Probably not, but it depends on exactly how the code is arranged. AGPL says that anyone who can use your code (via web service) counts as having the code "conv

Probably not, but it depends on exactly how the code is arranged. AGPL says that anyone who can use your code (via web service) counts as having the code "conveyed" to them, which means the GPL terms apply. The purpose of this is to stop cases where I put GPL-derived code on a smart TV but say that since I don't let the TV owner touch the code I don't have to open source it. Or I wrap GPL-derived code as a web service and don't offer the source because the GPL'd code stays on my server. In your example, maybe Facebook takes some AGPL OAuth library and adds 20 lines of code to talk to their database. If they now give you access to call their OAuth service, they must honor a request from you to look at those 20 lines of code. If the OAuth library that you use to talk to Facebook is also AGPL and you give someone access to your service, then you have to release your source to them.