Changes are coming soon for how third-party applications can use Twitter’s application programming interface (API), the software tool an app uses for accessing Twitter content.

Despite a warning in June that changes were coming, the switch is drastic enough to raise debate from software developers and critics. Instapaper developer Marco Arment said the changes will make him think twice before adding any Twitter-based features to his software. Others argue that at least Twitter is giving clear guidance to developers about how to use Twitter.
But are Twitter’s changes anything for users to worry about? If you’re happily using Twitter through the service’s own client apps to check your tweet stream and send out tweets, then no. But if you are using a third-party application to access Twitter, here’s some good news and, possibly, some bad news for the future.
Better Refresh
If you access Twitter through a third-party application such as Hootsuite, Seesmic, or UberSocial, two major changes are likely. First, you will soon be able let your app refresh the Twitter stream more often than before without running up against Twitter’s rate limit. The rate limit is the number of times an app can request data from Twitter per hour or day, depending on the type of data your app requests.
Twitter’s current limits only allow apps to grab data 350 times per hour for all data types including direct messages, profile information, and new tweets. That rate will now change to 60 times per hour (once per minute) for each type of data, and up to 720 times per hour for the more popular data requests including new tweets.
As a result, you should see fewer error messages saying that your tweet stream can’t be refreshed or a search can’t be carried out and suggesting you try again later.
Artificial Limits
Twitter is also clamping down on third-party apps by imposing a 100,000-user limit on Twitter client software. Let’s say a company called Awesome Apps Inc. launches Big140, a brand-new Twitter client, on Friday. Big140 could never have more than 100,000 users unless Twitter gave Awesome Apps permission to expand Big140’s user base. Considering that Twitter in March 2011 warned developers to stop making Twitter clients, I am guessing the company will rarely, if ever, allow third-party Twitter clients to expand.
The problem is there are already third-party Twitter apps with millions of users. App maker OneLouder, for example, has between 5 and 10 million installs on Android alone for its Twitter client, Tweetcaster, according to stats Google Play.
Twitter will soon cap apps like Tweetcaster at 200 percent or double their current user base as of August 16. So if we imagine Tweetcaster had 20 million users on Thursday, then the app would max out its user base at 40 million users. As with newer apps, Twitter could give OneLouder permission to expand its user base beyond the imaginary 40 million user limit.
Doubling your user base is no easy feat, especially with the vast array of third-party Twitter clients to choose from, so it’s unlikely these apps will max out anytime soon. At some point in the future, however, a few Twitter clients may have to start offering wait lists before accepting new users or figure out some other remedy to deal with the new user cap.
Twitter plans a few other changes, such as how applications must authenticate with Twitter, but for the most part rate limits and a potential freeze on third-party Twitter clients are the ones with the direct effects — and biggest concern — for users. Twitter’s API changes could also cause developers to be wary of adding Twitter integration to apps or cautious about adding features that use Twitter data. Then again, the improved rate limits and Twitter’s attempt to move developers away from third-party client software could spark new ideas for how to use Twitter beyond simply sending and receiving tweets.
Twitter’s new API will launch in the coming weeks, and once released developers will have six months to comply with the new rules.
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