We’re delighted to announce that the Beeminder API is now open to the public! Before you dive into the full documentation, let’s start with a taste of this beeliciousness. First, grab your personal auth token from beeminder.com/api/v1/auth_token.json. Let’s pretend it’s TOOLEGIT. You can now add a data point to your graph from the command line like so:
curl --data 'auth_token=TOOLEGIT×tamp=1346774400&value=1&comment=api+test' https://www.beeminder.com/api/v1/users/meta/goals/uvi/datapoints.json
Programmatic adding of data points is the biggie but the API supports most of everything else you can do from the website.  In fact, our soon-to-be-announced Android and iPhone apps use our API. (UPDATE: Android/iPhone announcement.) For that kind of fanciness, we support oauth as well as the dirt simple personal auth tokens like in the above example.
Our amazing beta users  of the Beeminder API have already done some wonderful things with it:
Some of the above use the kludgetastic alpha version of the API and haven’t been converted yet. We’ll try to get everyone to publish their hacks and mashups — perhaps to github.com/beeminder — when they upgrade to the new API.
UPDATE: More tools people are building with the Beeminder API (as Ezra Bradford points out, we should dub this the Apiary!)…
Finally, here’s a list of devices and apps we plan to integrate with  but, as you can see, there are more than we can get to in a reasonable time. (See also our previous list of tracking apps.) So don’t wait for us — start mashing things up!
UPDATE: We moved the list of upcoming integrations to the Beeminder forum.
 Please let us know if there’s something you want to automate that the API doesn’t yet support!
 Special thanks to John Millikin for finding a small security hole!
 Devices and apps we currently integrate with: TagTime, Withings, GreenGoose, Tallybee, RunKeeper, Gmail. UPDATE: Trello, Fitbit, RescueTime, Github. ANOTHER UPDATE: See the bottom of beeminder.com/services for the full list.
Image credit: Buzzbee the Robot Bee by Pete, aka buildersstudio on Etsy.