Error responses

Read send retry behavior before you retry an uncertain operation.

Error responses

Every error uses one JSON shape:

{
  "code": "invalid_destination",
  "message": "The destination is invalid.",
  "request_id": "f066b48a-7a7b-4073-9cdd-eb65b49bad9a",
  "field_details": [
    { "field": "to", "message": "The recipient handle is invalid." }
  ]
}

The API uses 400 for malformed input and cursor mismatches, 401 for authentication, 403 for the allowlist, 404 for unknown resources, 409 for an idempotency conflict, 413 for large media or a JSON body over 1 MiB, 422 for validation, 501 for unsupported operations, 502 for an uncertain send, reaction, read, or typing action, and 503 for unavailable Messages access, database, sender, or request store. A conflicting idempotency key or protected typing draft returns 409. An ambiguous exact-participant conversation lookup also returns 409.