Payload

A payload is the body of an HTTP request — the data the sender wants the receiver to act on. In webhooks, the payload is almost always JSON: a structured representation of the event (event type, ID, timestamp, the affected object).

A typical webhook payload includes:

• Event type — what happened (payment_intent.succeeded)
• Event ID — unique identifier for dedup
• Timestamp — when it happened
• Data — the affected resource (the customer, the amount, the order)

Provider conventions vary in details — Stripe nests data under data.object, GitHub uses top-level fields, Slack wraps everything in an event envelope — but the structure is similar across the industry.

How production systems process payloads

Beyond parsing, production webhook systems usually need to:

• Verify signatures on raw bytes before parsing (see HMAC)
• Persist the original payload for replay (see replay and dispatch snapshot)
• Transform the payload into the shape the consumer expects
• Filter on payload contents to route events to the right destination

For the broader primer: JSON payloads explained.