Retrieving Facebook Live comments in real-time from Webhook?

Question

I'm trying to write a program that can retrieve the comments (as they happen) in my Facebook Live videos. Looking through the Docs I see the following text:

Reading Comments and Reactions

You can read live video comments by polling the Video Comment edge. In order to do this in the most efficient way so as not to exceed Graph API rate limits, we recommend receiving API updates via webhooks. You can also read live video reactions by polling the Reactions edge.

When I look at webhooks I can't seem to find any documentation that states how often they are called. Are they called on every comment, or at some pre-defined interval?

Also, webhooks callbacks run the risk of being received out of order. What's the best way to ensure that no messages are missed?

Thanks.

Answer 1

As of 3/7/2017 it is possible to be alerted about a comment posting via webhook but the comment itself are not sent in the request.