The API Design Method

Steps of the API design method

An important way to bring consistency and compatibility to our APIs is to use a common design method or process. Doing this means all API designers go through a similar process, answer the same basic questions, provide recognizable solutions, and end up creating common results. These similarities make it easier for developers and other people involved in the work of building and releasing the API. When the time comes for others to use our API, they’ll recognize similar design details and common implementation elements from other APIs they’ve already used within the company.

The process described below is the one that has been used for many years with good success. It assumes that we’ve gathered lots of information from the key stakeholders, we have copies of the forms and worksheets, and we’ve built up simple flow diagrams and other assets. With all that in hand, it’s now time to turn our interviews and information into an API design.

This API design method consists of four steps:

1. Descriptor: Review all the names of the data and action elements and, where needed, convert them into the names already understood in the API program.
2. Diagram: Convert notes on workflow and internal cycles into something visual people can understand.
3. Definition: Create a machine-readable API definition document that developers can use as a starting point for their implementation.
4. Documentation: Write basic reference documentation for both service developers and service consumers (those using the API in the future).