Request Replay

Request Replay

Request Replay lets you re-fire any previously captured webhook to any HTTPS endpoint — your local dev server, staging environment, or a different MockLab endpoint — with the exact same headers, body, and method as the original.

How to replay a request

  1. Open any captured request in the Webhook Inspector by clicking on it.
  2. Click the Replay button in the request detail panel.
  3. In the replay modal, review or edit the target URL (defaults to your current endpoint).
  4. Optionally modify headers or the request body before replaying.
  5. Click Send. The response from the target is shown inline.
Replay modal
Target URL
http://localhost:3000/api/webhooks/stripe
Method
POST
Headers (preserved from original)
Content-Type: application/json
Stripe-Signature: t=1714000000,v1=abc123...

Common use cases

Local development
Re-fire a real Stripe or GitHub webhook to http://localhost:3000 to debug your handler without triggering the real event again.
Test after code changes
After fixing a bug in your webhook handler, replay the same failing request to verify the fix without waiting for the next real webhook.
Cross-environment
Forward a production webhook payload to your staging server to reproduce a bug in an isolated environment.
Load testing
Replay the same request dozens of times to stress-test your handler's performance and idempotency logic.

Programmatic replay (Pro)

Pro plan users can trigger replays via the MockLab API, making it easy to integrate into CI/CD pipelines or test suites.

curl — API replay 
curl -X POST https://api.mocklab.dev/v1/requests/{requestId}/replay \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "targetUrl": "https://staging.myapp.com/webhooks/stripe"
  }'
Idempotency note
Replaying a request that has side effects (e.g. a payment webhook) will re-trigger those effects on the target server. Make sure your handler is idempotent, or use a test/staging target.
Webhook Inspector Rules Engine