Many talks discuss REST as if that is all you need to know when building an API. It's a good start, but once you try to build something that works, you will soon discover that it takes a lot more than good resource-centric URL design and HTTP verb use. In this talk, I will discuss what is involved in building an API so you don't need to discover it by yourself. The spectrum ranges from a brief recap of RESTful principles through to handling metadata and even (horror of horrors) documentation. Learning about these fundamentals will allow you to prepare your design before writing a single line of code. You can plan development with this in mind, allowing you to deliver a more capable and flexible API to your customers from day one. It can also make it easier and more enjoyable for people to build against your API, encouraging the growth of applications and an ecosystem around it. This talk has evolved from my own experience as both an API consumer and creator. Slides: https://speakerdeck.com/dmi/api-design-its-not-rocket-surgery-phpuk13