webhook.payload_invalid

Body is not JSON at all (after successful verification), or a Marketplace notification lacks the operation id or the action, so it has no deduplication key (7). Notifications that parse and carry both but cannot be applied (action mismatch, unknown action) are **not** errors: they are stored, verified and reconciled, and answered 200.

Code	`webhook.payload_invalid`
HTTP status	400
Category	`Validation`
Arguments	None (args is {})

Example response

application/problem+json

{
  "type": "https://docs.test.konsolutelab.uk/errors/webhook.payload_invalid",
  "title": "…",
  "status": 400,
  "code": "webhook.payload_invalid",
  "args": {},
  "traceId": "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01",
  "instance": "/api/v1/…"
}

Handling it

Branch on code, not on title or the status alone, and log traceId. Codes are stable; new codes may appear, so fall back on the HTTP status for a code you do not know. See Handling errors and the list of codes.