Go LLM Interactive Proxy

Go LLM Interactive Proxy (LIP) is a streaming-first control plane for LLM traffic. It sits between AI clients and provider backends so operators can keep client integrations stable while changing routing, provider mix, resilience behavior, observability, and extension policy at the proxy layer.

The standard distribution, cmd/lipstd, serves bundled HTTP frontends, routes through canonical lipapi requests and event streams, and wires the official backends and feature plugins through explicit registration.

What it does

• Multi-protocol frontends - OpenAI Responses, legacy OpenAI-compatible chat, Anthropic Messages, and Gemini generateContent-compatible HTTP surfaces.
• Backend flexibility - hosted provider adapters, OpenAI-compatible/local runtimes, agent-specific backends, custom-compatible backend rows, and a no-key localstub backend for dogfood.
• Canonical translation - frontend and backend adapters translate through one protocol-neutral request model and event stream; no pairwise protocol translators.
• Core-owned routing - ordered failover, weighted routing, parallel races, TTFT budgets, model aliases, route diagnostics, and circuit-breaker eligibility live in the core.
• Continuity and recovery - B2BUA-style A-leg/B-leg lineage records recoverable pre-output attempts, while post-output failures are surfaced instead of silently retried.
• Operator hardening - typed config, auth/access modes, secure sessions, diagnostics secrets, pprof controls, Prometheus metrics, OpenTelemetry tracing, access logs, and resource limits.
• Extension platform - feature bundles use pkg/lipsdk facades for request shaping, tools, completion gates, workspace/state, traffic observation, auxiliary calls, and compatibility hooks.
• Canonical reload contract - Explicit SIGHUP/management-API reload through pkg/lipsdk/configreload (no watcher; DTOs never carry paths, credentials, or raw YAML). This is the one reload contract beside one process runtime / ProcessServices, one generation runtime, and one private-field host (runtimebundle.BuildHost / Host.Close). check-config validates without publishing a generation. Operator contract: docs/runtime-config-reload.md.
• Accounting and dual-plane economics - Optional metering journal and authority stores. Post-turn billing rates sealed usage records; the runtime never enriches stream-time prices. Rollout: docs/dual-plane-rollout.md. Billing injection: docs/billing-host-composition.md. Feature gates: docs/release-gates.md.
• Public production facade - pkg/lipruntime builds the standard distribution without importing internal/. Public lipruntime.Options uses RequestRegistrations / AttemptRegistrations / ConcurrencyRegistration only. Supported methods: Build, ExecutorView, Ready, Capabilities, MeteringQuerier, ReadinessReport, RefreshSnapshots, Reload, ReloadStatus, ReloadControl, Close. Field map: docs/legacy-options-migration.md.

Standard distribution

Hybrid backends (ADR 0008): essential kinds are code-owned by internal/standardplugins (EssentialBackendBundle / tables in standard_table.go); optional connectors are executable plugins under connectors/ via closed manifests. Mandatory distribution subset is in pkg/lipsdk/standard_bundle.go.

Surface	Bundled support
Frontends	openai-responses, openai-legacy, anthropic, gemini
Hosted/provider backends	Built-in: openai-responses, openai-legacy, anthropic, gemini, bedrock. External plugins: acp family, openrouter, nvidia, huggingface, opencode-go/opencode-zen (connectors/opencode one artifact), openai-codex/openai-codex-app-server (connectors/codex one artifact)
Local / compatible backends	External: ollama, ollama-cloud, llamacpp, lmstudio, vllm, local-stub. Built-in: custom OpenAI/Anthropic-compatible kinds — see docs/custom-compatible-backends.md
Local-agent / experimental	External cursorcliacp connector; experimental external cursorsdk connector (Node bridge-node over @cursor/sdk 1.0.23) discovered via closed manifest — see docs/cursor-sdk-backend.md
Feature plugins	no-op compatibility hooks plus reference/proof plugins for submit, parts, tools, workspace guard, traffic transcript, verifier, pre-request policy, auto-append, and Codex client compatibility; standard distro also default-enables canonical tool-call-repair (ADR 0007; opt out with enabled: false)

Quick start

Start with the no-key local stub path when you want to validate config, routing, inventory, and HTTP serving without hosted provider credentials. local-stub is an external connector (connectors/localstub); stage it before using the example config:

make package-full PACKAGE_DEST=.golip-plugins
go run ./cmd/lipstd check-config --config ./config/examples/dogfood-local-stub.yaml
go run ./cmd/lipstd routes --config ./config/examples/dogfood-local-stub.yaml
go run ./cmd/lipstd inventory --config ./config/examples/dogfood-local-stub.yaml
go run ./cmd/lipstd inspect --config ./config/examples/dogfood-local-stub.yaml
go run ./cmd/lipstd doctor --config ./config/examples/dogfood-local-stub.yaml --instance dogfood-local
go run ./cmd/lipstd serve --config ./config/examples/dogfood-local-stub.yaml

inspect reports built-in/discovered/configured plugin states without launching processes. doctor --instance <id> may launch only that configured backend instance for secure-channel checks (never all discovered plugins; no connector credentials after peer/channel failure). Optional plugins.backend_discovery configures trusted discovery roots (enabled, paths, strict, development_mode).

For hosted providers, use config/config.yaml as the sample and provide API keys through YAML or environment variables. standardplugins.ResolveUpstreamAPIKeysFromEnv resolves the supported provider env vars and numbered variants once at startup; see internal/standardplugins/keys.go for the exact names and numbering rules.

go run ./cmd/lipstd --config ./config/config.yaml

Releases and installation

Prebuilt lipstd binaries for Linux, macOS, and Windows (amd64 and arm64) are published through GitHub Releases when a semantic version tag (vX.Y.Z) is pushed. Each release includes platform archives (.tar.gz on Linux/macOS, .zip on Windows), checksums.txt (SHA-256), and build-provenance attestations.

After downloading an archive for your OS/architecture:

# Linux/macOS example
tar -xzf go-llm-interactive-proxy_vX.Y.Z_linux_amd64.tar.gz
./lipstd --version
./lipstd check-config --config ./config/config.yaml

Verify the archive checksum against checksums.txt before use. Connector plugins remain separate installable artifacts; see docs/backend-plugins/operator.md.

License: This repository does not currently ship an owner-approved open-source license. Public redistribution rights remain undefined until one is added.

Repository file policy

Every tracked file must match an approved path pattern or exact entry in .release-files. The manifest uses pattern wildcards (.kiro/**, .agents/**, docs/**, internal/**, pkg/**) to cover specifications, agent skills, documentation, and package trees without requiring individual file enumeration for spec authors or document creators.

The manifest is enforced locally and in CI (Repo hygiene):

bash scripts/check-release-clean.sh          # working tree
bash scripts/check-release-clean.sh --staged   # staged index (pre-commit)
bash scripts/check-release-clean.sh --ref HEAD # specific revision

Install versioned Git hooks (manifest check on commit/push, plus the 100-file change-size gate):

bash scripts/setup-hooks.sh

Commits and PRs may not change more than 100 files. Override with LIP_ALLOW_LARGE_CHANGE=1, git config lip.allowLargeChange true, or the allow-large-change PR label. scripts/check-change-size.sh (or scripts/check-change-size.ps1) is the same checker the hooks and CI run.

New top-level files or new component directories must be covered by patterns or entries in .release-files in the same commit. CI never auto-updates the manifest.

lipstd accepts --config before or after the subcommand; if it appears more than once, the later value wins. See docs/dogfood-local.md for the full local dogfood flow. Truncated tool-call repair can be exercised with config/examples/dogfood-tool-call-repair.yaml (see ADR docs/adr/0007-canonical-tool-call-repair.md).

Configuration and operations

• Config - Runtime config is typed and loaded from YAML. config/config.yaml documents access/auth templates, server timeouts (including server.shutdown_timeout), inbound http_headers aliases, logging, diagnostics, observability, routing, continuity, stream-recovery SSE keepalive (stream_recovery.auto_resume.keepalive_interval), identity (A-leg Server / B-leg User-Agent; OpenRouter HTTP attribution for the external openrouter plugin is configured in that connector), and provider rows. See docs/proxy-identity.md. config/config.multi-instance.example.yaml shows multiple backend instances of the same adapter.
• Inbound HTTP header aliases - http_headers appends extra accept names after the bundled defaults (Authorization plus Anthropic x-api-key, Gemini x-goog-api-key, and Azure api-key; X-LIP-Route; session carriers; X-Trace-ID; diagnostics secret). First non-empty value wins, so a default still beats an alias when both are present. Local API-key auth accepts those vendor key headers without extra YAML. Comments in config/config.yaml list every list.
• Billing composition - Billing is host-injected, all-or-none, and has no YAML mode flag. The final flow is settled-credit screen, route/quote, atomic exposure admission, execution without money mutation, durable terminal spool, complete-call gating over every expected B-leg, native customer rating/settlement, and independent provider COGS ordered by (recorded_at, transaction_id). Stock lipstd and public lipruntime.Options remain non-billing. See docs/billing-host-composition.md.
• Routing - Default selectors come from routing.default_route or the first enabled backend plus registry default model ids. model_aliases rewrite full selector strings before parsing. Route selectors support ordered failover, weights, first-request annotations, parallel ! races, per-leg [handicap=N], global/per-leg TTFT budgets, and per-leaf query generation parameters. Route query parameters such as ?reasoning_effort=xhigh and ?verbosity=high are explicit routing directives: when present, they override matching per-request body/canonical generation options; absent parameters leave request values unchanged. Route-wide stickiness is opt-in with {affinity=session} or {affinity=client} (aliases {session_sticky}, {client_sticky}). Interleaved thinking ([thinker] on one weighted branch) is off unless interleaved.enabled is true; interleaved.stream_to_client is hidden (default) or visible. Runtime A-leg routing overrides are opt-in under routing.override_admin (enabled defaults false). When enabled, protected GET/PUT/DELETE at path_prefix (default /admin/routing-overrides/{a_leg_id}) set, replace, inspect, or clear a sticky selector for later turns on that A-leg; in-flight turns keep their snapshotted revision. The admin route is mounted inside the request-plane access-auth stack (API-key/auth middleware plus the diagnostics shared secret). path_prefix must be a literal ServeMux path (braces/{id} wildcards are rejected) and must not overlap other diagnostics or admin mounts. Disabling the HTTP surface does not clear or suspend already-persisted overrides. Non-loopback exposure requires the same diagnostics shared secret as other protected admin surfaces.
• OpenAI Codex verbosity bumps - The openai-codex backend defaults to text.verbosity=high for the first 5 turns of each conversation, and then again on every 10th turn by default, when no explicit per-request verbosity is set. Opt out with early_session_verbosity_bump_disabled: true and/or mid_session_verbosity_bump_disabled: true, or tune with early_session_verbosity_bump_turns / mid_session_verbosity_bump_frequency. When the mid-session bump is disabled, the cadence value is ignored. See docs/openai-codex-backend.md and docs/openai-codex-backend.md.
• Experimental Cursor SDK - Optional local-only cursorsdk connector under connectors/cursorsdk (not in EssentialBackendBundle; manifest-discovered, not root-static). Install the packaged Node bridge-node companion manually (exact @cursor/sdk 1.0.23, Node ≥ 22.13); Go-LIP never runs npm. Use explicit cursorsdk:… routes, separate SDK API-key billing (CURSOR_API_KEY / api_key), and sandbox/settings defaults documented in docs/cursor-sdk-backend.md. Schema example: config/examples/cursor-sdk-experimental.yaml. Offline ACP-vs-SDK matrix: make test-cursor-sdk-comparison-report. cursorcliacp remains a separate external connector.
• Continuity - continuity.store: memory is the default. continuity.store: sqlite with continuity.sqlite_path persists A-leg rows and attempt lineage through internal/core/continuity/sqlitestore. In-memory ttl and max_legs tuning does not apply to SQLite.
• Security - Multi-user or non-loopback deployments need explicit auth/access posture. Local API keys must be at least 16 Unicode code points after trimming. Diagnostics, pprof, metrics, model-catalog diagnostics, and secure-session summaries require a shared secret when exposed beyond loopback. The separate management reload API (POST /admin/config/reload, GET /admin/config/status) is disabled unless LIP_RELOAD_MANAGEMENT_ADDRESS supplies its startup-fixed bind (recommended loopback: 127.0.0.1:9090), so existing starts and multiple local instances do not contend for a hidden fixed port. Its authentication is independent of data-plane cookies or local API keys: explicitly enabled single-user loopback may use documented local trust; multi-user or non-loopback requires LIP_RELOAD_MANAGEMENT_TOKEN (≥16 Unicode code points). When required management settings are absent, management stays disabled with a warning and ordinary data-plane serve continues. Runtime reload is explicit-trigger only (no watcher/auto-retry); see docs/runtime-config-reload.md. On Unix, OpenAI Codex auth.json and managed-OAuth account files must be 0600 (group/other-readable files are now rejected at load); symlinked managed-OAuth account files are skipped. See docs/openai-codex-backend.md. Optional secrets guard (plugins.features id secrets-guard, disabled by default) scans model-bound ingress for loaded secret values only, including JSON object keys and scalar tokens. It does not scan responses/egress or transformed forms; log leaves ingress unchanged, and JSON redact blocks unsupported key/scalar tokens with a normal block decision so quarantine still applies. Multi-user matching uses only the current request credential and safe attribution identifiers. Only one enabled secrets-guard feature instance is supported per deployment, and rollout is staged as disabled -> log -> redact -> block, one action per deployment. See docs/secrets-guard.md and config/examples/secrets-guard-*.yaml.
• Observability - Optional Prometheus metrics and OpenTelemetry tracing are configured under observability. Access logs use bounded-cardinality route groups by default; raw paths are opt-in.
• HTTP clients - The shared upstream client honors HTTP_PROXY / HTTPS_PROXY by default. Set http_client.trust_environment_proxy: false when process environment is not trusted.
• Backend retry posture - The hosted openai-responses, openai-legacy, and anthropic backend factories default sdk_max_retries to 0: retry policy above the HTTP round trip lives in pre-output credential rotation and core failover, not in SDK-transparent retries. Operators may raise sdk_max_retries per backend row to opt back into provider-SDK retries.
• Resource bounds - lipapi.Call.Validate, lipapi.Collect limits, pending wire event caps (max_pending_wire_events; 0 = unlimited), B2BUA store caps, and shared frontend decode admission (max_concurrent_decodes default 32, max_inflight_decode_bytes default 64 MiB) protect memory and request size boundaries. Absolute decompressed body oversize is 413; temporary decode admission saturation is 429 + Retry-After: 1. Admission runs after body ReadAll (bytes already resident) and covers protocol Decode only. Raise body and inflight budgets together for large multimodal / long-context.

More detail: docs/proxy-identity.md, docs/runtime-config-reload.md, docs/secrets-guard.md, docs/database-persistence.md, docs/routing-health-circuit-breaker.md, docs/execerr-classification.md, docs/extension-platform-authoring.md, docs/release-gates.md, and docs/cursor-sdk-backend.md.

Developer workflow

make quality-checks        # gofmt drift, go mod tidy drift, build, vet, guard scripts, archtest
make arch-report           # architecture metrics Markdown; exits non-zero if Req 11.5 net shrinkage fails
make test                  # quality-checks + unit tests + parity-checks
make test-unit             # go test -parallel=8 -timeout=10m ./...
make test-precommit-extra  # precommit-tagged hygiene + executor matrices
make test-fast             # cached guard checks + complete root test graph (safe reverse-dependency coverage)
make parity-checks         # conformance package with -tags=precommit,integration
make test-fuzz             # short fuzz smoke over release-gate fuzz targets
make test-race             # skipped on Windows; strict race runs in nightly CI on Linux
make bench                 # benchmark smoke for hot packages
make pgo-profile           # collect default.pgo from core benches (optional; move under cmd/lipstd)
make pgo-build             # build cmd/lipstd (auto-applies cmd/lipstd/default.pgo when present)
make qa                    # cached fast quality checks + tagged tests + lint + govulncheck + release-gates-static
make isolated-root-qa      # GOWORK=off QA on a temp root copy without connectors/support/Node/artifacts
make installed-plugin-smoke # one lipstd binary; install release artifacts; same-binary inspect/doctor/invoke
make docs-check knowledge-check # backend-plugin docs + steering hybrid consistency
make example-config-check  # operator/example YAML + config/examples bootstrap inspect
make backend-plugin-cross-platform-qa # connector platform matrix compile/package + native lifecycle gates
make backend-plugin-release-gates-static # release report/traceability/wiring (also via make qa)
make backend-plugin-release-gates # full connector/support module matrix + root release suites
make hooks-install         # install optional legacy pre-commit hooks (.githooks)
bash scripts/setup-hooks.sh # install manifest pre-commit/pre-push hooks (recommended)

Operator install/trust/diagnostics/upgrade/rollback for executable backend plugins: docs/backend-plugins/operator.md; threat model / trust equivalence: docs/backend-plugins/threat-model.md (make backend-plugin-security-checks); cross-platform packaging/IPC matrix: make backend-plugin-cross-platform-qa; final release gates: make backend-plugin-release-gates (ADR 0008).

PR CI includes:

• Repo hygiene (.github/workflows/ci.yml) — exact .release-files manifest on every push/PR; cross-platform tests and lipstd build. Linux/macOS run go test -race; Windows runs go test because the ACP PATH-cache stress test is prohibitively slow under the Windows race runtime.
• QA (.github/workflows/qa.yml) — when test-relevant files change: formatting, go mod verify, architecture guardrails, and go vet of cmd/lipstd. Full golangci-lint and govulncheck run locally via make qa / make lint / make vuln; PRs also run govulncheck in .github/workflows/security.yml.
• CodeQL, Go vulnerability check, and OpenSSF Scorecard on main and PRs (where configured).

Nightly CI (.github/workflows/race-fuzz-nightly.yml, also workflow_dispatch) runs strict Linux race and Tier-1 fuzz smoke (FUZZTIME=6s). Locally, make lint runs golangci-lint from PATH (golangci-lint v2; config in .golangci.yml) and falls back to staticcheck. A monthly modernization workflow (.github/workflows/modernize-monthly.yml) re-runs the modernize linter suite and go tool govulncheck.

Recoverability is defined by tests, testdata/ goldens, stable pkg/lipapi / pkg/lipsdk contracts, and steering. Cross-protocol parity: make parity-checks.

Repository layout

• cmd/lipstd/ - standard distribution command and wiring tests.
• pkg/lipapi/ - canonical request, event, capability, validation, and error contracts.
• pkg/lipsdk/ - stable plugin SDK contracts and standard distribution requirements.
  • Compatibility note: FrontendMountOptions gained an optional DecodeAdmission field. Use named composite literals; unkeyed literals that previously listed every field in order will not compile.
  • Compatibility note: pkg/lipsdk/configreload.AllResultCategories (exported mutable var) was replaced by func ResultCategories() []ResultCategory, which returns a defensive copy per call; the pkg/lipruntime.AllResultCategories alias is now a function alias for the same accessor. Readers of the former var must call the function; external assignment is no longer possible.
• internal/core/ - runtime orchestration, routing, continuity, secure sessions, hooks/extensions, stream handling, policy, accounting, config, admin, diagnostics, and safety.
• internal/plugins/ - bundled frontend, essential backend, feature, and protocol-helper packages.
• connectors/, connector-support/ - optional executable backend plugins and shared connector support modules (ADR 0008).
• internal/standardplugins/ - essential/static registration tables, per-backend factory helpers, and InstallStandardBundleOn.
• internal/featurebundle/ - feature merge surface (MergeFeatureSurface over SDK hook slices).
• internal/pluginreg/ - explicit per-composition-root registry and discovered connector registration.
• internal/infra/runtimebundle/ and internal/stdhttp/ - runtime assembly (executor, hook bus, stores) and HTTP mounting/serving.
• internal/infra/ - logging, HTTP client tuning, metrics, tracing, DB, model catalog/registry, routing health, tokenization/accounting, and auth-event plumbing.
• internal/refbackend/, internal/refclient/, internal/testkit/ - emulators, reference clients, fixtures, stubs, and conformance helpers for tests.
• internal/archtest/, internal/qa/, scripts/, .githooks/, .github/workflows/ - guardrails and quality automation.
• docs/ (includes ADR 0008, docs/knowledge knowledge-check), .kiro/, testdata/, config/ - operator docs, steering/spec artifacts, fixtures, and sample configs.

Relationship to Python LIP

This repository is the Go implementation of LIP with a smaller core and explicit plugin/SDK boundaries. The sibling Python project remains useful historical context and migration reference, but Go documentation should describe only behavior implemented in this repo unless a doc explicitly says a feature is Python-era or future migration work.