REST API design practices

APIs allow our application client to communicate with the server. Writing a well-structured API makes it much easier to maintain and consume. RESTful APIs make use of the existing HTTP protocol for communication between two systems.

Receive and send data with JSON

A REST API must be designed to accept JSON and reply to requests in JSON. After making a request, change the “Content-Type” in the response header to “application/JSON” to guarantee that our client can understand JSON. (For more information, check out this page on JSON syntax.)

Proper versioning

Versioning is vital. Versioning refers to how we communicate the changes we make over time. Simply changing the name of a parameter, for example, could result in the creation of a new version. This is good practice because creating a new version informs the developer of the changes we make without breaking changes. Semantic versioning is the most common type of versioning. An example of this is 3.0.7, which indicates a major version 3 and the 7th patch. For example, we can version our API by including “/v1/” (and subsequent versions) at the beginning of the API path.

Providing proper documentation

Documentation provides a better understanding of our API. Documentation contains instructions on how the API should be used or integrated into a program. It also contains details about the API change history and lifecycle. Examples of tools for documentation include Swagger and Postman. Proper documentation should contain:

  • All the necessary endpoints
  • A list of possible error and success messages
  • Examples of requests and their responses
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Don’t use verbs in URLs

REST makes use of HTTP. Including a verb in our URL is not recommended because HTTP already describes what our URL does. HTTP has methods (verbs) such as GET, POST, PUT, PATCH, and DELETE. Make use of nouns instead. For example, we can avoid “/users/retrieveAllStudents/” and use “/users/students/” instead.

Standard error codes

HTTP error codes inform us of what’s going on. Error codes and messages enable us to figure out what’s wrong and how to fix it. We have a few standard HTTP error codes:

  • 400 Bad Request: A result of incorrect client input (incorrect syntax).
  • 401 Unauthorised Access: Authentication is required and has failed or hasn’t yet been provided.
  • 403 Forbidden: The client is unknown to the server and lacks the necessary access.
  • 404 Not Found: The server can’t locate the requested resource.
  • 429 Too Many Requests: This is a rate-limiting technique. This status code means that a user has made too many requests in a short period. An example would be clicking the login button ten times in one minute.
  • 500 Server Error: The server has encountered an unexpected error, resulting in the request not being completed.
  • 503 Service Unavailable: The server is unable to process the request.
  • 504 Gateway Timeout: The server is serving as a gateway and is unable to receive a response in time for a request.

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Secure data with SSL certificates

Most data transferred over a network is private. As a result, it’s critical to maintain the security of data in transit and storage. To achieve this, we use Secure Sockets Layer (SSL) certificates. Their primary responsibility is to establish a secure connection link between the server and the client.

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Monitoring

It's important to include all types of monitoring to improve the quality and performance of our API. We can do this with status codes, response time, network bandwidth, request time, and more.

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Caching

When designing an API, we should design them in such a way that the API caches data that’s already in the local memory. The caching mechanism speeds up the retrieval process. Why? Because it eliminates the need for the API to retrieve data from the database each time. Yes, the cached information will become obsolete over time, but it’s critical to keep the necessary parameters up-to-date. And caching software can help.

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In conclusion, following best practices when designing a REST API is critical because it not only makes our code more presentable and readable, but also makes it industry-standard, scalable, and fast. Remember that an API is a developer’s interface, so in addition to making it functional, it’s critical to ensure that it is well-written and understandable.