Facebook Bot message delay

Question

I'm developing a bot on the Facebook Messenger Platform. I have noticed that, sometimes, it happens a delay between the message sending and the receiving from the server.

What is the reason?

It seems that Fb manages the messages in a queue, what are the policy of this? (time, dimension, number of messages stored.. )

Answer 1

Just make sure to return 200 status code from your server to Facebook

Facebook maintains a queue of messages received so until 200 is received for first message it will try handling your first message multiple times and this is the reason your second and so on message will get delayed to reach your server