Idempotency is something you might not see every day, but it is an important concept, especially when you are taking payments. — Heads up, we’ve moved! If you’d like to continue keeping up with the latest technical content from Square please visit us at our new home https://developer.squareup.com/blog As a developer, you are always wanting things to go smoothly, but in the world of REST APIs, that isn’t always the case. Client…