TIL: Testing Webhooks With curl

Webhook providers send JSON to your endpoint. You can simulate that with curl.

curl -X POST http://localhost:3000/webhook   -H 'Content-Type: application/json'   -d '{
    event: call.completed,
    call_id: ABC123,
    duration: 42
  }'

Replace the URL, the headers, and the body. Run it. See what your server returns.

I kept a file of webhook payloads for every Vonage API event. Incoming call, SMS received, delivery receipt, transcription ready. When I added a new feature I ran the relevant payload against my local server. No need to trigger the real event.

How do I test the response timing?

curl -w 'Total: %{time_total}s\n' -X POST http://localhost:3000/webhook   -H 'Content-Type: application/json'   -d '{event: ping}'

What if the webhook requires a signature?

Extract the signing secret from the provider’s dashboard and compute the signature header in your curl command, or disable signature validation during local development.