diff --git a/project/TICKETS.md b/project/TICKETS.md
index 23a289b..1b8d008 100644
--- a/project/TICKETS.md
+++ b/project/TICKETS.md
@@ -84,4 +84,5 @@ of `project/README.md`, which remains a generated technical-analysis artifact.
 | **ticket-104** | [`README.md`](./ticket-104/README.md) | - | - | - | - | - |
 | **ticket-105** | [`README.md`](./ticket-105/README.md) | - | - | - | - | - |
 | **ticket-106** | [`README.md`](./ticket-106/README.md) | - | - | - | - | - |
+| **ticket-108** | [`README.md`](./ticket-108/README.md) | - | - | - | - | - |
 <!-- AUTO:TICKET_INDEX:END -->
diff --git a/project/ticket-110/README.md b/project/ticket-110/README.md
new file mode 100644
index 0000000..9c3ced1
--- /dev/null
+++ b/project/ticket-110/README.md
@@ -0,0 +1,29 @@
+# Ticket 110: Persist and expose base/workspace diagnostics in compare-workspace artifacts (#137)
+
+- **ID**: ticket-110
+- **Owner**: agent:claude
+- **Status**: IN_PROGRESS
+- **Workflow state**: EDIT
+- **Created**: 2026-10-19
+
+## Goal and scope
+
+Closes autogrammar/todo2code#137. `compare-workspace` already reads both runs'
+diagnostics; it now writes them as `base.diagnostics.json` and
+`workspace.diagnostics.json` next to the graphs and lists them as
+`artifacts.baseDiagnostics` / `artifacts.workspaceDiagnostics` (additive).
+Consumers such as the subactor/platform intent gate can stop re-compacting and
+re-diagnosing two 207 MB graphs (subactor/platform#655).
+
+Implementation drafted by Willman (koru.develop_ticket, glm-5.3) and corrected in
+review: the paths go through `artifactPaths` so separators stay normalized.
+
+## Acceptance criteria
+
+- [x] AC-01: Both diagnostics files exist after a comparison and are listed in `artifacts`
+  (`node --test dist/test/workspace.test.js dist/test/cli-compare-workspace.test.js`: 6 pass).
+
+## Tracking boundary
+
+This directory contains the minimal reviewed intent. Optional participant prose
+and raw command logs are not required delivery output.
diff --git a/project/ticket-110/intent.json b/project/ticket-110/intent.json
new file mode 100644
index 0000000..9572ed6
--- /dev/null
+++ b/project/ticket-110/intent.json
@@ -0,0 +1,78 @@
+{
+  "schema": "new-project.intent/v3",
+  "ticket": "ticket-110",
+  "summary": "Persist and expose base/workspace diagnostics in compare-workspace artifacts (#137)",
+  "workstream": "core-dsl",
+  "classification": {
+    "kind": "SERVICE",
+    "priority": "P2",
+    "origin": "health"
+  },
+  "allowedPaths": [
+    "project/ticket-110/**",
+    "TODO.md",
+    "project/TICKETS.md",
+    "src/comparison/workspace.ts",
+    "test/workspace.test.ts",
+    "src/comparison/workspace-trend.ts"
+  ],
+  "forbiddenPaths": [
+    "project/ticket-*/user-*.md"
+  ],
+  "stacks": [],
+  "dependsOn": [],
+  "conflictsWith": [],
+  "integrationTicket": null,
+  "delivery": {
+    "acceptedBaseSha": "a85da84e72c6c3fc7d2ea1c8b6eaf790f972a63f",
+    "targetBranch": "main",
+    "outcome": "compare-workspace persists and exposes base/workspace diagnostics artifacts.",
+    "nonGoals": [
+      "No change to diagnostics content, graphs or existing artifact keys."
+    ],
+    "complexity": "S",
+    "estimatedMinutes": 30,
+    "budgets": {
+      "maxImplementationFiles": 3,
+      "maxAffectedComponents": 1,
+      "maxPublicInterfaceChanges": 1,
+      "maxRuntimeDependencies": 0
+    },
+    "architecture": {
+      "status": "accepted",
+      "decision": "Write the already-loaded diagnostics next to the graphs and add two additive artifact keys via artifactPaths.",
+      "components": [
+        {
+          "name": "comparison",
+          "paths": [
+            "src/comparison/workspace.ts",
+            "src/comparison/workspace-trend.ts",
+            "test/workspace.test.ts"
+          ]
+        }
+      ],
+      "responsibilityChanges": false,
+      "interfaceChanges": [
+        "t2c.workspace-comparison/v1 artifacts: + baseDiagnostics, + workspaceDiagnostics (additive)"
+      ],
+      "dataChanges": [],
+      "ui": {
+        "impact": "none",
+        "states": [],
+        "evidence": []
+      },
+      "rollback": "Revert the commit; consumers fall back to recomputing diagnostics."
+    },
+    "runtimeDependencies": [],
+    "validation": [
+      {
+        "criterion": "AC-01",
+        "commands": [
+          "npm run build",
+          "T2C_USE_SUBLLM=false node --test dist/test/workspace.test.js dist/test/cli-compare-workspace.test.js"
+        ],
+        "evidence": "project/ticket-110/README.md"
+      }
+    ]
+  }
+}
diff --git a/src/comparison/workspace-trend.ts b/src/comparison/workspace-trend.ts
index e527956..d369556 100644
--- a/src/comparison/workspace-trend.ts
+++ b/src/comparison/workspace-trend.ts
@@ -27,6 +27,8 @@ export function artifactPaths(root: string, directory: string): Record<string, s
     comparison: relative('comparison.json'),
     baseGraph: relative('base.graph.json'),
     workspaceGraph: relative('workspace.graph.json'),
+    baseDiagnostics: relative('base.diagnostics.json'),
+    workspaceDiagnostics: relative('workspace.diagnostics.json'),
     baseManifest: relative('base.manifest.json'),
     workspaceManifest: relative('workspace.manifest.json'),
     diffSvg: relative('intent-diff.svg'),
diff --git a/src/comparison/workspace.ts b/src/comparison/workspace.ts
index 29a7718..a56c06e 100644
--- a/src/comparison/workspace.ts
+++ b/src/comparison/workspace.ts
@@ -171,6 +171,8 @@ export async function compareWorkspaceIntent(
       writeJson(path.join(comparisonDirectory, 'comparison.json'), result),
       writeJson(path.join(comparisonDirectory, 'base.graph.json'), baseGraph),
       writeJson(path.join(comparisonDirectory, 'workspace.graph.json'), currentGraph),
+      writeJson(path.join(comparisonDirectory, 'base.diagnostics.json'), baseDiagnostics),
+      writeJson(path.join(comparisonDirectory, 'workspace.diagnostics.json'), currentDiagnostics),
       writeJson(path.join(comparisonDirectory, 'base.manifest.json'), baseRun.manifest),
       writeJson(path.join(comparisonDirectory, 'workspace.manifest.json'), currentRun.manifest),
       writeText(path.join(comparisonDirectory, 'intent-diff.svg'), renderGraphDiffSvg(diff)),
diff --git a/test/workspace.test.ts b/test/workspace.test.ts
index ac5ebca..aaa3413 100644
--- a/test/workspace.test.ts
+++ b/test/workspace.test.ts
@@ -112,6 +112,11 @@ test('workspace comparison measures origin/main against uncommitted filesystem i
   assert.ok(await pathExists(path.join(root, comparison.artifacts.comparison ?? '')));
   assert.ok(await pathExists(path.join(root, comparison.artifacts.diffSvg ?? '')));
   assert.ok(await pathExists(path.join(root, comparison.artifacts.trendMarkdown ?? '')));
+  // exposed diagnostics (#137)
+  const baseDiagnosticsFile = await readJson<{ schemaVersion: string; diagnostics: unknown[] }>(path.join(root, comparison.artifacts.baseDiagnostics ?? ''));
+  const workspaceDiagnosticsFile = await readJson<{ schemaVersion: string; diagnostics: unknown[] }>(path.join(root, comparison.artifacts.workspaceDiagnostics ?? ''));
+  assert.ok(Array.isArray(baseDiagnosticsFile.diagnostics));
+  assert.ok(Array.isArray(workspaceDiagnosticsFile.diagnostics));
   const trendMarkdown = await fs.readFile(path.join(root, comparison.artifacts.trendMarkdown ?? ''), 'utf8');
   assert.match(trendMarkdown, /Code with documentation: not measured/);
   const baseManifest = await readJson<PipelineManifest>(path.join(root, comparison.artifacts.baseManifest ?? ''));