Netflix has announced that it will change both its public application programming interfaces (APIs) and the terms of service to access them, essentially locking away users’ rental history data and preventing them from using third-party applications to export it. At the same time, the company is making it harder for developers to integrate information from Netflix’s API with data from other services as the company maneuvers to keep users within its own applications.

On October 12, when Netflix aborted its spinoff of the physical disc rental business under the new "Qwikster" brand, it announced that the company’s public API would continue to support DVD-related features (after previously announcing they would be retired as part of the split). But now Netflix is splitting its disc and streaming “catalog” databases, and dumping much of the metadata that developers had depended on from both the DVD and the streaming APIs. The functional changes eliminate nearly everything related to users’ viewing history, including rental history, when rented disks are shipped and returned, when streamed films are watched, and the bookmark information for streamed videos paused in progress.

The changes, most of which go into effect this September, were announced in Netflix’s developer blog on June 15 by Daniel Jacobson, Netflix’s director of engineering for the API. In part, they’re driven by the shift in Netflix's strategic direction away from its movies-by-mail business and towards streaming movies, television shows, and its own branded content. But they also appear to prevent developers from using the Netflix library to aggregate a user's movie-watching history across competing services (combining Netflix and iTunes data, for example)—and to prevent developers from essentially wrapping Netflix’s API as their own paid service.

The post generated an immediate negative reaction, with some developers convinced that Netflix wants to cut off their air supply. One developer commented publicly on the changes, saying, “In essence, all the API stuff that third-party developers use to make value-added applications that work better than Netflix’s own site... is going away.”

The changes to the terms of service initially appeared even more hostile to developers, placing restrictions on the packaging of Netflix data as a paid service. That prompted a blog post by social movie rating site Goodfil.ms co-founder John Barton, in which Barton wrote, “The first implication of these additions: if you decide you just want to create a 'Netflix' app, and add significant value on top of the Netflix service, you cannot charge your users for that value. You can do something positive for Netflix, but not for yourself. There is no incentive for you to build something useful for Netflix customers, and if you’ve already built your app, you have three months left.”

But Netflix has indicated the terms of service changes aren’t targeted at “consumer-facing” apps. Instead, they’re intended to prevent developers from repackaging the API as a service for connected televisions or other websites to extract content from Netflix to populate catalogs or act as the primary source for a content search engine.

Still, there’s reason for developers to be suspicious of Netflix’s intentions after the company’s move last year to shed its disc-by-mail business. The company has swerved with its API plans a few times, and had begun to remove functionality from the API even before the June 15 blog post.

In May, for instance, Netflix also dropped information about when a movie would expire from Netflix’s streaming library. The “available until” information was modified to show all films as being available until January 1, 2100—until two weeks before they expire, when the actual date will be displayed. And as of today, the company has also retired the “App Gallery” it had created to highlight third-party applications using its API. Netflix said that the gallery was being retired because “these pages were outdated and seldom used.”