Tornado is a Python Web framework and asynchronous networking library that provides excellent scalability due to its non-blocking network I/O. It also greatly facilitates building a RESTful API quickly. These features are central to Tornado, as it is the open-source version of FriendFeed's Web server. A few weeks ago, Tornado 3. was released, and it introduced many improvements. In this article, I show how to build a RESTful API with the latest Tornado Web framework and I illustrate how to take advantage of its asynchronous features.