I am the author of two books: Learning CFEngine and Learning Hammerspoon, both self-published using Leanpub. The source of my books is kept in GitHub repositories. In this post I will show you how I use the Leanpub API together with Hammerspoon and CircleCI as part of my workflow, to automate and monitor the building, previewing and publishing of my books. The Hammerspoon section of this post is Mac-specific (since Hammerspoon is a Mac-only application), but the integration between GitHub, CircleCI and Leanpub can be applied regardless of the OS you use.