412.md

set	4
code	412
layout	code
title	Precondition Failed
references	Rails HTTP Status Symbol Go HTTP Status Constant Symfony HTTP Status Constant Python2 HTTP Status Constant Python3+ HTTP Status Constant Python3.5+ HTTP Status Constant :precondition_failed http.StatusPreconditionFailed Response::HTTP_PRECONDITION_FAILED httplib.PRECONDITION_FAILED http.client.PRECONDITION_FAILED http.HTTPStatus.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.

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• Source: RFC7232 Section 4.2