Elon Musk’s Twitter has quietly updated its agreement with developers, which now states that they cannot create their own clients to use the social network.

The Restrictions section of the Twitter Developer Agreement has been updated to prohibit “use or access the Licensed Materials to create or attempt to create a substitute or similar service or product to the Twitter Applications.” The addition is the only major change in the 5,000-word deal, but it essentially undoes decades of work by developers of popular third-party clients for Twitter.

Problems accessing the Twitter API started last week, and the company did not provide the developers with any meaningful explanation. Which was to be expected, since Twitter no longer has a communications team, and most of the staff working on the developer platform were also cut in mass layoffs last year.

Twitter’s third-party clients have always been an integral part of Twitter. Twitterrific, one of the more prominent apps affected by last week’s API outage, was created before Twitter even had its own iOS app, and is credited with inventing the word “tweet” as well as other features that are now commonly associated with Twitter.

In recent years, clients like Tweetbot and Fenix have had a loyal following thanks to their lack of ads and other features that many regular users of the social network dislike. For a while, Twitter management tried to impose more restrictions on third-party client developers, but in 2021 it changed its policy, removing a section that discouraged, but did not prohibit, app developers from “copying” the service’s core capabilities. The change was part of Twitter’s broader strategy to improve relations with developers, including third-party creators.

However, with the purchase of the company by Elon Musk, the previous policies of Twitter went down in history. So with no access to the API, developers began to remove their apps for the social network.

Sean Heber of Twitterrific confirmed on his blog that a 16-year-old client has ceased to exist. “We are sorry to say that the app’s sudden and undignified demise is due to an unannounced and undocumented policy change by an increasingly capricious Twitter – a Twitter that we no longer recognize as trustworthy nor want to work with any longer,” Heber wrote in an updated message.

Well, such steps will definitely not increase the popularity of Twitter, because many users spent their time using the social network only thanks to third-party applications, which often had a more convenient and understandable interface.