diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..52a2cf8
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,20 @@
+# Contributing
+
+Thanks for contributing to this project.
+
+## Setup
+
+1. Fork and clone this repository.
+2. Install dependencies from the project toolchain files.
+3. Run the test suite (or build) before opening a pull request.
+
+## Pull requests
+
+- Keep changes focused and clearly described.
+- Link related issues (for example `Fixes #123`).
+- Include a short test plan.
+- Match existing code style.
+
+## Conduct
+
+Be respectful and constructive in reviews and discussions.
diff --git a/README.md b/README.md
index c113493..6829ee4 100644
--- a/README.md
+++ b/README.md
@@ -90,3 +90,7 @@ src/
 tests/
   routingEngine.test.js
 ```
+
+## Contributing
+
+See [CONTRIBUTING.md](CONTRIBUTING.md).