AppNexus has had REST APIs available to customers for years. We've long had an open platform in the sense that any of our customers could build on our APIs, but our documentation hasn't been searchable or shareable unless you had a customer login.
Today we're changing that by making our REST API documentation available to the open web.
You can read the API docs here: The AppNexus API
As our CEO Brian recently wrote:
.. the Programmable Age ... requires an open ecosystem - namely, platforms with open APIs that foster innovation rather than preclude it.
Opening up our API docs moves us closer to that ideal. You'll still need an AppNexus account to authenticate with the API, but now you'll be able to search our API documentation using your favorite search engine and share links with colleagues and customers.
We hope this helps you build something great.