REST ( Representational State Transfer) is a popular architectural style for developing integration and enabling transfer of data between the integrated systems or applications in a standardized manner. REST APIs also known as RESTful APIs are widely used in modern businesses to enable sharing digital assets capabilities to achieve diverse business goals. REST Services or APIs are designed and developed using different types of technologies and tools and they provide sophisticated methods of integration. During API-Led connectivity projects in any organization, REST API Best Practices to Design, Develop RESTful Services is always among the top concerns and major architectural decisions. If APIs are designed and developed by strictly adhering to API Design Best Practices;  only then the true benefits of API Led Connectivity can be achieved.

In this article, I will discuss about REST API Best Practices in Detail. You will learn about how to use these RESTful API Best Practices to Design, Develop RESTful services which are efficient, resilient, scalable, secure and standardized.

REST API Best Practices: A Journey towards Efficient Integrations

REST is everywhere but REST APIs without following best practices will not help your systems and its users to have a good rest–rather it will cause unrest everywhere ! APIs expose underlying services and associated digital assets (resources). It is extremely important that you make your resources available to the API clients in a right way so that true potential of your services can be reached. If you don’t stock to the standards and best practices when designing and developing your RESTful APIs; the cost of maintenance, upgrades, fixes, acceptability of your APIs will be much higher down the road and you will face a hard time pitching your APIs to the potential customers.

RESTful API Best Practices are summarized below:

Design and Develop APIs Around Standards

The idea of Enforcing best practices for your APIs comes into play from the very beginning–when designing API Specifications. Whether you are using tools like Stoplight Studio or Swagger Editor or you define your APIs blue-print in any other way; adhering to the standards is crucial.

You should build specifications of your API by properly defining resources, methods based on HTTP Verbs and proper standardized response codes in accordance to HTTP Standard set of codes.  It is also important to make your API Specifications as rich as possible by using proper attributes and properties. E.g. use of enumerations for some specific field’s possible values; use of regular expressions for validations, well-defined data types for each field including specification about acceptable date and time formats, numeric values precision levels, max and min length of each field etc.

Additionally, how you do model mappings for request and response structures during API implementation is also very important. Mappings should revolve purely around business needs and you shouldn’t limit your decisions based on technical factors (e.g. it is insane just to map an entire table to a response for your own technical ease or convenience).

REST API Best Practices for Naming Conventions

Just like you care so much to name your baby or your pet; a proper standardized name of each and every building block of an API really matters. Naming conventions are a set of standards for APIs in general and for any organization in specific which should be followed to have a better picture of your APIs.

When naming resources, methods, data elements etc. follow the standards and naming conventions properly. E.g. resources in any API should be named as nouns and not verbs. For OrdersAPI, resource name should be orders and not generate-orders or handle-order!

Also, for any collections, plurals should be used instead of singulars. orders is the right naming choice instead of order! for single order, path parameters will serve the purpose like orders/123 for an order with order id 123.

HTTP verbs like GET, PUT, POST, DELETE, PATCH will serve the right purpose and let the API developers know what kind of action is required.

Use proper HTTP Methods (verbs) with properly defined parameters. Path parameters as kebab case (with a hyphen as separator) and query parameters with snake case (having underscore as a separator) can be used as a naming convention for your APIs. Elements in the JSON structure of your request and response model should also follow proper naming conventions: snake case for element names (e.g. user_role).

It is important to mention here that in any organization; some locally agreed standards can also be enforced and used for the entire API eco-system in that organization.

Remember: Conventions are not Rules !

REST API Best Practices: Tackle All Error Scenarios Properly

Errors are a bitter reality and no system on earth is 100% error-free. Errors can occur for different reasons in your APIs and you need to ensure that you follow best practices during your API’s design and development.

It is important that you handle all types of exceptions and return proper well-defined and agreed error codes and error messages. Your API should never return back internal details of your system or internal stack traces in the response no matter how and at what point your API broke or failed.

Errors should be logged in a proper manner with all relevant details. With proper referencing/correlation; it should be possible for any developer to track and trace the logs and find meaningful information as and when required. It is also important that you should log only what’s required to be logged–nothing more, nothing less.

API Security Best Practices Must be Followed

Security must be treated as the top concern when exposing APIs. Through APIs, you are essentially opening a door to your back-end systems and hence this door must be safeguarded in every possible manner. API Security Best Practices must be followed when designing APIs, implementing APIs and exposing those APIs.

Use of SSL to have HTTPS based secured data transmission over the network is a primary step in this regard. Avoid using self-signed certificates and always opt for CA Signed, strong-cipher certificates. In some scenarios of B2B integrations, Mutual (Two Way) SSL option can also be considered.

Use Authentication and Authorization Schemes to decide who can reach the services and what can be accessed. Use of API Keys, OAuth, JWT, SSO, SAML etc. mechanism for Keys Activation, Revocation, Refresh should be properly considered.

On top of this, use of API Management Platforms can also greatly help achieving better API Security. API Management Platforms provide a rich set of Security Policies. Using these policies and configuring them in a right manner, can help safeguard your APIs in a better and well governed manner.

Recommended Reading: How API Management Platforms Help Dealing with API Security Threats

Performance is the Key: Focus on API Performance

APIs are implemented to help applications communicate data in a synchronous manner in a quick and efficient manner. Performance of an API should be thoroughly considered when designing and developing it. No one likes an API that can’t return desired response in a matter of few milliseconds or at max a few seconds. A better user-experience isn’t possible with an API that takes minutes before returning a success response.

Ensure that your API’s implementation and its underlying database systems and any other inter-linked services are efficient enough to have better response time and higher throughput. APIs should be kept with as limited dependencies as possible to rightly benefit from Microservices Architecture.

Keep the data associated with the API’s request and response models as limited as possible. Expect only what’s necessary and return only what’s needed. Additionally, providing filter, pagination, sorting related features in your API can greatly help clients to get required data in a faster and efficient manner.

Caching is another option to respond faster to the clients for some specific API resources. As an example, if an API returns daily price information; it makes sense to cache that once and respond to API calls from cached data for the whole day instead of hitting back-end system for every single call to get same information.

Document Your APIs Properly

APIs are meant for developers who will use your APIs to implement applications. API’s documentation made available to API Clients is very important as it will set the ground for the clients to understand how your APIs can fit into their needs. Your API Documentation should be clear, concise and up-to-date. From your API documentation, all aspects of your API including request, response models; response codes, required parameters, security schemes etc. should be clear.

 

 Video: REST API Best Practices

REST Best Practices have been discussed in detail in my below video on TutorialsPedia YouTube Channel.

If you have any questions, comments, feedback; feel free to write below in comments section.