[thexa4]

You can make it idempotent again by requiring API users to use an If-Match header with the ETag of the state they're currently expecting.

Also allows you to implement optimistic concurrency. See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If...

[fyp]

I said this in another comment and got downvoted too. Can the downvoters explain what they are downvoting for? What's wrong with if-match?