https://techcrunch.com/2023/01/19/twitter-officially-bans-third-party-clients-after-cutting-off-prominent-devs/

After cutting off prominent app makers like Tweetbot and Twitterific, Twitter today quietly updated its developer terms to ban third-party clients altogether.

Spotted by Engadget, the “restrictions” section of Twitter’s 5,000-some-word developer agreement was updated with a clause prohibiting “use or access the Licensed Materials to create or attempt to create a substitute or similar service or product to the Twitter Applications.” Earlier this week, Twitter said that it was “enforcing long-standing API rules” in disallowing clients access to its platform but didn’t cite which specific rules developers were violating. Now we know — retroactively.