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+# AGENTS.md
+
+## Project overview
+
+- This repository is a small ESM Node.js package that exports a single middleware from `lib/index.js`.
+- Runtime support starts at Node.js 18 (`package.json`), and CI tests the package on Node.js 18, 20, and 22.
+- Linting runs with Biome, and releases are managed through `release-please`.
+
+## Working agreements
+
+- Use `npm` for dependency and script commands.
+- Prefer small, focused changes. Avoid unrelated cleanup in the same PR.
+- Use Conventional Commits for commit messages and PR titles (for example: `fix: ...`, `feat: ...`, `docs: ...`). This repository uses `release-please`, so incorrect commit or PR prefixes can break release automation.
+- Keep the public middleware API and the README example aligned when behavior or options change.
+- Do not edit `CHANGELOG.md` or `.release-please-manifest.json` manually unless the task is explicitly about the release process.
+
+## Commands
+
+- Install dependencies: `npm install`
+- Run tests: `npm test`
+- Run lint: `npm run lint`
+- Auto-fix formatting and lint issues: `npm run fix`
+- Generate coverage report: `npm run coverage`
+
+## Testing notes
+
+- `npm test` runs with `NODE_ENV=production`, which is important because the middleware bypasses redirects outside production mode.
+- HTTPS behavior is covered in `test/test.js` using the certificates under `test/certs/`.
+- If you change request handling or HSTS behavior, update or extend tests in `test/test.js`.
+
+## Files to check during changes
+
+- `lib/index.js`: package implementation and exported middleware.
+- `test/test.js`: behavioral coverage for redirects, HSTS headers, and ignored routes.
+- `README.md`: user-facing API and usage examples.
+- `example/app.js`: example app for manual testing and docs alignment.