Hey mike, have you considered adding the ability to queue responses? With this implementation if you call commitUpdate within the success callback of another commitUpdate then both of the calls must have a failure response or a success response. It's not possible for one call to fail and the next one to succeed and vice versa. I have been using this code to mock tests and it has been very helpful so far but this seems like it would be a helpful addition. Just wanted to let you know! Thanks!