What is a webhook?

In practice

Webhooks are delivered on a best-effort basis. They arrive out of order, they arrive twice, and occasionally they do not arrive at all. A reliable receiver verifies the signature, records the event, handles repeats safely and reconciles against the source periodically to catch anything missed. Systems built as though delivery were guaranteed fail quietly and at the worst moment.

Where it fits in a build

Use webhooks for anything that should feel immediate: a payment received, a form submitted, a status changed. Keep a scheduled reconciliation alongside them for anything that matters financially or legally.

Common mistakes

• Not verifying the signature, which leaves an open endpoint anyone can post to.
• Assuming each event arrives exactly once, which creates duplicate records.
• No dead-letter queue, so a failed delivery disappears with no record.

Related terms

• API
• Idempotency
• Observability

Working on something that involves this?

ASTACKRA designs and builds AI systems, automation and custom software for businesses that need technology shaped around their own workflow. If this term turned up in a proposal and you want a straight answer about whether it applies to your situation, ask us — no obligation, and we will tell you if the answer is no.