diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..2af8ae8
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,58 @@
+name: Brain CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  lint-and-scan:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
+
+      - name: Python syntax check (hooks)
+        run: |
+          for f in user-level-files/hooks/*.py; do
+            python -m py_compile "$f"
+          done
+
+      - name: Install jq
+        run: sudo apt-get install -y jq
+
+      - name: Validate JSON files
+        run: |
+          for f in $(find . -name '*.json' -not -path './.git/*'); do
+            jq empty "$f" || { echo "Invalid JSON: $f"; exit 1; }
+          done
+
+      - name: Run script tests
+        run: |
+          bash scripts/tests/common-test.sh
+          bash scripts/tests/merge-settings-test.sh
+          bash scripts/tests/merge-mcp-test.sh
+          bash scripts/tests/setup-secrets-test.sh
+          bash scripts/tests/install-plugins-test.sh
+          bash scripts/tests/verify-test.sh
+          bash scripts/tests/install-test.sh
+          bash scripts/tests/extract-test.sh
+
+      - name: Run Python hook tests
+        run: |
+          python user-level-files/hooks/economy-mode-test.py
+          python user-level-files/hooks/economy-self-check-test.py
+          python user-level-files/hooks/economy-state-guard-test.py
+
+      - name: Gitleaks scan
+        uses: gitleaks/gitleaks-action@v2
+
+      - name: Markdownlint
+        run: |
+          npm install -g markdownlint-cli2
+          markdownlint-cli2 "**/*.md" "#node_modules"