Tapbots has announced that it is closing the public alpha of Tweetbot for Mac, the Mac OS X port of its popular iOS Twitter client. In a blog post, the company said that Twitter's new limits on how many users could be authorized on an application at one time made a public alpha or beta unworkable. Although Tapbots will still be releasing Tweetbot for Mac when it's finished, it says it's been working with Twitter but hasn't been able to come to an agreement on raising or changing the cap for the alpha.

As Twitter announced in mid-August, developers who make new third-party clients for Twitter are limited to 100,000 API tokens per app, capping the total user base unless the company works with Twitter directly or gets permission for more users. A token is used whenever someone grants the app access to their Twitter account, and it's returned when they manually revoke access. When the final software is released, most of those tokens can at least be tied to a payment, but Tapbots says that during an alpha, someone "might use the app, decide they don’t like it, and the token would be gone forever." Fans of Tweetbot will still be able to purchase the Mac version "in the near future."