API Documentation Case Study

The Client

Client is a leading multi channel Bill Payment service provider in North America.

Their service is available from multiple access points such as self-service kiosks, POS/clerk-assisted locations and smartphone applications.

The Challenge

Our client offers multiple applications for users to access their services, such as kiosks and mobile applications. Underneath these interfaces is the API layer which handles all the transactions and communications. Our client would like to allow their customers to build client applications on top of their APIs.

However, they did not have any existing documentation for their set of 40 APIs, so their customers could not reference to any documents when they wanted to utilize the APIs. In addition, they had a shortage of staff, so they could not spare some resources on technical writing.

The Process

  1. Communicate with the team.
  2. Study the APIs.
  3. Create sample documentation for several APIs and get feedback.
  4. Complete documentation for all APIs.

How Optimus Helped

In the beginning, our client gave us an overview of the APIs and their business processes. They also walked us through a couple workflows using the APIs.

Then, we learnt about the APIs on our own. We got an understanding of how to use the APIs by executing their test cases and following their business processes.

We created a sample API documentation using several APIs. For each API, we detailed API description, calling sequence, usage scenario, sample request and response, description of each field in the request and response, error codes and related APIs. We sent the sample documentation to our client, and we asked them for feedback.

After we received the feedback from the client, we incorporated the feedback and generated documentation for the whole set of APIs.

Our client sent this API documentation to their customers as a tool to help them build applications using the APIs. This documentation also became a resource for the developers and QAs.