This is going to be a pretty long answer, the short summary of which is that HTTP 409 is the most appropriate status code to report the failure of an "add new resource" operation, in case a resource with the same identifier already exists. What follows is the explanation why, based solely on what's stated in the authoritative source - RFC 7231.
A 409 Conflict response is definitely wrong if the client can't resolve the conflict and delete the request later. That is, unless the resource has state tracking whether it can be deleted or not, 409 Conflict is not a good fit.
In case the conflict had something to do with the file already existing, I added code to physically delete the file before uploading it, and i'm still getting some 409's.
Reasons for a 409/Conflict HTTP error when uploading a file to ...
It's obvious that a successful validation will return a 200 OK. But I don't feel that a success status code is appropriate for a validation failure. I'm leaning towards a 409 Conflict, but I've only ever used this to reject a PUT or POST. Is it valid (snicker) to have a validation failure indicated by a 409, or is there a better way?
The [$-409] is a locale code, given in hexadecimal. Prefixing a date with a certain locale code determines what is shown when you use the various date time format codes.
409 is a fine choice for your case - in particular, it calls attention to the body of the request, informs that there is some incompatibility between the semantics of the current request and the current state of the resource, and indicates that the client may be able to resolve the conflict and resubmit the request.
Is it OK to use a 409 HTTP code in the case when the record with ...
Edit conflicts and 409 vs. 412 responses Asked 12 years, 10 months ago Modified 7 years, 1 month ago Viewed 7k times
If the user is already registered by that email, I'll return a 409 CONFLICT status. However, I'm not quite sure what the proper content is required to return with that -- for example, do I return that user object?
rest - What to return with a 409 conflict? - Stack Overflow
Even after reading many documents, books, spec I couldn't 100% be certain whether I should use http status code 403 or 409 in my case. Some argue that 403 should be used only with an authorization...
The height for one of my rows in excel maxes out at 409.5 and I need to increase the height. Where/how can I fix this.
formatting - My Excel row is locked at height of 409.5 and I want to ...
HTTP 409 Conflict on POST request Asked 2 years, 11 months ago Modified 2 years, 11 months ago Viewed 3k times
Azure Function works but reports "409 The specified container already exists" Asked 4 years, 2 months ago Modified 3 years, 7 months ago Viewed 11k times