Twitter is announcing a change to its API that will give third-party developers more access to the rankings that the company assigns to tweets, letting them find the higher-value tweets in a stream. According to Twitter, the addition will let apps more easily surface certain types of content from noisy or high-volume feeds, showing users only the most noteworthy and engaging material.

As far as what goes into determining a tweet's value, Twitter's Top Tweet algorithm finds the ones with the most engagement from other users, in terms of retweets, replies, "and more." What Twitter is announcing is a new piece of tweet metadata called "filter_level" that's given a value of "none," "low," or "medium." The latter correlates roughly to the aforementioned "Top Tweets," meaning that it will now be possible for third-party developers to approximate the search results on Twitter's web client within their own apps, for instance.

the first time Twitter is making its own value judgments on tweet quality so explicitly public

So if Twitter is trying to concentrate control over its platform, why make something like its tweet rankings available to third-party developers? It’s possible that the company is extending an olive branch after the backlash it received from sweeping API changes in August, but the real audience for the API changes might be the developers of social analytics and social influence ranking products like Topsy and Klout rather than traditional Twitter clients like Tweetbot. The move is particularly significant for being the first time Twitter is making its own value judgments on tweet quality so explicitly public; information that would be valuable to developers looking to sift through the service's staggering volume of content.

The company also says that it has reserved an even higher value for "filter_level" for use sometime in the future. But the company isn't saying exactly what the "high" value will denote — and so the purpose of both it and this newfound openness with developers is a little unclear. One answer might be that Twitter plans to start charging for access to certain parts of the API down the road. It certainly hasn't made any announcements to that effect, but it wouldn't be the first. Whatever Twitter's future plans are, the new "filter_level" metadata will be free to use when it launches next week, on February 20th.