diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..d97954d
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,57 @@
+# CodeRadar CI — the Gate 0 pipeline.
+#
+# Every PR must pass: build (strict TS), typecheck, unit tests, and the eval
+# gate (eval/thresholds.json). The scorecard is uploaded as an artifact on
+# every run, pass or fail, so regressions are inspectable.
+#
+# Threshold ratchet rule (docs/testing-strategy.md): eval/thresholds.json
+# values may be RAISED in any PR; LOWERING one requires a written
+# justification in the PR body. Thresholds never loosen silently.
+
+name: CI
+
+on:
+  push:
+    branches: [main, development]
+  pull_request:
+
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4 # reads the packageManager field
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install
+        run: pnpm install --frozen-lockfile
+
+      - name: Build (strict TS)
+        run: pnpm build
+
+      - name: Typecheck
+        run: pnpm typecheck
+
+      - name: Unit tests
+        run: pnpm test
+
+      - name: Eval gate
+        run: node eval/dist/run.js
+
+      - name: Upload scorecard
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: eval-scorecard
+          path: eval/scorecard.json
+          if-no-files-found: ignore
diff --git a/TRACKER.md b/TRACKER.md
index 74f1c6c..3149476 100644
--- a/TRACKER.md
+++ b/TRACKER.md
@@ -5,8 +5,8 @@
 ## Status
 
 - **Current phase:** 0 — Foundations
-- **Next step:** 0.4 — CI pipeline
-- **Done:** 0.1, 0.2, 0.3
+- **Next step:** 1.1 — Endpoint resolution (constants, templates, patterns)
+- **Done:** 0.1, 0.2, 0.3, 0.4
 - **Gates passed:** none yet (Gate 0 completes with 0.4)
 
 ## What CodeRadar is
@@ -76,7 +76,7 @@ The v0.1 schema is definition-only, which is *wrong* for C1 — fix before build
 - CLI: `scan` records commit SHA (via `git rev-parse`, `dirty` from `git status`).
 **Accept:** round-trip test (scan → save → load → deep-equal); schema drift test; `coderadar scan` output includes SHA.
 
-### [ ] 0.4 CI pipeline
+### [x] 0.4 CI pipeline
 **Failure modes:** D1, process
 **Build:** GitHub Actions workflow: install (pnpm cache) → build → typecheck → vitest unit tests → `pnpm eval` → upload scorecard as artifact. Threshold ratchet rule documented in the workflow file header (raising OK; lowering needs PR-body justification).
 **Accept:** CI green on a PR; a deliberately broken fixture in a test branch turns it red. **Gate 0 passes.**