Design and Build Great Web APIs

Good APIs begin before the first endpoint is written. In Design and Build Great Web APIs, Mike Amundsen lays out a practical path from understanding what people need to designing, building, testing, securing, and deploying an HTTP-based API. The emphasis is not just on implementation: it is on making clear decisions early and carrying them through to a working service.

Using a continuing API project, the book connects API-first thinking with a repeatable Sketch-Design-Build approach. The examples and chapter exercises give readers a chance to work through those decisions rather than treat API design as a set of abstract rules.

Start with the people and the problem

The opening chapters establish API-first practice and explore HTTP, REST, and the different styles and protocols used for web APIs. From there, Amundsen shows how to model an API around the work it needs to support, then shape that model into a design developers can understand and use.

Make the design visible

Sketches, sequence diagrams, and machine-readable descriptions each help clarify a different part of the design. The book introduces API description and prototyping approaches, including ALPS and OpenAPI, and shows how a design can be examined and refined before it becomes production code.

Carry the work into implementation

The build material uses JavaScript and as it moves from prototype to implementation. Later chapters address testing, security, deployment, and modifying APIs—important parts of treating an API as a service that must remain reliable beyond its first release.

A guided, hands-on read

Worked examples and chapter exercises accompany the book’s progression, giving readers a practical thread to follow from initial modeling to deployment. It is aimed at developers and others involved in API design who want a structured view of the full process, whether they are establishing their approach or revisiting the fundamentals.

For readers who want to connect API decisions with the code and operational steps that follow, this book offers a clear route through the work.