diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..7dc54f8
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,27 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  lint:
+    name: Lint & Syntax Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+
+      - name: Install ruff
+        run: pip install ruff
+
+      - name: Check syntax errors (E999) and undefined names (F821)
+        run: ruff check --select=E999,F821 .
+
+      - name: Compile all .py files (catch SyntaxError)
+        run: python -m compileall -q .