API Strategy & Practice Conference 2018

Hyrum's Law states that "With a sufficient number of users of an API, all observable behaviors of your system will be depended on by somebody." This observation is catastrophic to the idea of a REST API that can evolve independently from its clients.

Once a client is released that relies on observable attributes of an API, the API instantly becomes hard to change. The API can then quickly become littered with deprecated properties, kludges, and violations of the advertised media type. These quirks are observed by new users of the API, compounding the issues. The result is an API where change becomes risky rather than routine, not the decoupled and evolvable APIs promised by Hypermedia.

In this talk we will explore why clients misuse REST APIs and what strategies, both social and technical, we can utilize to fight back against Hyrum's Law and unlock the power of Hypermedia in our APIs.