The routes document End Close is managing for the environment this API key belongs to: which processor webhook routes the relay accepts, how each is verified, and the field map that decides what leaves your network.

This is the only thing End Close tells a relay, and the status code is the whole message. A 200 is itself the statement that End Close owns this configuration, so the relay runs the document and hides its own config editor — there is no local copy that can drift. A 304 says the same and that nothing moved. A 404 means End Close is not managing this environment (nothing provisioned, or the switch turned off in Settings → Relay). It is a state, not a terminal answer: keep the document you already have, fall back to local configuration if you have one, and keep polling at your normal cadence — this is the only way you will hear that management was switched back on, and stopping forwarding on a 404 would turn a settings toggle into an outage.

Poll it with If-None-Match. The 200 carries a strong ETag identifying the document, which changes only when the document itself changes — a save that alters nothing keeps it — so the ordinary answer on a heartbeat is a 304 with no body. The API key alone resolves the environment: no parameters are needed, and rotating the key does not change the document. routes has the same content as the routes: block of the relay's relay.yaml; environment is informational.

{
  "environment": "Sandbox",
  "routes": [
    {
      "id": "payabli-settlements",
      "auth": {
        "secret_env": "PAYABLI_WEBHOOK_SECRET"
      }
    }
  ]
}