BlogGitLab Webhooks

How to Test GitLab Webhooks

GitLab webhook events cover repository activity, merge requests, pipelines, and releases so your CI and deployment workflows stay in sync.

Looking for the broader picture? See the 7 best webhook testing tools (2026), or if you're already on Webhook.site, the 60-second migration to HookRay.

GitLab Official Webhook Docs

1. GitLab Webhook Events

GitLab can send the following webhook events to your endpoint:

push_events
tag_push_events
merge_requests_events
note_events
pipeline_events
job_events
deployment_events
release_events

2. Set Up a Test Endpoint with HookRay

Follow these steps to start receiving GitLab webhooks for testing:

  1. Go to HookRay and click "Start Testing — Free" to get your unique webhook URL.
  2. Copy the URL (e.g., https://h.hookray.com/abc123).
  3. In your GitLab dashboard, navigate to the webhook settings and paste the HookRay URL as your endpoint.
  4. Select the events you want to receive (see list above).
  5. Trigger a test event — HookRay will show the incoming webhook in real-time.

3. Sample GitLab Webhook Payload

Here's an example of what a GitLab webhook payload looks like:

payload.json
{
  "object_kind": "merge_request",
  "event_type": "merge_request",
  "user": {
    "username": "devrel"
  },
  "project": {
    "path_with_namespace": "acme/hookray"
  },
  "object_attributes": {
    "iid": 81,
    "title": "Add webhook replay endpoint",
    "state": "opened"
  }
}

4. Frequently Asked Questions

How do I test GitLab webhooks without deploying?

Use HookRay to get an instant public webhook URL. Paste it into your GitLab dashboard's webhook configuration, trigger an event, and watch the payload arrive in real time. No code, no ngrok, no deployment required. The free tier captures 100 requests per month and works on all GitLab event types.

Why aren't my GitLab webhooks arriving?

The four most common causes: (1) the endpoint URL isn't publicly accessible — GitLab can't reach localhost; (2) the wrong events are subscribed in your GitLab dashboard; (3) signature verification is rejecting the request before your handler runs; (4) GitLab can't reach your server because of a firewall, expired SSL certificate, or wrong DNS. Use HookRay's URL to isolate which of these four is failing — if HookRay receives the webhook, the problem is in your handler. If HookRay doesn't, the problem is in GitLab configuration.

Why am I getting 400 or 500 errors from my GitLab webhook?

GitLab reports the response status your endpoint returned. HookRay accepts any payload and returns 200 OK by default, so if you see 400/500 in your GitLab dashboard while pointing at HookRay, the issue is in GitLab's configuration (wrong event, malformed signing secret, etc.). If you point at your own endpoint and get 400/500, the issue is in your handler — capture the request with HookRay, replay it locally, and debug from the captured payload.

How do I verify GitLab webhook signatures?

GitLab signs each webhook request with a shared secret. Capture the raw headers and body using HookRay, then verify the signature in your application using GitLab's SDK or a standard HMAC library. Once verification works against HookRay-captured data, you can safely deploy. GitLab's docs (linked above) cover the exact signing algorithm.

Can I replay a captured GitLab webhook?

Yes — HookRay's replay feature re-sends any captured webhook to a different endpoint with one click. This is the fastest way to fix a buggy handler: capture the payload once, fix your code, and replay until it works. No need to re-trigger the event in GitLab.

5. Next Steps

  • Use HookRay's webhook replay feature to re-send captured webhooks while building your handler
  • Enable smart parsing (Pro plan) to see GitLab-specific fields highlighted automatically
  • Check the GitLab webhook documentation for the complete event reference

Ready to test GitLab webhooks?

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Free PDF: Webhook Testing Cheat Sheet 2026

One-page reference for 50+ APIs — canonical events, signing methods, sample payloads. Print it, pin it, share it.

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