APIs are critical to modern web applications and software development as they enable data exchange among systems.

However, designing a good API can be tricky, as it requires a good understanding of the underlying process and technology. To maximize the effectiveness of your next API project, you must plan and plan well, dot the I’s, and cross the T’s—if you will—before commencing the design process.

You can always use a no-code tool to build your APIs, but what exactly goes into good API design?

Let’s explore API design best practices that can help you develop APIs that tick all the boxes in terms of performance, scalability, and end-user requirements so that you can deliver a functional and optimized solution for seamless connectivity.

API Design best practices

API Design Best Practice#1: Think From Users’ Perspective

API design best practices include designing APIs while keeping consumer experience at the forefront, making it easier for developers to understand them. Attention to detail is the key here. Here are some commonly agreed conventions that will help deliver a better overall experience for end users:

  1. Keep the verb for Method and nouns for the Resource. Avoid using verbs when defining an API resource. For instance, a resource as api/readOrders is a bad design; instead, the resource should comprise the entity noun along with the method tag, such as GET api/Orders.
  2. Use the correct verb action to define the API method that signifies the purpose of the API. Commonly used standards include:
    • GET: to fetch or read data
    • POST: to insert data to a storage or a process
    • PUT: to completely update data of an existing resource
    • PATCH: to partially update data of an existing resource
    • DELETE: to remove an existing resource

You can also use other HTTP verbs such as COPY, PURGE, LOCK, VIEW, etc.

  1. Choose API default behaviors carefully. For example, API users prefer the favorite payload content-type, JSON, as it’s easy to read and lightweight when transferring data. So, you can set your APIs to accept and respond with JSON.
  2. Consider specific user input when defining responses. An example could be to let the user provide an Accept” input parameter which states the content-type they’d wish to receive their response data in. Incorporating their feedback gives them the flexibility to use API as per their integration requirements.
  3. On the server side, enable standard functionalities by allowing users to filter, sort, and paginate data according to their specific requirements. Modern API Design tools, such as Astera API Management solution, reduce this to a matter of point-and-click by allowing you to dynamically filter, sort, or paginate API responses through a code-free UI.
  4. Focus on developing performance-optimized APIs so there are no issues on the client side, such as unresponsive applications, delayed responses, security breaches, vague error messaging, etc. You can ensure optimal performance by maintaining a response cache to serve common requests faster, optimizing runtime accessing databases, and monitoring the server for scaling needs.

API Design Best Practice#2: Picture What API Functions are Required

  • Organize API resources by maintaining API flows in a project so it’s easier to manage them in the long run. This API design best practice also helps in resource identification.
  • Your API resources should be stated as per the entity (noun), with the API method defining its action method (verb). For example:
    • GET /orders’ Fetch all orders
    • GET /orders/{orderID} Fetch order by order ID
  • Use logically structured nested resources. A customer orders API should validate the relationship that exists between these resources as ‘/Customers/Orders/’
  • Identify logical and definitive subsets of reusable components. APIs are labeled as reusable artifacts that one party develops and shares the functionality or data resource. However, you may need to design various functions or integrations once and share them across various implementations.

API Design Best Practice#3: Evaluate your choice of API Service architecture

The architecture defines the communication style between the various parties involved. It also explains the industry standards an API complies as per its architecture, thus helping API consumers to understand its usage. The industry’s favorite architectural choices are:

  • REST APIs: rest stands for representational state transfer. Rest APIs are used for resource-based data APIs that are easily understood for common platform usage. These resources are backed by a data model that helps derive relationships between various API resources exposed to a user.
  • GraphQL: used for data APIs with more flexibility to query nested resource data in a single request.
  • gRPC: introduced as an effort to improve the performance of API communication between various data services using buffer protocols.
  • Event-driven/Asynchronous APIs: When communicating, all services can run at their own pace and talk when needed, which free up resources as the sender and receiver are not busy waiting for each other’s responses; instead, they only notify each other as the need (event) occurs. Following the API design best practice, consider giving users the flexibility to choose between processing an API request synchronously or asynchronously.

API Design Best Practice#4: Implement to Design

You can design an API with different input types by specifying input parameters and validations.

API Parameters are key-value inputs included in the API request object. One of the best API design practices is choosing parameters and their datatypes wisely as per the resources. This information should be well thought out to stay future-proof, as any changes after publishing can cause breaking effects to all existing API users.

  1. Keep a parameter as URI if it identifies a single resource entity such that every value of the parameter set compiles to a unique API request. For example,

Here the country is a URI parameter that uniquely identifies the resource of this API.

  1. Choose the Query parameter type for data-specific properties such as filters, sorts, and conditional properties. For example, GET: https://myweatherapp/{country}?
  2. Use Header parameters for specifying meta-information about the API request itself and the content type expected to be received. Some examples of data sent as header parameters are connection string, content properties, and cache control.
  3. Each parameter should have a short description to tell users the usage and purpose of the parameter. You may choose to set parameters as a requirement or keep them optional.

In addition to parameters, API communication involves data sharing via payloads. These payloads comprise complex data structures of various acceptable formats such as JSON, multipart, plain text, etc. See the list of all content types here.

API Design Best Practice#5: Thoroughly Test for Accurate Responses

Your API needs to respond with accurate HTTP status codes, including the correct error description, so end-consumers can identify errors and troubleshoot them. For example, a user calls an API to retrieve weather forecasts for a given Country as such:

GET WeatherForecast/Germany.

This API would require users to provide a start date value, and if a user doesn’t provide it, it should result in an error with a descriptive message, such as:

Notice this error message includes all required information, including the missing parameter, location in the request, data type, and format. Moreover, it responds with the standard HTTP status for a bad request, indicating the possibility of an error.

API Design Best Practice#6: Documentation is Equally Important

Rest API design best practices include painting out the guidelines for developers to easily browse and identify how to consume APIs is also important.

You must create a document that complements the functionality and provide complete information about each resource and its parameters. The data structure should be easily identifiable, and users should be able to map information to their existing data or platform knowledge. Clear documentation increases the chances of your API adoption, making API integration easier.

APIs must also provide direct support at the consumer end. For that, you must create a Developer Portal detailing what APIs are published and how to access them. For instance, REST APIs documentation relies on the standard Swagger Open API specification, considered a global language for all API platforms.

API Design Best Practice#7: Keep a Strict Check on your Security Locks

APIs are an integration interface for sharing data with multiple users. These users call the same API to access their data and run processes. Hence, as REST API best practices design, it is integral to contain each user to only access data they are authorized for and limit access otherwise.

Consequently, an interface is vulnerable to security breaches, and the API administrators must control access and ensure data integrity for all users. Commonly recommended authentication types include OAuth2, Bearer Token, and certificate exchange between sender and receivers.

Moreover, API Servers should also be guarded against attacks such as server overload, DDOS, etc., by using policies such as rate limiting.

API Design Best Practice#8: Prepare your Elves for Change Management

Consider maintaining versions of your APIs. As APIs roll out into production and developers start to use and integrate APIs in their systems, they block any room for future change management. So, it’s best to consider versioning from the start. The best approach is adding a version prefix to the API that’s easier for admins and end users to track down. For example,



Simplify API Designing With Astera

Well-designed APIs act as a strong foundation for many apps to integrate. When designed correctly, APIs enhance user experience and open a business to partnership opportunities.

You can implement these API design best practices with Astera’s no-code  API Management solution. Astera has introduced a viable concept to design and implement APIs in a visual interface, which makes it easier to incorporate the feedback of non-developers. The visual interface allows you to build an API flow that ensures the API design complements the logical flow.

Using Astera’s intuitive solution, APIs can be ideated, designed, and tested for improvements as a one-time effort. Astera allows you to build high-end APIs on the go by incorporating a wide range of functionalities supported by its extensive features.

Want to simplify API development, sign up for a free 14-day trial or schedule a demo with one of our experts.

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