diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
new file mode 100644
index 0000000..1b17c0c
--- /dev/null
+++ b/.github/workflows/security.yml
@@ -0,0 +1,35 @@
+name: Security and Build Checks
+
+on:
+  pull_request:
+    branches: [ "master", "dev" ]
+  push:
+    branches: [ "master", "dev" ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Type check
+        run: npm run compile -- --noEmit
+
+      - name: Audit dependencies (moderate severity+)
+        run: npm audit --audit-level=moderate