From your conversation between Johannes N.
Can I get the app-scoped ids (for apps I own) via the original user
id. that would help too.
To get app-scoped ids from original user id can be easily done via:
https://graph.facebook.com/v2.0/?ids=http://www.facebook.com/USER_ID&access_token=ACCESS_TOKEN
Yo can use fields parameter to return only id:
https://graph.facebook.com/v2.0/?ids=http://www.facebook.com/USER_ID&fields=id&access_token=ACCESS_TOKEN
The benefit of ids instead of id because you can query multiple ids:
*www can be remove to minimize characters count.
To get app-scoped ids from username can be easily done too:
https://graph.facebook.com/v2.0/?ids=http://www.facebook.com/USERNAME&access_token=ACCESS_TOKEN
