New Twitter API Drops Support for RSS, Puts Limits on Third-Party Clients

Twitter officially unveiled version 1.1 of its API Wednesday, deprecating support longstanding features such as RSS in the process.

Twitter announced its new API back in August, which it described as helping create "a consistent Twitter experience" across platforms and devices.

Although most of the API changes were previously announced, the overview of the final API highlighted some that were previously unknown. The one sure to cause the most immediate frustration: Twitter is ending support for RSS, XML and Atom.

While it was easy to see the loss of XML coming — Twitter has slowly dropped support for XML in favor of JSON over the last year and a half — dropping support for RSS and Atom is a major shift.

RSS and Atom are the two major formats for serving up web feeds. These feeds can include text, audio, video and other types of media. While most users use RSS as a way to subscribe to web content from a blog or podcast — the format can also be used as a way to subscribe to tweets.

Since its inception, Twitter has allowed developers to access Twitter timelines and search queries using RSS. As a result, lots of social aggregators have used RSS as an easy way to pull in tweets alongside messages for other services.

Many early lifestream services — including things like FriendFeed (which Facebook purchased in 2009) — used RSS as a way to pull in and cross post Twitter updates.

Most aggregation apps can be rewritten using Twitter's 1.1 APIs, but its important to note another change: Twitter's 1.1 API now requires authentication via OAuth 1.0a for all endpoints. In other words, if developers want to get data out of Twitter — they must use OAuth.

The OAuth requirement has the potential of stopping abusive behavior — but it has another side effect too — it means Twitter can control and monitor who is using its data and how that data is being used.

Apps that use RSS, XML or Atom will need to shift to JSON or other API methods by March 5, 2013.

How Will This Impact End Users

Twitter says that RSS usage of its API was low, though it isn't clear how many apps and services pull data or feeds in in this way.

One use of RSS was as a way to display a stream of tweets from a user or a hashtag as a widget on a website. The deprecation of RSS support makes another Twitter announcement — the ability to build user and hashtag based timelines — make a lot more sense.

The new Twitter timeline feature makes it easy for users to create embeddable timelines of events or interactions. This isn't overtly different from Twitter's longstanding Twitter update widget for websites — except that it can now pull in full conversations, as well as search queries for certain hashtags.

That's a relatively benign switch – but the broader ecosystem impact of dropped RSS support will not be apparent until the API changes become mandatory on March 5, 2013.

More Changes for Twitter Apps

As we noted last month, some of the changes coming to the Twitter API have rubbed developers the wrong way. Developers were particularly vocal about the limit on user tokens for Twitter apps. In essence, Twitter is capping how many users an app can have — or at least, that's how it seemed.

In its announcement releasing the final 1.1 API changes, Twitter clarified that the 100,000 user token limit "applies only to the small set of clients replicating the core Twitter experience." (emphasis theirs)

Essentially this means that if your app isn't a client — or you're a Twitter Certified Product — the user limit should't apply.

Twitter clients will have to deal with more than just a theoretical user limit. Twitter's updated Rules of the Road Summary for developers and API terms make it clear that that the service intends to crack down on the freedom currently enjoyed by some third-party Twitter clients.

The biggest change that caught our eye was this:

"Don't resyndicate data. If your service consumes Twitter data, don't take that data and expose it via an API, post it to other cloud services, and so on."

In other words, a Twitter client can't also post Twitter content onto another service. This could be problematic for some of the cross-positing apps on the market — as well a number of IFITTT recipes.

Moreover, taken at face value, it appears that information contained within a tweet — such as a URL — cannot be sent to another service using a third-party client either.

I frequently send URLs I run across on Twitter to Pinboard and Instapaper, often using a feature built-in to my favorite Twitter clients.

This could be problematic for social news aggregators such as paper.li, Postano and RebelMouse. We've reached out to Twitter for clarification on its resyndication policies but have not heard back at press time.

Twitter has spent much of the summer closing off its social graph to apps such as Instagram — and disallowing services such as LinkedIn from displaying user tweets.

When Flipboard CEO Mike McCue resigned from Twitter's board of directors, some speculated that the much-loved app might be losing access to Twitter.

Twitter's new API terms could potentially limit how Flipboard is able to pull in data from Twitter streams.

This is the sort of change that could have a much larger impact on the entire Twitter ecosystem. Sure, it might just be developers and power users complaining now — but if Twitter is serious about these resyndication rules — lots of very popular, very mainstream services could be affected.

What do you think of Twitter's new API changes and the deprecation of RSS support? Let us know in the comments.