> For the complete documentation index, see [llms.txt](https://docs.serverlessapigateway.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.serverlessapigateway.com/troubleshooting/wrangler-deploy-guide/local-e2e-with-unstable-dev.md).

# Local E2E with unstable\_dev

Run local worker E2E tests when you need real runtime behavior instead of only module-level assertions. The `unstable_dev` API starts a local Wrangler dev server and lets tests make real HTTP requests to the gateway. This catches issues that unit tests miss, like binding resolution and CORS header behavior.

**Last reviewed:** 2026-03-06

## When to use this

Use the deployment and troubleshooting guides when you are deploying the gateway to Cloudflare, setting up CI/CD, running tests, or diagnosing production issues. These guides cover the operational side of the gateway lifecycle from local development to production debugging.

## Key concepts

* The gateway deploys as a standard Cloudflare Worker using `wrangler deploy`. The `wrangler.toml` file defines the worker name, entrypoint, compatibility settings, and binding declarations.
* GitHub Actions can automate deployments, running config validation, tests, and docs checks before publishing the worker. The workflow uses the same `wrangler deploy` command.
* The gateway repo includes Vitest unit tests and optional E2E tests using `unstable_dev`. Run unit tests with `npm test` and E2E tests with the `RUN_LOCAL_WORKER_E2E=true` flag.
* When debugging upstream failures, isolate whether the issue is in routing (wrong path matched), auth (token rejected), or the upstream itself (backend error). Check `wrangler tail` logs for the gateway's perspective.

## Repo-grounded example

```bash
npm test
npm run test:coverage
RUN_LOCAL_WORKER_E2E=true npm run test:e2e
```

This snippet includes the `RUN_LOCAL_WORKER_E2E=true` environment variable that enables E2E tests. The test suite uses Wrangler's `unstable_dev` to start a local worker instance, then sends HTTP requests and asserts on response status, headers, and body.

## Troubleshooting

* If `wrangler deploy` fails with "missing binding", check your `wrangler.toml` for typos in binding names and verify that all referenced KV namespaces, service bindings, and secrets exist in your Cloudflare account.
* If GitHub Actions deploys succeed but the worker returns 500, check whether environment variables and secrets are set in the Cloudflare dashboard -- they are not deployed by Wrangler and must be configured separately.
* If E2E tests fail with "unstable\_dev not found", make sure you are running a Wrangler version that supports `unstable_dev` and that `RUN_LOCAL_WORKER_E2E=true` is set in your environment.
* If routes work locally but not in production, compare the config source: local dev uses the file system, while production may use KV or `SAG_API_CONFIG_JSON`. Confirm the production config matches your local config.

## Related docs

* [wrangler](/deployment/wrangler.md)
* [github actions](/deployment/github-actions.md)
* [gateway troubleshooting matrix](/troubleshooting/wrangler-deploy-guide/gateway-troubleshooting-matrix.md)


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