In-memory webhook relay. Accepts delivery requests over HTTP and POSTs each payload to its destination URL, retrying failures with exponential backoff.

HTTP API

POST /deliveries — body { "url": string, "payload": any }. Responds 202 with { "id" } and delivers asynchronously. 400 for invalid JSON.
GET /deliveries/:id — 200 with { "id", "url", "status", "attempts", "lastError" }, or 404. status is pending, delivered, or dead.

Delivery contract

The payload is POSTed to url with content-type: application/json.
Any 2xx response means success: status becomes delivered.
Any other outcome (non-2xx, connection error, timeout) is a failure and is retried with exponential backoff: the first retry happens after about 100ms and the delay doubles each retry. Up to 20% jitter in either direction is fine.
At most 5 attempts are made in total (the initial try plus 4 retries).
After the final failure the delivery becomes dead and lastError records a short description of the last failure.
attempts always reflects how many delivery attempts were made.

Module contract

src/app.js is CommonJS and exports createRelay(), which returns an http.Server that is not yet listening.
node src/index.js <port> starts the service.
No external dependencies; Node.js standard library only.
Run the tests with npm test.