问题
Noobish question: Are you supposed to respond to realtime updates (RTUs) somehow? Keep getting RTUs on the same dispute which FB has already refunded. So, should one echo something in the RTU callback? Just been through all the documentation I can find (again) and can't seem to find anything on response.
回答1:
Yes, you need to return a 200. The content type or response body do not matter. Anything else results in Facebook retrying the callback until a 200 is received, so you'll get lots of spam
来源：https://stackoverflow.com/questions/18873636/facebook-realtime-updates-dispute-response