Principles for Designing APIs Effectively

APIs play a key role in the software application development and those are different protocols that help the software applications to communicate. While REST API are widely used and requests based on HTTP, we need to follow design principles during development and quality validations also be compliant with that.

Here I am mentioning about various design principles that help the REST APIs to be effective all that I learnt with my experience and learning across various sources.

1. Define HTTP Methods based on right action and ensure reliability.

While defining HTTP methods based on the actions to retrieve or create or update follow reliability and consistency.

2. Versioning — New API versions without impacting current consumers

API versioning is needed to maintain backward compatibility and allow API improvements for new features or bug fixes without breaking existing features or applications.

This can be achieved through URI versioning / Header versioning/ Query versioning or other ways.

URI Versioning : /api/v1/resources → /api/v2/resources

Header Versioning : Custom header : accept-version:V1

Query Versioning : /api/resources?version=1 → /api/resources?version=2

3. Data Sets effective management — Pagination/Filtering/Sorting

While data response is huge with the request made and better performance , user experience for the clients is always vital.

Effective usage of pagination, filtering and sorting will help in improving performance and user experience.

With all possible combinations of above here is the example :

GET /api/resources?category=network&provider=cisco&sort=provider&page=1&per_page=20

4. Use clear naming preferably plurals of nouns for collections in URIs. This helps in better readability and predictability.

5. API Security :

While designing APIs , security is an essential aspect as it helps for protecting sensitive data and also tampering and unauthorized access.

Below are techniques for achieving maximum security across APIs.

6. HTTP Status codes with response :

The expected response code of a HTTP request is important while understanding what is happened with the request. Below is the summary of responses with examples and usage. If developers did not have a proper understanding of expected outcome, it might lead to wrong usage and vulnerable to defects while integrating across many layers of application.

7. Effective Error Handling

While in the above section clearly mentioned about providing proper HTTP status code in the situation, below are few advices to handle errors better readability and understanding to make fixes faster.

8. Usage of Hyperlinks in the REST API response

By placing Hyperlinks in the REST API response, clients can navigate dynamically and discover resources and actions with self-descriptive. It also helps through flexibility , error handling and simplifies pagination. Below table summarizes the usage of hyperlinks in places.

I am sure that by incorporating above principles of effective APUs, can help in improving the better apis for readability, usability , performance and better error handling.