Less than a full day after launching its new location-sharing feature, Facebook has opened up Places to developers.

Thursday afternoon, developers gained access to users’ check-in data via Facebook’s Graph API. Developers can also access check-in data from locations, like restaurants and businesses, to see who’s checked in there.

As we mentioned in our coverage of Wednesday evening’s launch, the Places data is read only for now. Applications can’t write or search Places data through the API. Those features are only available to Facebook’s launch partners for Places — Gowalla, Foursquare, Yelp and Booyah — while the kinks get ironed out. Everyone will get access to write and search Places data within a few months, according to Facebook.

The documentation for the Graph API has been updated to provide instructions for calling Places.

So sayeth the man page: “Every check-in is associated with a check-in ID that represents an object in the graph. Check-ins are associated with locations represented by Facebook Pages; the location must have a Facebook Page ID, whether the Page was created on Facebook directly or using the Open Graph protocol.”

If you don’t want to join in any of Facebook’s check-in reindeer games, the How-To Wiki has instructions on disabling Places in your account.

See Also:

• Places Turns Facebook Into a Location Sharing Powerhouse
• Facebook Shows Off New Tools to Socialize the Entire Web
• Flickr Hooks Up With Facebook for Photo-Sharing Love