Facebook launched a Groups API last week to allow developers to build applications which can control Facebook’s new Groups feature programmatically. The API currently enables developers to pull a Group’s basic info including name, description, owner, last updated time, and privacy setting; access the Group’s picture, view existing posts; see all members; and post to the Group. Facebook says developers will also be able to create Groups and manage Group membership via the API “in the near future.”

The API will allow developers to build applications over the feature, such as Group feed readers, Group recommendation engines, and more. Developers using the API to control old groups won’t have to modify their code.

Facebook’s Graph API reference page for Groups details exactly what is available through the API. Note that some information about the old groups product such as property names for links and venues, which don’t exist for new Groups, is listed here. The API can be used to publish to to the feed of a Group using POST if the publish_stream permission has been attained.

No authentication is necessary to access the data of open Groups, except “{group}/members” which requires authentication from any user, but not necessarily a member of the Group. Non-members can authentications can be used to access the basic information and picture of a closed Group, but not its feed. Despite the closed privacy setting supposedly allowing non-members to see members, calling for this data returns a granted request but no data on who is part of the Group.

Authentication must come from a Group member to get any data about a secret Group other than that a Group does exist for that ID. One option for those wishing to explore the Groups API is the Apigee Facebook API Test Console.

We’ve yet to see any developers release products with Groups API integration, but there is potential. Since Groups exist as secondary content channels to the default news feed shown on the Facebook home page, a way to aggregate the posts from all of a user’s Groups into a single, easy-to-browse feed could be a useful application. Group recommendation engines which helps users to find open Groups which appeal to them could also be an area for innovation with the API.

Since the product has yet to be fully rolled out, and Facebook has promised that additional API functionality is on the way, developers may be hesitant to devote resources to the Groups API so early. However, there is much to be gained by the first developer to help users better find, use, and manage the Facebook microcosms created through Groups.