Twitter has deprecated three of its legacy developer APIs. As of today, the Site Streams, User Streams, and its REST Direct Message Endpoints are officially retired.

Shakeups are seldom welcome, and bracing itself for an angry developer backlash, Twitter has published a blog post explaining its reasioning behind the cull of its APIs. In short, it’s all about the numbers.

According to Rob Johnson, Senior Director or Product Management at Twitter, two of the legacy developer tools being retired today are only used by about one percent of third-party developers. Most developers, it seems, have migrated to the newer APIs on their own accord.

With usage of the older endpoints in the toilet, it just doesn’t make sense for Twitter to expend the effort (and money — developers aren’t cheap, especially in San Francisco) in maintaining them.

Taking the place of the older APIs are newer endpoints, which (in theory) afford developers more control and functionality. That said, they have some major limitations that guarantee to frustrate third-party developers, particulary ones that have built entire businesses around the now-deprecated APIs.

Take, for example, the Site Streams and User Streams APIs, which have been replaced with just one endpoint, the Account Activity API. Twitter is warning that as a result, some third-party applications won’t work as they used to.

“For example, instead of Tweets automatically streaming in like they once did in some third-party apps, you might need to pull to refresh like you do in Twitter-owned apps and sites,” wrote Rob Johnson in a blog post.

“Several of the most popular apps have already made updates so that you can continue using them with minimal disruption,” he added.

In the shakeup, the REST Direct Message endpoint has been replaced with two more capable endpoints, the DM POST and DM GET endpoints, which support webhooks and ‘quick replies’.

Concluding the blog post, Twitter reaffirmed its commitment to the developer community, and said it plans to continue investing in Tweetdeck — its professionally-focused Twitter client.

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