How do I get facebook username based on email address?

Title sums it up. Almost identical t开发者_Python百科o my recent twitter question at How do I get a Twitter username based on an email address?.

Just use:

https://graph.facebook.com/search?q=[EMAIL ADDRESS]&type=user&access_token=[APITOKEN]

You can actually get the API token by going to Facebook developer documentation and clicking on the friends link. The token is in the url.