What Is API Documentation and Why Is It Important

Amrit Singh
2 min readOct 28, 2022

Nowadays, APIs are everywhere. You can notice this acronym in all areas that have something in common with, for example, mobile applications. Moreover, it concerns various software products — e.g., online shopping stores and payment service providers. If such products need API, then clear documentation is required.

What Is API?

Application Programming Interface (API) is a way to integrate applications. In other words, API is a set of functions and procedures in which different programs can interact with each other. APIs are used in a variety of fields as follows:

  • Payment apps.
  • An acquiring bank.
  • P2P services.
  • Security issues.

For the API to work effectively, there is special documentation that describes all technical processes in detail. The more information the documentation has, the faster the product integration is.

Why Is API Documentation Important?

Integration of a ready-made software product is complex because all further success depends on it. Software components provide data sending in manual or automatic mode. The transmission speed of this data and its correctness are important for the further success of the entire software product.

API verifies the integration of one system into another. For example, a customer of an online store may notice this on the example of the implementation of payment instruments on platforms. API documentation is required to integrate payment apps because, otherwise, the data will not reach the payment system from the online store.

Such documentation regarding payment service providers and acquiring banks plays a significant role in the interaction of several unrelated systems. For example, the API description contains the available endpoints, their detailed description, work schemes, examples of requests and responses, callback structures, and lists of mandatory parameters for specific requests.

In other words, without API documentation, the two systems will not be able to interact with each other correctly since the entire mechanism of integration and interaction must be described in detail, taking into account the “corner cases.”

High-quality API documentation is also essential due to statistics. Services can collect various statistical data that are important for market analysis, creating a portrait of the target audience, monitoring the platform’s effectiveness, etc.


Keeping APIs up to date is essential for products because the documentation becomes outdated quickly. For example, this may happen due to code updates. If this has happened, then the API documentation is no longer relevant. So pay attention to your technical documents and update them regularly.