diff --git a/.github/backlog/ISSUES.md b/.github/backlog/ISSUES.md
index de801a7..6a4f3f6 100644
--- a/.github/backlog/ISSUES.md
+++ b/.github/backlog/ISSUES.md
@@ -708,6 +708,8 @@ Depends on: #79, #84, and #85.
 
 Labels: `stage: 3`, `area: github`, `area: test`, `help wanted`, `need help`, `agent-friendly`, `status: ready`
 
+Status: completed by [Check-Runs Fixture Contract](../../docs/check-runs-fixture-contract.md).
+
 Acceptance criteria:
 
 - Define a sanitized fixture shape for check runs.
diff --git a/docs/check-runs-fixture-contract.md b/docs/check-runs-fixture-contract.md
new file mode 100644
index 0000000..59d651b
--- /dev/null
+++ b/docs/check-runs-fixture-contract.md
@@ -0,0 +1,240 @@
+# Check-Runs Fixture Contract
+
+This document defines the Stage 3 fixture contract for CI check-run metadata.
+
+The contract exists before a live GitHub check-runs adapter is implemented so contributors can add parser, normalizer, fake-client, and reporting tests without provider tokens or network access.
+
+Use this document with the [Provider Context Plan](provider-context-plan.md), [Provider Fixtures And Mocks](provider-fixtures-and-mocks.md), [Provider Adapter Package Boundaries](provider-adapter-boundaries.md), [GitHub Provider Permissions](github-provider-permissions.md), and [Changed-Files Fixture Contract](changed-files-fixture-contract.md).
+
+Reference GitHub documentation:
+
+- [REST API endpoints for check runs](https://docs.github.com/en/rest/checks/runs)
+
+## Goals
+
+- Define a sanitized JSON shape for check-run fixtures.
+- Cover success, failure, skipped, cancelled, timed out, and pending states.
+- Preserve enough provider-like fields to test normalizers without storing volatile provider data.
+- Define how check-run metadata enriches Maven findings without replacing report-backed evidence.
+- Keep default tests provider-token-free and network-free.
+
+## Fixture Location
+
+When implementation begins, check-run fixtures should live under:
+
+```text
+pkg/prmaven/provider/testdata/github/check-runs
+```
+
+Recommended first fixtures:
+
+```text
+success.json
+failure.json
+skipped-cancelled-timed-out.json
+pending.json
+mixed-checks.json
+```
+
+Each fixture should be small, reviewable, and safe to publish.
+
+## Sanitized Fixture Shape
+
+Check-run fixtures should use JSON.
+
+Recommended top-level shape:
+
+```json
+{
+  "provider": "github",
+  "resource": "check_runs",
+  "schemaVersion": 1,
+  "scenario": "mixed check runs for a pull request head sha",
+  "repository": {
+    "owner": "example-org",
+    "name": "example-maven-project",
+    "visibility": "public"
+  },
+  "pullRequest": {
+    "number": 123,
+    "baseRef": "main",
+    "headRef": "feature/module-change",
+    "headSha": "0000000000000000000000000000000000000000"
+  },
+  "checkRuns": [
+    {
+      "name": "Go tests",
+      "status": "completed",
+      "conclusion": "success",
+      "workflowName": "CI",
+      "startedAt": "2026-01-01T00:00:00Z",
+      "completedAt": "2026-01-01T00:02:00Z",
+      "detailsUrl": "https://example.invalid/checks/go-tests",
+      "summary": "All tests passed"
+    },
+    {
+      "name": "Maven test",
+      "status": "completed",
+      "conclusion": "failure",
+      "workflowName": "CI",
+      "startedAt": "2026-01-01T00:00:00Z",
+      "completedAt": "2026-01-01T00:03:00Z",
+      "detailsUrl": "https://example.invalid/checks/maven-test",
+      "summary": "Tests failed"
+    },
+    {
+      "name": "Optional docs",
+      "status": "completed",
+      "conclusion": "skipped",
+      "workflowName": "Docs",
+      "startedAt": null,
+      "completedAt": "2026-01-01T00:01:00Z",
+      "detailsUrl": "https://example.invalid/checks/docs",
+      "summary": "Skipped by path filter"
+    },
+    {
+      "name": "Integration",
+      "status": "completed",
+      "conclusion": "cancelled",
+      "workflowName": "CI",
+      "startedAt": "2026-01-01T00:00:00Z",
+      "completedAt": "2026-01-01T00:01:00Z",
+      "detailsUrl": "https://example.invalid/checks/integration",
+      "summary": "Cancelled by newer run"
+    },
+    {
+      "name": "Long running test",
+      "status": "completed",
+      "conclusion": "timed_out",
+      "workflowName": "CI",
+      "startedAt": "2026-01-01T00:00:00Z",
+      "completedAt": "2026-01-01T00:30:00Z",
+      "detailsUrl": "https://example.invalid/checks/long-running-test",
+      "summary": "Timed out"
+    },
+    {
+      "name": "Queued quality gate",
+      "status": "queued",
+      "conclusion": null,
+      "workflowName": "CI",
+      "startedAt": null,
+      "completedAt": null,
+      "detailsUrl": "https://example.invalid/checks/quality-gate",
+      "summary": "Waiting for runner"
+    }
+  ],
+  "expected": {
+    "total": 6,
+    "completed": 5,
+    "pending": 1,
+    "failing": ["Maven test", "Long running test"],
+    "nonBlocking": ["Optional docs", "Integration"],
+    "providerContextState": "partial"
+  }
+}
+```
+
+## Required Fields
+
+Each fixture must include:
+
+- `provider`: provider name, initially `github`;
+- `resource`: stable fixture resource name, initially `check_runs`;
+- `schemaVersion`: integer contract version;
+- `scenario`: short human-readable scenario;
+- `checkRuns`: check-run entries;
+- `expected`: normalized expectations used by tests.
+
+Each check-run entry must include:
+
+- `name`: stable display name;
+- `status`: provider status such as `queued`, `in_progress`, `completed`, `waiting`, `requested`, or `pending`;
+- `conclusion`: final result for completed checks, or `null` while pending;
+- `workflowName`: workflow or grouping label when available;
+- `startedAt`: timestamp or `null`;
+- `completedAt`: timestamp or `null`;
+- `detailsUrl`: sanitized URL or `null`;
+- `summary`: short sanitized summary or `null`.
+
+## Required Scenarios
+
+The first check-runs fixture set should cover:
+
+| Scenario | Required status/conclusion coverage | Expected behavior |
+| --- | --- | --- |
+| Passing checks | `completed` + `success` | Provider context can confirm CI health but should not create Maven findings. |
+| Failing checks | `completed` + `failure` | Provider context can point to failing CI, but Maven findings still require local report evidence. |
+| Skipped checks | `completed` + `skipped` | Skipped checks should be reported as non-blocking context unless a future issue defines stricter behavior. |
+| Cancelled checks | `completed` + `cancelled` | Cancelled checks should be diagnostic context, not Maven evidence. |
+| Timed-out checks | `completed` + `timed_out` | Timed-out checks can explain incomplete CI, but should not invent test failures. |
+| Pending checks | `queued`, `in_progress`, or `pending` with `conclusion: null` | Pending checks should mark provider context as partial. |
+
+## Sanitization Rules
+
+Fixtures must not include:
+
+- real private repository names;
+- real branch names from private repositories;
+- real commit SHAs, check-run IDs, node IDs, or database IDs;
+- real actor names, emails, tokens, or account IDs;
+- signed URLs;
+- artifact URLs;
+- volatile API URLs;
+- raw log output containing private code or secrets.
+
+Use stable placeholder values such as `example-org`, `example-maven-project`, `feature/module-change`, and zeroed SHAs.
+
+## Maven Evidence Boundary
+
+Check-run metadata enriches context. It does not replace Maven report evidence.
+
+Provider-aware output may use check-run metadata to say:
+
+- which CI checks are failing, pending, skipped, cancelled, or timed out;
+- whether provider context is complete or partial;
+- which check name or workflow likely corresponds to Maven validation;
+- where a user might inspect CI details.
+
+Provider-aware output must not:
+
+- create a Maven finding from a failing check alone;
+- change the source report path of a local Maven finding;
+- hide local Maven findings when check-run context is missing;
+- change report-only exit behavior unless a future issue explicitly scopes that behavior.
+
+## Fake Client Expectations
+
+Fake clients for check runs should support:
+
+- successful response with completed checks;
+- successful response with pending checks;
+- empty check-run response;
+- paginated response behavior without live network calls;
+- missing token;
+- insufficient permissions;
+- rate limit;
+- not found;
+- unsupported status or conclusion.
+
+Error behavior should follow [Provider Errors And Offline Fallbacks](provider-errors-and-fallbacks.md).
+
+## Test Expectations
+
+Default tests should:
+
+- load committed check-run fixtures from disk;
+- validate required fixture fields;
+- normalize statuses and conclusions;
+- assert expected provider context state;
+- assert that failed check runs do not create Maven findings by themselves;
+- run without GitHub credentials;
+- run without network access;
+- avoid depending on real GitHub API responses.
+
+Optional live-provider tests may exist later, but they must be skipped by default and must not be required by `go test ./...`.
+
+## Compatibility With Future JSON Output
+
+Check-run context should be additive.
+
+Future JSON fields should preserve existing local report fields and add provider context under a separate provider-aware extension. Missing, partial, pending, cancelled, or timed-out check-run data should be represented as provider diagnostics or metadata rather than Maven findings.
diff --git a/docs/provider-context-plan.md b/docs/provider-context-plan.md
index 63317c3..01fc0a1 100644
--- a/docs/provider-context-plan.md
+++ b/docs/provider-context-plan.md
@@ -72,3 +72,4 @@ Fixture and fake-client guidance lives in [Provider Fixtures And Mocks](provider
 Provider failure behavior lives in [Provider Errors And Offline Fallbacks](provider-errors-and-fallbacks.md).
 GitHub read-token expectations live in [GitHub Provider Permissions](github-provider-permissions.md).
 Changed-file fixture expectations live in [Changed-Files Fixture Contract](changed-files-fixture-contract.md).
+Check-run fixture expectations live in [Check-Runs Fixture Contract](check-runs-fixture-contract.md).
diff --git a/docs/provider-fixtures-and-mocks.md b/docs/provider-fixtures-and-mocks.md
index 473799a..add5fca 100644
--- a/docs/provider-fixtures-and-mocks.md
+++ b/docs/provider-fixtures-and-mocks.md
@@ -4,7 +4,7 @@ Stage 3 provider behavior must be testable without live GitHub, GitLab, CI provi
 
 This document defines the fixture and fake-client contract for optional provider context.
 
-Changed-files fixtures have a dedicated contract in [Changed-Files Fixture Contract](changed-files-fixture-contract.md).
+Changed-files fixtures have a dedicated contract in [Changed-Files Fixture Contract](changed-files-fixture-contract.md). Check-run fixtures have a dedicated contract in [Check-Runs Fixture Contract](check-runs-fixture-contract.md).
 
 ## Fixture Principles