# API Webhook Event Types and Versioned Payloads
Status: public
Confidence: medium (0.725) (verified)
Last verified: 2026-06-02
Generation: ai_structured


## TL;DR

Webhook event types and payload versions tell agents what happened, which schema to parse, and which handler should run.

## Core Explanation

Webhook delivery is not just an HTTP POST. Consumers need to know the event type, payload schema, API version, delivery ID, timestamp, signature, and retry history. Without event-type discipline, agents can misroute events or treat incompatible payloads as valid.

Versioned payloads also support safe change management. An agent can compare the received event type and schema version against the handler contract before deciding whether to process, park, or reject the event.

## Source-Mapped Facts

- GitHub documentation lists webhook events and payloads for GitHub webhooks. ([source](https://docs.github.com/en/webhooks/webhook-events-and-payloads))
- Stripe documentation lists event types that can be delivered through its Events API and webhooks. ([source](https://docs.stripe.com/api/events/types))
- Slack documentation describes the Events API as a way for apps to subscribe to events. ([source](https://api.slack.com/apis/events-api))

## Further Reading

- [GitHub Webhook Events and Payloads](https://docs.github.com/en/webhooks/webhook-events-and-payloads)
- [Stripe Event Types](https://docs.stripe.com/api/events/types)
- [Slack Events API](https://api.slack.com/apis/events-api)