Takeaways
- The request could not be completed due to a conflict with the current state of the target resource.
- This code is used in situations where the user might be able to resolve the conflict and resubmit the request.
- The server should generate a payload that includes enough information for a user to recognize the source of the conflict.
Information
Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the representation being PUT included changes to a resource that conflict with those made by an earlier (third-party) request, the origin server might use a 409 response to indicate that it can't complete the request. In this case, the response representation would likely contain information useful for merging the differences based on the revision history.