diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..b9b38b7
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,34 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    name: Test on Node ${{ matrix.node }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node: [18, 20, 22]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Node ${{ matrix.node }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+
+      # No dependencies to install — the engine is zero-dep. Run the smoke test,
+      # which validates every example, asserts self-contained output, and
+      # negative-tests the schema validator.
+      - name: Run tests
+        run: npm test
+
+      # Sanity-check the CLI entry point resolves and prints help.
+      - name: Smoke-check the CLI
+        run: node bin/cli.mjs --help
diff --git a/README.md b/README.md
index fdef34c..63ae74c 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Think-In-HTML
 
+[![CI](https://github.com/vibhusharma101/Think-In-HTML/actions/workflows/ci.yml/badge.svg)](https://github.com/vibhusharma101/Think-In-HTML/actions/workflows/ci.yml)
+
 Turn code, an AI thinking transcript, or any text into an explorable, interactive lesson — in one command.
 
 Think-In-HTML takes a file, a code flow, a reasoning transcript, or a block of prose and generates a **single self-contained `.html` file** that explains it like a teacher would. Open it in any browser, share it with anyone — no server, no install, no dependencies.