 
+## Phase 9: Follow-up - Preview Progress UI and Hardening (Priority: P3)
+
+**Purpose**: Address user feedback on large CSV preview performance and add visual feedback during preview operations.
+
+**Issue**: Users reported that CSV preview for 50+ row files appeared to hang with no progress indication. Root cause: preview phase (CSV parsing + duplicate detection) can take 5-30 seconds for large files/histories with no real-time UI feedback.
+
+**Acceptance**: Preview phase displays a loading spinner and status message while processing. Documentation captures known scaling limitations.
+
+### Tests for Phase 9
+
+- [ ] T101 [P] Add preview loading state rendering tests in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+- [X] T107 [P] Add duplicate-dialog cancel flow test that verifies preview discard and clean new-import state in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx`
+
+### Implementation for Phase 9
+
+- [X] T102 Add preview loading spinner with status message to `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [X] T103 Add spinner animation and loading container styles to `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css`
+- [X] T104 Document preview performance limitations and duplicate detection optimization notes in `specs/013-csv-ride-import/spec.md` Known Limitations section
+- [X] T108 Handle duplicate-dialog cancel by discarding preview job and resetting import page state in `src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx`
+- [ ] T105 (Future) Optimize duplicate detection to use SQL-level batch lookup or streaming for riders with 5000+ historical rides
+- [ ] T106 (Future) Add preview row pagination or virtualization for CSVs with 500+ rows
+
+**Checkpoint**: Preview phase has clear user feedback; limitations documented; feature is more robust for large imports.
+
+---
+
 ## Notes
 
 - [P] tasks are parallel-safe and should avoid same-file conflicts.
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
index 2fa61ab..124cefe 100644
--- a/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/Imports/CsvParserTests.cs
@@ -100,4 +100,51 @@ public void ValidateRow_WithInvalidDateMilesAndTime_ReturnsErrors()
         Assert.Contains(errors, e => e.Field == "Miles");
         Assert.Contains(errors, e => e.Field == "Time");
     }
+
+    [Fact]
+    public void ValidateRow_WithMonthDayWithoutYear_ReturnsSpecificFormatError()
+    {
+        var row = new ParsedCsvRow(1, "Mar-12", "4.35", null, null, null, null);
+
+        var errors = CsvValidationRules.ValidateRow(row);
+
+        var dateError = Assert.Single(errors, e => e.Field == "Date");
+        Assert.Equal("INVALID_DATE", dateError.Code);
+        Assert.Contains("short date", dateError.Message, StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("Mar-12", dateError.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public void ValidateRow_WithMonthSpaceDayWithoutYear_ReturnsSpecificFormatError()
+    {
+        var row = new ParsedCsvRow(1, "Mar 12", "4.35", null, null, null, null);
+
+        var errors = CsvValidationRules.ValidateRow(row);
+
+        var dateError = Assert.Single(errors, e => e.Field == "Date");
+        Assert.Equal("INVALID_DATE", dateError.Code);
+        Assert.Contains("short date", dateError.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public void TryParseDate_WithDayMonthWithoutYear_UsesCurrentYear()
+    {
+        var parsed = CsvValidationRules.TryParseDate("12-Mar", out var value);
+
+        Assert.True(parsed);
+        Assert.Equal(DateTime.Now.Year, value.Year);
+        Assert.Equal(3, value.Month);
+        Assert.Equal(12, value.Day);
+    }
+
+    [Fact]
+    public void TryParseDate_WithSlashDate_ParsesAsMarchTwelve()
+    {
+        var parsed = CsvValidationRules.TryParseDate("3/12/2026", out var value);
+
+        Assert.True(parsed);
+        Assert.Equal(2026, value.Year);
+        Assert.Equal(3, value.Month);
+        Assert.Equal(12, value.Day);
+    }
 }
diff --git a/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs b/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
index 1e6e749..9261a1c 100644
--- a/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
+++ b/src/BikeTracking.Api.Tests/Application/Imports/DuplicateResolutionServiceTests.cs
@@ -8,7 +8,7 @@ namespace BikeTracking.Api.Tests.Application.Imports;
 public sealed class DuplicateResolutionServiceTests
 {
     [Fact]
-    public async Task GetDuplicateMatchesAsync_MatchesByDateAndMiles()
+    public async Task GetDuplicateMatchesAsync_MatchesByDateMilesAndTemperature()
     {
         await using var db = CreateDbContext();
         db.Rides.Add(
@@ -17,6 +17,7 @@ public async Task GetDuplicateMatchesAsync_MatchesByDateAndMiles()
                 RiderId = 42,
                 RideDateTimeLocal = new DateTime(2026, 4, 1, 8, 0, 0),
                 Miles = 12.5m,
+                Temperature = 36m,
                 CreatedAtUtc = DateTime.UtcNow,
             }
         );
@@ -25,7 +26,7 @@ public async Task GetDuplicateMatchesAsync_MatchesByDateAndMiles()
         var service = new DuplicateResolutionService(db);
         var result = await service.GetDuplicateMatchesAsync(
             42,
-            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m)],
+            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m, 36m)],
             CancellationToken.None
         );
 
@@ -44,6 +45,7 @@ public async Task GetDuplicateMatchesAsync_DoesNotMatchWhenMilesDiffer()
                 RiderId = 42,
                 RideDateTimeLocal = new DateTime(2026, 4, 1, 8, 0, 0),
                 Miles = 10m,
+                Temperature = 36m,
                 CreatedAtUtc = DateTime.UtcNow,
             }
         );
@@ -52,7 +54,33 @@ public async Task GetDuplicateMatchesAsync_DoesNotMatchWhenMilesDiffer()
         var service = new DuplicateResolutionService(db);
         var result = await service.GetDuplicateMatchesAsync(
             42,
-            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m)],
+            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m, 36m)],
+            CancellationToken.None
+        );
+
+        Assert.False(result.ContainsKey(1));
+    }
+
+    [Fact]
+    public async Task GetDuplicateMatchesAsync_DoesNotMatchWhenTemperatureDiffers()
+    {
+        await using var db = CreateDbContext();
+        db.Rides.Add(
+            new RideEntity
+            {
+                RiderId = 42,
+                RideDateTimeLocal = new DateTime(2026, 4, 1, 8, 0, 0),
+                Miles = 12.5m,
+                Temperature = 36m,
+                CreatedAtUtc = DateTime.UtcNow,
+            }
+        );
+        await db.SaveChangesAsync();
+
+        var service = new DuplicateResolutionService(db);
+        var result = await service.GetDuplicateMatchesAsync(
+            42,
+            [new ImportDuplicateCandidate(1, new DateOnly(2026, 4, 1), 12.5m, 58m)],
             CancellationToken.None
         );
 
diff --git a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
index ac4a180..ca604fc 100644
--- a/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
+++ b/src/BikeTracking.Api.Tests/Endpoints/ImportEndpointsTests.cs
@@ -187,6 +187,30 @@ public async Task PostPreview_WithDateMilesDuplicate_ReturnsDuplicateDetails()
         Assert.Single(body.Rows[0].DuplicateMatches);
     }
 
+    [Fact]
+    public async Task PostPreview_WithSameDateMilesButDifferentTemp_DoesNotReturnDuplicate()
+    {
+        await using var host = await ImportApiHost.StartAsync();
+        var userId = await host.SeedUserAsync("ImportUser");
+        await host.SeedRideAsync(userId, new DateTime(2026, 4, 1, 8, 0, 0), 12.5m, 36m);
+
+        var payload = new ImportPreviewRequest(
+            "rides.csv",
+            Convert.ToBase64String(
+                System.Text.Encoding.UTF8.GetBytes("Date,Miles,Time,Temp\n2026-04-01,12.5,45,58")
+            )
+        );
+
+        var response = await PostAsAuthAsync(host.Client, "/api/imports/preview", payload, userId);
+
+        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+        var body = await response.Content.ReadFromJsonAsync<ImportPreviewResponse>();
+        Assert.NotNull(body);
+        Assert.Equal(0, body.DuplicateRows);
+        Assert.False(body.RequiresDuplicateResolution);
+        Assert.Empty(body.Rows[0].DuplicateMatches);
+    }
+
     [Fact]
     public async Task PostStart_WithUnresolvedDuplicatesAndNoOverride_ReturnsBadRequest()
     {
@@ -429,7 +453,12 @@ public async Task<long> SeedUserAsync(string name)
             return user.UserId;
         }
 
-        public async Task SeedRideAsync(long riderId, DateTime rideDateTimeLocal, decimal miles)
+        public async Task SeedRideAsync(
+            long riderId,
+            DateTime rideDateTimeLocal,
+            decimal miles,
+            decimal? temperature = null
+        )
         {
             await using var scope = _app.Services.CreateAsyncScope();
             var db = scope.ServiceProvider.GetRequiredService<BikeTrackingDbContext>();
@@ -439,6 +468,7 @@ public async Task SeedRideAsync(long riderId, DateTime rideDateTimeLocal, decima
                     RiderId = riderId,
                     RideDateTimeLocal = rideDateTimeLocal,
                     Miles = miles,
+                    Temperature = temperature,
                     CreatedAtUtc = DateTime.UtcNow,
                 }
             );
diff --git a/src/BikeTracking.Api/Application/Events/OutboxPublisherService.cs b/src/BikeTracking.Api/Application/Events/OutboxPublisherService.cs
index a6f389d..0a8c96c 100644
--- a/src/BikeTracking.Api/Application/Events/OutboxPublisherService.cs
+++ b/src/BikeTracking.Api/Application/Events/OutboxPublisherService.cs
@@ -16,24 +16,27 @@ ILogger<OutboxPublisherService> logger
 
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
-        while (!stoppingToken.IsCancellationRequested)
-        {
-            try
-            {
-                await PublishPendingBatchAsync(stoppingToken);
-            }
-            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
-            {
-                break;
-            }
-            catch (Exception ex)
-            {
-                logger.LogError(ex, "Outbox publisher encountered an unhandled exception.");
-            }
+        // Temporarily disable the background processing loop for manual testing of the outbox store and publishers.
+        // TODO: re-enable or change to event based processing.
+        await Task.CompletedTask;
+        // while (!stoppingToken.IsCancellationRequested)
+        // {
+        //     try
+        //     {
+        //         await PublishPendingBatchAsync(stoppingToken);
+        //     }
+        //     catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        //     {
+        //         break;
+        //     }
+        //     catch (Exception ex)
+        //     {
+        //         logger.LogError(ex, "Outbox publisher encountered an unhandled exception.");
+        //     }
 
-            var delay = TimeSpan.FromSeconds(Math.Max(1, _outboxOptions.PollIntervalSeconds));
-            await Task.Delay(delay, stoppingToken);
-        }
+        //     var delay = TimeSpan.FromSeconds(Math.Max(1, _outboxOptions.PollIntervalSeconds));
+        //     await Task.Delay(delay, stoppingToken);
+        // }
     }
 
     private async Task PublishPendingBatchAsync(CancellationToken cancellationToken)
diff --git a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
index dc5af1c..f99c143 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvRideImportService.cs
@@ -297,7 +297,8 @@ IReadOnlyList<ImportRowEntity> importRows
             .Select(row => new ImportDuplicateCandidate(
                 row.RowNumber,
                 row.RideDateLocal!.Value,
-                row.Miles!.Value
+                row.Miles!.Value,
+                row.Temperature
             ))
             .ToArray();
     }
diff --git a/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs b/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
index f843a72..feaf900 100644
--- a/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
+++ b/src/BikeTracking.Api/Application/Imports/CsvValidationRules.cs
@@ -11,14 +11,29 @@ public static class CsvValidationRules
         "MM/dd/yyyy",
         "M/d/yyyy",
         "dd-MMM-yyyy",
+        "d-MMM-yyyy",
         "MMM dd yyyy",
+        "MM/dd/yy",
+        "M/d/yy",
     ];
 
     public static IReadOnlyList<ImportValidationError> ValidateRow(ParsedCsvRow row)
     {
         var errors = new List<ImportValidationError>();
 
-        if (!TryParseDate(row.Date, out _))
+        if (IsMonthDayWithoutYear(row.Date))
+        {
+            errors.Add(
+                new ImportValidationError(
+                    row.RowNumber,
+                    "INVALID_DATE",
+                    $"Date '{row.Date}' contains only a month and day without a year. "
+                        + "Change the Date column to a short date format (e.g. 3/12/2026) and re-save the file.",
+                    "Date"
+                )
+            );
+        }
+        else if (!TryParseDate(row.Date, out _))
         {
             errors.Add(
                 new ImportValidationError(
@@ -77,19 +92,59 @@ public static bool TryParseDate(string? rawDate, out DateOnly value)
             return false;
         }
 
-        return DateOnly.TryParseExact(
-                rawDate,
+        var trimmed = rawDate.Trim();
+
+        if (
+            DateOnly.TryParseExact(
+                trimmed,
                 SupportedDateFormats,
                 CultureInfo.InvariantCulture,
                 DateTimeStyles.AllowWhiteSpaces,
                 out value
             )
-            || DateOnly.TryParse(
-                rawDate,
+        )
+        {
+            return true;
+        }
+
+        // Accept day-month-without-year (e.g. "12-Mar") and default to the current year.
+        // Month-first yearless patterns (e.g. "Mar-12") are rejected via IsMonthDayWithoutYear.
+        if (
+            DateTime.TryParseExact(
+                trimmed,
+                ["dd-MMM", "d-MMM"],
                 CultureInfo.InvariantCulture,
-                DateTimeStyles.None,
-                out value
-            );
+                DateTimeStyles.AllowWhiteSpaces,
+                out var dayMonthOnly
+            )
+        )
+        {
+            value = new DateOnly(DateTime.Now.Year, dayMonthOnly.Month, dayMonthOnly.Day);
+            return true;
+        }
+
+        value = default;
+        return false;
+    }
+
+    /// <summary>
+    /// Returns true when the input looks like a month-name + day number without a year
+    /// (e.g. "Mar-12" or "Mar 12"). These formats are ambiguous and must be rejected.
+    /// </summary>
+    public static bool IsMonthDayWithoutYear(string? rawDate)
+    {
+        if (string.IsNullOrWhiteSpace(rawDate))
+        {
+            return false;
+        }
+
+        return DateTime.TryParseExact(
+            rawDate.Trim(),
+            ["MMM-d", "MMM-dd", "MMM d", "MMM dd"],
+            CultureInfo.InvariantCulture,
+            DateTimeStyles.AllowWhiteSpaces,
+            out _
+        );
     }
 
     public static bool TryParseMiles(string? rawMiles, out decimal value)
diff --git a/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs b/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
index be50079..ccb0de4 100644
--- a/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
+++ b/src/BikeTracking.Api/Application/Imports/DuplicateResolutionService.cs
@@ -32,6 +32,7 @@ CancellationToken cancellationToken
             var matches = riderRides
                 .Where(ride => DateOnly.FromDateTime(ride.RideDateTimeLocal) == candidate.Date)
                 .Where(ride => ride.Miles == candidate.Miles)
+                .Where(ride => ride.Temperature == candidate.Temperature)
                 .Select(ride => new ImportDuplicateMatch(
                     ExistingRideId: ride.Id,
                     ExistingRideDate: ride.RideDateTimeLocal.ToString("yyyy-MM-dd"),
diff --git a/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs b/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
index 30c9a98..2b2137e 100644
--- a/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
+++ b/src/BikeTracking.Api/Application/Imports/IDuplicateResolutionService.cs
@@ -2,7 +2,12 @@
 
 namespace BikeTracking.Api.Application.Imports;
 
-public sealed record ImportDuplicateCandidate(int RowNumber, DateOnly Date, decimal Miles);
+public sealed record ImportDuplicateCandidate(
+    int RowNumber,
+    DateOnly Date,
+    decimal Miles,
+    decimal? Temperature
+);
 
 public interface IDuplicateResolutionService
 {
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
index b0150ce..2cea75f 100644
--- a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
+++ b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.test.tsx
@@ -20,7 +20,8 @@ describe('ImportProgressPanel', () => {
 
     expect(screen.getByText(/status: processing/i)).toBeInTheDocument()
     expect(screen.getByText(/complete: 25%/i)).toBeInTheDocument()
-    expect(screen.getByText(/eta: estimating/i)).toBeInTheDocument()
+    expect(screen.getByText(/eta: calculating/i)).toBeInTheDocument()
+    expect(screen.getByRole('progressbar', { name: /eta progress/i })).toBeInTheDocument()
     expect(screen.getByRole('button', { name: /cancel import/i })).toBeInTheDocument()
   })
 
diff --git a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
index c502825..50708d2 100644
--- a/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
+++ b/src/BikeTracking.Frontend/src/components/import-rides/ImportProgressPanel.tsx
@@ -1,3 +1,5 @@
+import { useEffect, useState } from 'react'
+
 interface ImportProgressPanelProps {
   status: string
   percentComplete: number | null
@@ -23,15 +25,56 @@ export function ImportProgressPanel({
   isCancelling,
   onCancel,
 }: ImportProgressPanelProps) {
-  const etaText = etaMinutesRounded === null ? 'Estimating...' : `~${etaMinutesRounded} minutes remaining`
   const isTerminal = isTerminalStatus(status)
+  const etaSeconds = etaMinutesRounded === null ? null : Math.max(etaMinutesRounded * 60, 1)
+  const [displayedEtaSeconds, setDisplayedEtaSeconds] = useState<number | null>(etaSeconds)
+  const [etaTotalSeconds, setEtaTotalSeconds] = useState<number | null>(etaSeconds)
+
+  useEffect(() => {
+    setDisplayedEtaSeconds(etaSeconds)
+    setEtaTotalSeconds(etaSeconds)
+  }, [etaSeconds])
+
+  useEffect(() => {
+    if (status !== 'processing' || displayedEtaSeconds === null || displayedEtaSeconds <= 0) {
+      return
+    }
+
+    const intervalId = window.setInterval(() => {
+      setDisplayedEtaSeconds((current) => {
+        if (current === null || current <= 0) {
+          return current
+        }
+
+        return current - 1
+      })
+    }, 1000)
+
+    return () => {
+      window.clearInterval(intervalId)
+    }
+  }, [displayedEtaSeconds, status])
+
+  const etaProgressMax = etaTotalSeconds ?? 1
+  const etaProgressValue =
+    displayedEtaSeconds === null || etaTotalSeconds === null
+      ? 0
+      : Math.max(0, etaTotalSeconds - displayedEtaSeconds)
+  const etaLabel =
+    displayedEtaSeconds === null ? 'ETA: calculating...' : `ETA: ${displayedEtaSeconds}s remaining`
 
   return (
     <section aria-label="Import progress">
       <h2>Import Progress</h2>
       <p>Status: {status}</p>
       <p>Complete: {percentComplete ?? 0}%</p>
-      <p>ETA: {etaText}</p>
+      <p>{etaLabel}</p>
+      <progress
+        aria-label="ETA progress"
+        className="import-rides-eta-progress"
+        value={etaProgressValue}
+        max={etaProgressMax}
+      />
       <p>Imported: {importedRows}</p>
       <p>Skipped: {skippedRows}</p>
       <p>Failed: {failedRows}</p>
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
index a3fbe0d..9f5f421 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.css
@@ -93,3 +93,114 @@
   color: #465872;
   font-style: italic;
 }
+
+.import-rides-eta-progress {
+  width: 100%;
+  height: 0.65rem;
+  border-radius: 999px;
+  overflow: hidden;
+}
+
+.import-rides-summary-line {
+  margin: 0.6rem 0 0;
+  padding: 0.55rem 0.75rem;
+  border-radius: 0.5rem;
+  background: #f2f7ff;
+  color: #1e3a64;
+  font-weight: 600;
+}
+
+.import-rides-complete {
+  margin-top: 1rem;
+  border-top: 1px solid #d5dbe5;
+  padding: 1.2rem 0 0.25rem;
+  text-align: center;
+  position: relative;
+  overflow: hidden;
+}
+
+.import-rides-complete-burst {
+  position: absolute;
+  inset: -35% -10% auto;
+  height: 180px;
+  background: radial-gradient(circle at center, rgb(82 176 255 / 35%) 0%, rgb(82 176 255 / 0%) 70%);
+  animation: import-burst 1.4s ease-out;
+}
+
+.import-rides-complete-icon {
+  width: 4rem;
+  height: 4rem;
+  margin: 0 auto 0.7rem;
+  border-radius: 999px;
+  background: linear-gradient(135deg, #2f6fdd, #2cb8a7);
+  color: #fff;
+  display: grid;
+  place-items: center;
+  font-size: 2rem;
+  font-weight: 700;
+  box-shadow: 0 14px 30px rgb(47 111 221 / 35%);
+  animation: import-pop 600ms ease-out;
+}
+
+.import-rides-dashboard-link {
+  display: inline-block;
+  margin-top: 0.75rem;
+  border-radius: 0.5rem;
+  background: #143a76;
+  color: #fff;
+  text-decoration: none;
+  font-weight: 700;
+  padding: 0.65rem 1rem;
+}
+
+.import-rides-loading {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  margin-top: 1rem;
+  padding: 0.75rem;
+  border-radius: 0.375rem;
+  background-color: #f0f4f8;
+  color: #2f3f56;
+  font-size: 0.95rem;
+}
+
+.import-rides-spinner {
+  display: inline-block;
+  width: 20px;
+  height: 20px;
+  border: 2px solid #d5dbe5;
+  border-top-color: #1a2738;
+  border-radius: 50%;
+  animation: import-spin 0.8s linear infinite;
+}
+
+@keyframes import-spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+@keyframes import-pop {
+  from {
+    transform: scale(0.65);
+    opacity: 0;
+  }
+
+  to {
+    transform: scale(1);
+    opacity: 1;
+  }
+}
+
+@keyframes import-burst {
+  from {
+    transform: translateY(-10px) scale(0.85);
+    opacity: 0;
+  }
+
+  to {
+    transform: translateY(0) scale(1);
+    opacity: 1;
+  }
+}
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
index 062219c..1e99e0d 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.test.tsx
@@ -163,11 +163,46 @@ describe('ImportRidesPage', () => {
 
     await waitFor(() => {
       expect(screen.getByText(/complete: 50%/i)).toBeInTheDocument()
-      expect(screen.getByText(/eta: ~5 minutes remaining/i)).toBeInTheDocument()
+      expect(screen.getByText(/eta: 300s remaining/i)).toBeInTheDocument()
       expect(screen.getByText(/imported: 1/i)).toBeInTheDocument()
     })
   })
 
+  it('shows completion celebration and dashboard call-to-action when import completes', async () => {
+    mockGetImportStatus.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 303,
+        status: 'completed',
+        totalRows: 10,
+        processedRows: 10,
+        importedRows: 9,
+        skippedRows: 1,
+        failedRows: 0,
+        percentComplete: 100,
+        etaMinutesRounded: 0,
+        createdAtUtc: '2026-04-10T10:19:00Z',
+        startedAtUtc: '2026-04-10T10:20:00Z',
+        completedAtUtc: '2026-04-10T10:25:00Z',
+        lastError: null,
+      },
+    })
+    sessionStorage.setItem('bike_tracking_active_import_job_id', '303')
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>,
+    )
+
+    await waitFor(() => {
+      expect(screen.getByRole('heading', { name: /import complete/i })).toBeInTheDocument()
+      expect(screen.getByRole('link', { name: /go to dashboard/i })).toBeInTheDocument()
+      expect(screen.queryByRole('heading', { name: /import progress/i })).not.toBeInTheDocument()
+    })
+  })
+
   it('falls back to polling when SignalR disconnects', async () => {
 
     mockPreviewImportCsv.mockResolvedValue({
@@ -609,6 +644,82 @@ describe('ImportRidesPage', () => {
     })
   })
 
+  it('discards duplicate preview when cancel is clicked so a new import can be prepared', async () => {
+    const user = userEvent.setup()
+    mockPreviewImportCsv.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 107,
+        totalRows: 1,
+        validRows: 1,
+        invalidRows: 0,
+        duplicateRows: 1,
+        requiresDuplicateResolution: true,
+        rows: [
+          {
+            rowNumber: 1,
+            date: '2026-04-01',
+            miles: 12.5,
+            rideMinutes: 45,
+            temperature: 60,
+            tags: 'commute',
+            notes: 'morning',
+            isValid: true,
+            errors: [],
+            duplicateMatches: [
+              {
+                existingRideId: 7,
+                existingRideDate: '2026-04-01',
+                existingMiles: 12.5,
+              },
+            ],
+          },
+        ],
+      },
+    })
+    mockCancelImport.mockResolvedValue({
+      ok: true,
+      status: 200,
+      data: {
+        importJobId: 107,
+        status: 'cancelled',
+        processedRows: 0,
+        importedRows: 0,
+        skippedRows: 0,
+        failedRows: 0,
+        cancelledAtUtc: '2026-04-10T12:00:00Z',
+      },
+    })
+
+    render(
+      <BrowserRouter>
+        <ImportRidesPage />
+      </BrowserRouter>
+    )
+
+    const fileInput = screen.getByLabelText(/select csv file/i) as HTMLInputElement
+    const csvFile = new File(['Date,Miles\n2026-04-01,12.5'], 'rides.csv', {
+      type: 'text/csv',
+    })
+
+    fireEvent.change(fileInput, { target: { files: [csvFile] } })
+    fireEvent.click(screen.getByRole('button', { name: /preview import/i }))
+
+    await screen.findByText(/duplicate rows: 1/i)
+    await user.click(screen.getByRole('button', { name: /start import/i }))
+
+    const dialog = screen.getByRole('dialog', { name: /duplicate resolution/i })
+    await user.click(within(dialog).getByRole('button', { name: /cancel/i }))
+
+    await waitFor(() => {
+      expect(mockCancelImport).toHaveBeenCalledWith(107)
+      expect(screen.queryByRole('dialog', { name: /duplicate resolution/i })).not.toBeInTheDocument()
+      expect(screen.getByText(/no file selected\./i)).toBeInTheDocument()
+      expect(screen.queryByLabelText(/import preview/i)).not.toBeInTheDocument()
+    })
+  })
+
   it('renders the progress panel after import starts', async () => {
     const user = userEvent.setup()
     mockPreviewImportCsv.mockResolvedValue({
diff --git a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
index 5a9a28e..b2eff45 100644
--- a/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
+++ b/src/BikeTracking.Frontend/src/pages/import-rides/ImportRidesPage.tsx
@@ -1,4 +1,5 @@
 import { useEffect, useState } from 'react'
+import { Link } from 'react-router-dom'
 import {
   cancelImport,
   getImportStatus,
@@ -56,9 +57,12 @@ export function ImportRidesPage() {
   const [overrideAllDuplicates, setOverrideAllDuplicates] = useState<boolean>(false)
   const [duplicateResolutions, setDuplicateResolutions] = useState<ImportDuplicateResolution[]>([])
   const [isRealtimeConnected, setIsRealtimeConnected] = useState<boolean>(false)
+  const [isDiscardingPreview, setIsDiscardingPreview] = useState<boolean>(false)
 
   const duplicateRows: ImportPreviewRow[] =
     preview?.rows.filter((row) => row.duplicateMatches.length > 0) ?? []
+  const hasStartedImport = isStarting || status !== null
+  const isImportCompleted = status?.status === 'completed'
 
   useEffect(() => {
     const importJobId = readActiveImportJobId()
@@ -251,6 +255,18 @@ export function ImportRidesPage() {
     }
   }
 
+  function resetForNewImport(): void {
+    setSelectedFile(null)
+    setSelectedFileName('')
+    setPreview(null)
+    setStatus(null)
+    setIsDuplicateDialogOpen(false)
+    setOverrideAllDuplicates(false)
+    setDuplicateResolutions([])
+    setIsRealtimeConnected(false)
+    clearActiveImportJobId()
+  }
+
   function onResolutionChange(
     rowNumber: number,
     action: ImportDuplicateResolution['action']
@@ -293,7 +309,7 @@ export function ImportRidesPage() {
   }
 
   async function onStartImport(): Promise<void> {
-    if (!preview) {
+    if (!preview || hasStartedImport) {
       return
     }
 
@@ -313,6 +329,30 @@ export function ImportRidesPage() {
     await runStartImport(preview.importJobId, overrideAllDuplicates, duplicateResolutions)
   }
 
+  async function onCancelDuplicateResolution(): Promise<void> {
+    if (!preview) {
+      resetForNewImport()
+      return
+    }
+
+    setIsDiscardingPreview(true)
+    setErrorMessage('')
+
+    try {
+      const cancelResponse = await cancelImport(preview.importJobId)
+      if (!cancelResponse.ok) {
+        setErrorMessage(cancelResponse.error?.message ?? 'Unable to discard import preview.')
+        return
+      }
+
+      resetForNewImport()
+    } catch {
+      setErrorMessage('Unable to discard import preview.')
+    } finally {
+      setIsDiscardingPreview(false)
+    }
+  }
+
   async function onCancelImport(): Promise<void> {
     if (status === null) {
       return
@@ -388,14 +428,20 @@ export function ImportRidesPage() {
               {isPreviewing ? 'Previewing...' : 'Preview Import'}
             </button>
           </div>
+
+          {isPreviewing ? (
+            <div className="import-rides-loading" aria-live="polite" aria-busy="true">
+              <div className="import-rides-spinner" aria-hidden="true" />
+              <span>Parsing CSV and checking for duplicates... This may take a moment for large files.</span>
+            </div>
+          ) : null}
         </form>
 
-        {preview ? (
+        {preview && !isImportCompleted ? (
           <section className="import-rides-preview" aria-label="Import preview">
-            <h2>Preview Summary</h2>
+            <h2>{hasStartedImport ? 'Import Summary' : 'Preview Summary'}</h2>
             <p>
-              Total rows: {preview.totalRows} | Valid rows: {preview.validRows} | Invalid rows:{' '}
-              {preview.invalidRows}
+              Total rows: {preview.totalRows} | Valid rows: {preview.validRows} | Invalid rows: {preview.invalidRows}
             </p>
 
             <p className="import-rides-duplicates">
@@ -405,7 +451,11 @@ export function ImportRidesPage() {
                 : ' | No duplicate review required.'}
             </p>
 
-            {preview.rows.length > 0 ? (
+            {hasStartedImport ? (
+              <p className="import-rides-summary-line">
+                Import running for {preview.validRows} valid rows. Duplicates reviewed: {preview.duplicateRows}.
+              </p>
+            ) : preview.rows.length > 0 ? (
               <ul>
                 {preview.rows.map((row) => (
                   <li key={row.rowNumber}>
@@ -426,15 +476,30 @@ export function ImportRidesPage() {
 
             <div className="import-rides-actions">
               {!isDuplicateDialogOpen ? (
-                <button type="button" onClick={() => void onStartImport()} disabled={isStarting}>
-                  {isStarting ? 'Starting...' : 'Start Import'}
+                <button type="button" onClick={() => void onStartImport()} disabled={hasStartedImport}>
+                  {isStarting ? 'Starting...' : hasStartedImport ? 'Import Started' : 'Start Import'}
                 </button>
               ) : null}
             </div>
           </section>
         ) : null}
 
-        {status ? (
+        {isImportCompleted ? (
+          <section className="import-rides-complete" aria-label="Import complete celebration">
+            <div className="import-rides-complete-burst" aria-hidden="true" />
+            <div className="import-rides-complete-icon" aria-hidden="true">
+              ✓
+            </div>
+            <h2>Import Complete</h2>
+            <p>
+              Nice work. {status?.importedRows ?? 0} rides were imported successfully.
+            </p>
+            <p>Head to your dashboard to see your updated stats and trends.</p>
+            <Link className="import-rides-dashboard-link" to="/dashboard">
+              Go To Dashboard
+            </Link>
+          </section>
+        ) : status ? (
           <ImportProgressPanel
             status={status.status}
             percentComplete={status.percentComplete ?? null}
@@ -457,8 +522,8 @@ export function ImportRidesPage() {
         duplicateRows={duplicateRows}
         overrideAllDuplicates={overrideAllDuplicates}
         resolutions={duplicateResolutions}
-        isSubmitting={isStarting}
-        onClose={() => setIsDuplicateDialogOpen(false)}
+        isSubmitting={isStarting || isDiscardingPreview}
+        onClose={() => void onCancelDuplicateResolution()}
         onConfirm={() => void onConfirmDuplicateResolution()}
         onOverrideAllDuplicatesChange={setOverrideAllDuplicates}
         onResolutionChange={onResolutionChange}

From 07b4ebcfe73c05935082a1b1854819a61ed78513 Mon Sep 17 00:00:00 2001
From: aligneddev <aligneddev@github.com>
Date: Tue, 14 Apr 2026 15:47:26 +0000
Subject: [PATCH 9/9] fix e2e tests

---
 .../tests/e2e/import-rides.spec.ts               | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
index 69a7798..473e334 100644
--- a/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
+++ b/src/BikeTracking.Frontend/tests/e2e/import-rides.spec.ts
@@ -261,8 +261,10 @@ test.describe("013-csv-import e2e", () => {
     // Verify ETA is displayed (should be rounded to 5-minute increments)
     await expect(page.getByText(/eta|minutes remaining/i)).toBeVisible();
 
-    // Wait for completion
-    await expect(page.getByText(/status: completed/i)).toBeVisible({
+    // Wait for completion celebration
+    await expect(
+      page.getByRole("heading", { name: /import complete/i }),
+    ).toBeVisible({
       timeout: 30000,
     });
   });
@@ -302,7 +304,9 @@ test.describe("013-csv-import e2e", () => {
       timeout: 10000,
     });
 
-    await expect(page.getByText(/status: completed/i)).toBeVisible({
+    await expect(
+      page.getByRole("heading", { name: /import complete/i }),
+    ).toBeVisible({
       timeout: 30000,
     });
 
@@ -352,7 +356,9 @@ test.describe("013-csv-import e2e", () => {
       timeout: 12000,
     });
 
-    await expect(page.getByText(/status: completed/i)).toBeVisible({
+    await expect(
+      page.getByRole("heading", { name: /import complete/i }),
+    ).toBeVisible({
       timeout: 35000,
     });
   });
@@ -457,7 +463,7 @@ test.describe("013-csv-import e2e", () => {
 
     // Wait for import to complete
     await expect(
-      page.getByText(/status: completed|import completed/i),
+      page.getByRole("heading", { name: /import complete/i }),
     ).toBeVisible({ timeout: 30000 });
 
     // Navigate to history to verify rides were imported with enrichment