All HTTP status codes

HTTP 422 Unprocessable Content

Client Error

The request is syntactically valid but semantically wrong — well-formed JSON that fails business validation (missing fields, invalid values).

Defined in RFC 9110

Common causes

  • Validation failures: required fields missing, values out of range
  • Referencing related entities that don't exist

How to fix it

  1. Read the response body — APIs typically list per-field errors

  2. Validate on the client against the same rules before submitting

Related status codes

400 Bad Request

The server can't or won't process the request because the client sent something malformed — invalid JSON, bad query parameters, broken headers or framing.

409 Conflict

The request conflicts with the resource's current state — classic cases are duplicate creation and stale optimistic-locking versions.

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