Is REST DELETE really idempotent?

http rest http-headers
Ben Noland picture Ben Noland · Nov 3, 2010 · Viewed 32k times · Source

DELETE is supposed to be idempotent.

If I DELETE http://example.com/account/123 it's going to delete the account.

If I do it again would I expect a 404, since the account no longer exists? What if I attempt to DELETE an account that has never existed?

Answer

Chris McCauley picture Chris McCauley · Nov 3, 2010

Idempotence refers to the state of the system after the request has completed


In all cases (apart from the error issues - see below), the account no longer exists.

From here

"Methods can also have the property of "idempotence" in that (aside from error or expiration issues) the side-effects of N > 0 identical requests is the same as for a single request. The methods GET, HEAD, PUT and DELETE share this property. Also, the methods OPTIONS and TRACE SHOULD NOT have side effects, and so are inherently idempotent. "


The key bit there is the side-effects of N > 0 identical requests is the same as for a single request.

You would be correct to expect that the status code would be different but this does not affect the core concept of idempotency - you can send the request more than once without additional changes to the state of the server.

Related questions

Customize the Authorization HTTP header

I need to authenticate a client when he sends a request to an API. The client has an API-token and I was thinking about using the standard Authorization header to send the token to the server. Normally this header is …

Read More
Paging in a Rest Collection

I'm interested in exposing a direct REST interface to collections of JSON documents (think CouchDB or Persevere). The problem I'm running into is how to handle the GET operation on the collection root if the collection is large. As an …

Read More
REST: HTTP headers or request parameters

I've been putting in some research around REST. I noticed that the Amazon S3 API uses mainly http headers for their REST interface. This was a surprise to me, since I assumed that the interface would work mainly off request …

Read More