API & Webhook Live Tester
Lightweight developer suite: send HTTP requests with custom headers and capture incoming real-time webhook payloads with temporary endpoints.
How Does the API & Webhook Tester Work?
Anti-CORS Secure Proxy
Browsers block direct JavaScript cross-origin requests. Arostik routes outgoing calls through an edge proxy resolving latency and status codes.
Live In-Memory Webhooks
Creates temporary isolated in-memory channels capturing push events from payment gateways or web services without ngrok or local servers.
Complete Header Inspection
Inspect critical authentication tokens, HMAC signatures (Stripe-Signature, X-Hub-Signature), and raw Content-Type payloads.
Common API & Webhook Errors and Step-by-Step Fixes
Issue 1: 401 Unauthorized or 403 Forbidden HTTP Status
Add an 'Authorization' header in Headers tab using 'Bearer YOUR_API_KEY' or 'Basic HASH', verifying token expiry.
A 403 status indicates a valid token lacking requisite read/write scopes for the target resource.
Issue 2: Webhook event does not appear in incoming list
Verify your copied URL includes the '?channel=...' query string parameter and listening indicator is green.
Run the sample cURL command from your terminal to verify network firewall egress permission.
Did You Know? History of APIs & Webhooks
The term 'Webhook' was coined in 2007
Jeff Lindsay coined the term in 2007 describing user-defined HTTP callbacks, eliminating expensive server polling loops.
HTTP Status 418: 'I'm a teapot' (RFC 2324)
Created in 1998 under RFC 2324 as an April Fools protocol for coffee pots (HTCPCP). Modern web frameworks still preserve it as an easter egg.
The technical difference between PUT and PATCH
PUT idempotently replaces the whole resource entity; PATCH applies partial modifications to specific fields without overwriting the record.
Stripe dispatches over 1 billion webhooks monthly
Global e-commerce runs on webhooks: payment confirmations trigger sub-second HMAC-signed push webhooks informing merchant backend servers.