Debug GitHub webhooks

GitHub deliveries include useful headers (X-GitHub-Event, X-Hub-Signature-256, X-GitHub-Delivery). Capture them once, then replay while you iterate on your handler.

Setup

1. Create a ReplayHooks endpoint.
2. In your GitHub repo → Settings → Webhooks → Add webhook.
3. Payload URL: https://hook.replayhooks.com/x/<your-token>
4. Content type: application/json
5. Choose events (or “Send me everything”).
6. Save and click Redeliver on a recent delivery, or push a commit.

curl -X POST https://hook.replayhooks.com/x/<your-token> \
  -H 'Content-Type: application/json' \
  -H 'X-GitHub-Event: push' \
  -H 'X-GitHub-Delivery: 1234-5678' \
  -d '{"ref":"refs/heads/main","repository":{"full_name":"acme/api"}}'

{
  "ref": "refs/heads/main",
  "repository": { "full_name": "acme/app" }
}

Common failures

• Signature mismatch — compare the raw body bytes ReplayHooks captured with your HMAC input.
• Timeouts — set a custom response delay on the endpoint to practice retry handling.
• Wrong event — filter the event list by path or search the JSON tree for action.