On Tuesday afternoon, Twitter confirms that API has been intentionally blocked from being used by third-party Twitter apps such as Tweetbot and Twitterrific. It is impossible to use Twitter clients such as Tweetbot, Twitterrific, Birdie, Echofon, and others without access to the underlying code.

Twitter’s Dev account today said in a tweet that Twitter is “enforcing its long-standing API rules,” a change that could cause some apps not to work.

No information has been given on which API regulations the disabled Twitter apps have violated, and this is the first time Twitter has given an explanation for the lack of functionality of third-party Twitter programs since their inactivity began last Thursday.

Initially, it was thought that there was a bug causing the outage when some third-party Twitter apps became unusable last week. Twitter’s APIs were blocked for only the most popular Twitter clients, perhaps indicating an internal issue, but as Twitter refused to comment for days, however, it became clearer that it was intentional.

Not all third-party apps are offline, so there isn’t any clear motive as to why some apps went offline while others continue to work.

Since Elon Musk assumed control of Twitter, there have been major modifications to the company in the recent months. This has included substantial job losses, the re-introduction of Twitter Blue twice, and a poll which suggested that Musk should stand down from his role as CEO.