Top 4 Tools for Developing APIs
What should you use to build your API? Application Composer, Swagger, Postman or REST-Assured
APIs (Application Programming Interfaces) are the backbone of building efficient and scalable software systems.
Simply put, an API is a modular component that helps you streamline intra-app/inter-app communication.
Thus, selecting the correct tools for developing your APIs can be a critical task that directly impacts the overall success and productivity of your entire project.
Therefore this article will be discuss four tools that you can use to develop, manage and deploy your API while covering their key features, pros and cons so that you have all the information that you need to pick the correct tool for the job.
1. AWS Application Composer
AWS Application Composer is a no-code tool for modern API designing. It lets you design an API in under 2 minutes. Check out the figure below:
Application Composes provides you with a blank canvas where you can drag and drop components from over 1000 services such as DynamoDB, Lambda, SNS, SQS, Cognito, API Gateway, S3 and more. Next, you can connect your services using the canvas to help them communicate with each other.
Behind the scenes, Application Composer manages a CloudFormation template that manages everything you do on the canvas. So all you have to do is, take that template and deploy it through the SAM CLI and it’ll provision your infrastructure in the cloud in under 5 minutes.
Pros
- Simplifies the entire API design and development process with the visual interface. That, in turn, makes AWS Application Composer easily accessible for developers of all skill levels.
- Seamless integration into the AWS ecosystem.
- The generated templates follow development best practices.
Cons
- Developers need to have knowledge of AWS SAM for deployments.
- The service can appear to be limiting for applications that require a higher level of customization, but it can also be overkill for simple API projects.
2. Swagger
Swagger is undoubtedly a key documentation tool for APIs, popular and widely used within the software industry. It is a powerful tool that helps you design, develop, and document RESTful APIs and is an integral part of the OpenAPI Specification.
Its key feature that has garnered the attention of developers worldwide is its exceptional capability of generating interactive API documentation that allows developers and users to understand and test the API endpoints directly from the browser.
The robust collection of tools Swagger provides caters to various aspects of building and managing APIs, making it stand out as a reliable tool for creating clear, interactive, and scalable API interfaces. Some examples of such tools include Swagger Editor, Swagger Codegen, and Swagger UI for various requirements such as designing, building, consuming, and documenting, respectively, when dealing with APIs.
// sample Swagger configuration
const swaggerJsdoc = require('swagger-jsdoc');
const options = {
definition: {
openapi: '3.0.0', // Specification (optional, defaults to swagger: '2.0')
info: {
title: 'Hello World', // Title (required)
version: '1.0.0', // Version (required)
description: 'A sample API', // Description (optional)
},
},
apis: ['./routes/*.js'], // Path to the API docs
};
const swaggerSpec = swaggerJsdoc(options);
module.exports = swaggerSpec;Pros
- Supports multiple programming languages and frameworks, making it highly adaptable and usable across diverse development environments.
- Lightweight and extremely flexible.
- Reliable and have a huge community of developers using it.
Cons
- There is limited support for SOAP APIs.
- Beginners may find the Swagger learning curve steep.
3. Postman
Postman has become an indispensable tool when it comes to developing APIs over the past few years. It is a tool that is mostly known and used for the purposes of testing APIs and saving responses, but it is a highly versatile tool that supports integration testing, API scenario testing, data visualization, and reference and workflow documentation.
Postman helps streamline the whole API development life cycle with its toolset, enabling both novice and experienced developers to enhance their productivity and collaboration. The ease of use and the adaptability Postman provides have made it a go-to environment for API-related tasks, from simple manual testing to complex API test automation. Below is a simple demonstration of how a test script has been written to test the open weather API.
pm.test("Status code is 200", function () {
pm.response.to.have.status(200);
});
pm.test("Response has the correct structure", function () {
pm.expect(pm.response.json()).to.have.property('coord');
pm.expect(pm.response.json()).to.have.property('weather');
pm.expect(pm.response.json()).to.have.property('main');
pm.expect(pm.response.json()).to.have.property('name');
pm.expect(pm.response.json().name).to.eql("Colombo");
});
You can find an entire collection of API tests with Postman, here.
Pros
- Intuitive and user-friendly interface.
- Powerful testing capabilities, including support for writing complex automated tests.
- Allows team collaboration.
- Supports a wide array of HTTP methods, parameters, and headers and supports efficient request-response management.
- Allows developers to simulate API endpoints and responses with mock server functionality.
Cons
- The amount of features and their complexity can sometimes overwhelm new users.
- It can be somewhat memory-intensive resulting in slower performance in some computers.
- Limited browser support.
4. REST-assured
REST-assured is a JAVA DSL (Domain Specific Language) that simplifies testing and validating RESTful web services. It works well with even complex JSON structures and has the capability of fetching necessary data from almost any part of the responses and the requests. In a time where automating API testing is becoming essential, REST-assured undoubtedly becomes a top candidate for a solution given its capabilities to write powerful, maintainable, and highly understandable API tests.
It uses a fluent, and highly readable syntax that comprises keywords such as Given(), Method(), Then(), and When() to set up the test scenario, pass necessary parameters, and define the expected behavior. For instance, given below is a simple demonstration of an instance where REST-assured is used to validate the status code and the content of the response of an HTTP GET request.
import static io.restassured.RestAssured.*;
import static org.hamcrest.Matchers.*;
given().baseUri("http://api.example.com")
.when()
.get("/hello")
.then()
.statusCode(200)
.body("message", equalTo("Hello, World!"));Pros
- Has support for all standard HTTP request types including POST, GET, PUT, HEAD, OPTIONS, and DELETE.
- Allows setting up request specifications such as authentication details that you can reuse across multiple tests.
- Supports JSON and XML response types.
- Can be integrated well with Maven. Supports integration with Java testing frameworks such as TestNG and JUnit.
Cons
- Do not have explicit support for SOAP APIs.
- Requires knowledge and familiarity with Java and BDD framework.
- This may result in performance overhead with complex and large tests.
Wrapping Up
The landscape of API tools for designing, development, testing, and deployment is rich and varying, and it caters to a wide array of requirements and preferences in the domain of software development.
Therefore, it’s important that you understand how each tool works and for what purpose it’s used for. So, I recommend creating POC’s using each tool to evaluate your needs before proceeding with the tool of your choice.
I hope you find this article helpful.
Thank you for reading.
