With the most recent version (6.0) of the Facebook Graph API, there are no longer endpoints to find mutual friends between two users or get the friends list of a user.
If I want to find the number of mutual friends of two users on my app, how would I go about doing so? I can get the number of mutual friends who are also using the app (https://developers.facebook.com/docs/graph-api/reference/user/friends/), but what if I want to get the total number of mutual friends?
You can’t do that any more.
https://developers.facebook.com/docs/graph-api/changelog/version3.1#mutual-friends-api:
Mutual Friends API
These changes apply to v3.1+, and will apply to all versions on October 24, 2018.The Mutual Friends API was deprecated on April 4, 2018, and the endpoints below started returning empty data sets. The endpoints are now fully deprecated and will return an error.
/user-context/all_mutual_friends
/user-context/mutual_friends
/user-context/three_degree_mutual_friends
This has been removed for good, and there is no current replacement.
