generated: '2026-06-20'
method: searched
source: https://docs.confluent.io/platform/current/kafka-rest/api.html
format: kafka-rest-error-envelope
envelope:
  fields:
    error_code: Machine-readable numeric error code (HTTP status * 100 + subcode)
    message: Human-readable description
  example: '{"error_code": 40403, "message": "Consumer instance not found."}'
notes: >-
  The Kafka REST Proxy returns errors as a JSON object with error_code and message.
  error_code encodes the HTTP status times 100 plus a subcode: 404xx map to 404 Not
  Found, 500xx to 500 Internal Server Error, etc. Generic HTTP status errors (400, 401,
  403, 404, 405, 406, 500) also apply. The Kafka Connect REST API uses a similar
  {error_code, message} envelope and returns 409 CONFLICT during connector rebalance.
error_codes:
  - code: 40401
    status: 404
    meaning: Topic not found.
  - code: 40402
    status: 404
    meaning: Partition not found.
  - code: 40403
    status: 404
    meaning: Consumer instance not found.
  - code: 40406
    status: 404
    meaning: Leader not available.
  - code: 40901
    status: 409
    meaning: Consumer cannot subscribe the specified target because it has already subscribed to a different target.
  - code: 40902
    status: 409
    meaning: Consumer cannot have multiple subscriptions of different types (topics, topic pattern).
  - code: 42201
    status: 422
    meaning: Request includes keys and/or values that are too large.
  - code: 42202
    status: 422
    meaning: Request includes an invalid offset or partition.
  - code: 42205
    status: 422
    meaning: The requested embedding format is not supported by the Content-Type / Accept headers.
  - code: 50001
    status: 500
    meaning: ZooKeeper error.
  - code: 50002
    status: 500
    meaning: Kafka error.
  - code: 50003
    status: 500
    meaning: Retriable Kafka error. Retrying may resolve the problem.
  - code: 50101
    status: 501
    meaning: No SSL support / feature not enabled on the REST Proxy.
generic_http:
  - {status: 400, meaning: Bad Request}
  - {status: 401, meaning: Unauthorized}
  - {status: 403, meaning: Forbidden}
  - {status: 404, meaning: Not Found}
  - {status: 405, meaning: Method Not Allowed}
  - {status: 406, meaning: Not Acceptable (requested embedding format unavailable)}
  - {status: 409, meaning: Conflict (e.g. Kafka Connect rebalance in progress)}
  - {status: 500, meaning: Internal Server Error}