4×× Client Error
412 Precondition Failed
One or more conditions given in the request header fields evaluated to false when tested on the server.
This response code allows the client to place preconditions on the current resource state (its current representations and metadata) and, thus, prevent the request method from being applied if the target resource is in an unexpected state.
- Source: RFC7232 Section 4.2
412 Code References
    Rails HTTP Status Symbol :precondition_failed
  
    Rust HTTP Status Constant http::StatusCode::PRECONDITION_FAILED
  
    Go HTTP Status Constant http.StatusPreconditionFailed
  
    Symfony HTTP Status Constant Response::HTTP_PRECONDITION_FAILED
  
    Python2 HTTP Status Constant httplib.PRECONDITION_FAILED
  
    Python3+ HTTP Status Constant http.client.PRECONDITION_FAILED
  
    Python3.5+ HTTP Status Constant http.HTTPStatus.PRECONDITION_FAILED
  
    .NET HTTP Status Constant System.Net.HttpStatusCode.PreconditionFailed