I've got an email from Facebook telling me that I have been making API calls to Graph API v2.0 and I need to migrate those calls to v2.1.
Is there option to know the source (which website) of these calls so I'll know where to change them? Any log somewhere?
You have to read this documentation of Facebook. You'll find all info about Website, iOs and Android Upgrade on https://developers.facebook.com/docs/apps/upgrading. There is so much changes since v2.0. The actual version is 2.5. But if you only want Upgrading from v2.0 to v2.1 here is the section of documentation from Facebook you have to read.
Upgrading from v2.0 to v2.1 Graph API
FQL is no longer available
FQL has been removed in v2.1, and can no longer by queried either directly, or via the Graph API.
App Insights endpoint has been moved and functionality changed
v2.1 includes access to the new App Insights data via a new /app_insights edge. This replaces the previous /insights edge on the App node. Apps using this edge should migrate to the new edge, and check the updated list of metrics and parameters.
New Field Expansion format for Making Nested Requests
A new, more compact syntax has been introduced for making nested API requests. The old syntax is still available in v2.1, but apps should switch to using the new format as soon as possible.
Queries to graph.facebook.com/?id={url} replaced by new URL node
There was previously a Graph API endpoint graph.facebook.com/?id={url} available that allowed apps to retrieve Open Graph objects, App Links, or share metrics that were associated with a particular URL. In v2.1, these must instead be retrieved via the new URL node.
API Response Changes
All API endpoints will now always return valid JSON. Many API calls before v2.1 returned plain text true or a raw int like 378293782 as the response. With v2.1, those calls will now return valid JSON, such as:
{
"success": true
}
This will affect any API endpoints that previously returned something that was not valid JSON - typically this is mostly only publishing or deleting endpoints.
Consult the reference docs for Graph API to see if any endpoints that you use have changed response formats. installed permission no longer exists
The /me/permissions edge previously returned an installed pseudo-permission that would indicate that someone had installed an app. In v2.1 this permission has been removed, and instead apps should assume that when /me/permissions returns any data (and not an error) that the user has installed the app.
uri no longer a valid field on profile pictures
Apps previously requesting uri should instead use url./v2.1/{post-id} will now return all photos attached to the post
In previous versions of the API, only the first photo was available via the picture field of a post. Now, apps will be able to request all the photos attached to a post via the attachments field.
REST API
The previously deprecated REST API has been completely removed in v2.1, and all apps still using it must migrate to using Graph API.
If your mobile app is using the undocumented auth.ExtendSSOAccessToken endpoint from the REST API to extend long-lived access tokens, you need to upgrade your app to use the full iOS or Android SDK. The SDKs will automatically handle extending access tokens.