Webhook
What is Webhook?
A webhook is an HTTP callback a platform sends to a URL your application owns whenever something happens — a message is delivered, a call ends, a reply arrives. Instead of polling an API for changes, your server exposes an HTTPS endpoint and the platform POSTs the event to it as it occurs, usually with a signed payload your code verifies before acting on it. Webhooks are the standard way CPaaS platforms push delivery receipts, inbound messages, and call progress events to your application.
More detail
A webhook is a push, not a pull: the platform holds the event loop, and your application only has to be reachable over HTTPS. Each delivery is a signed HTTP POST your endpoint acknowledges quickly — a slow or failing endpoint can delay or drop events depending on the platform's retry policy, so the receiving side usually acknowledges first and processes asynchronously.
Orbit delivers messaging and voice events — delivery receipts (DLRs), inbound MO messages, WhatsApp delivery and read statuses, and call lifecycle events — as signed webhooks to endpoints you configure per channel, each with its own delivery timeout, so event handling stays near real time without polling message or call records.
Frequently asked
- How is a webhook different from polling an API?
- Polling is pull: your application asks the API 'has anything changed?' on a timer, which adds delay and wasted requests. A webhook is push: the platform tells your endpoint the moment an event occurs, so delivery receipts and inbound messages reach you in near real time with no polling loop to maintain.
- How do I make sure a webhook really came from the platform?
- Treat every webhook as untrusted until verified: reputable CPaaS platforms sign each delivery (for example an HMAC signature over the payload), and your endpoint should recompute and compare that signature before processing — and reject anything unsigned or mismatched. Never act on a payload you haven't verified.
- What happens if my webhook endpoint is down or slow?
- Platforms typically retry failed deliveries on a backoff schedule for a bounded window, and most let you inspect or replay missed events after the fact. Acknowledge deliveries quickly and process them asynchronously, because a slow endpoint can stall retries and drop events past the platform's retry window.
See also
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