I find it interesting that you hold the MailChimp API in such a high regard. I use it frequently as an example of how not to build an API. I find it hard to in

I find it interesting that you hold the MailChimp API in such a high regard. I use it frequently as an example of how not to build an API. I find it hard to integrate efficiently with it - it got worse from version 2 to 3, although some of the blunders have later been fixed. You're probably right that the error messages are relatively thorough. Many of the constraints aren't documented in the reference documentation, though, so it requires trial-and-error.