
Hello, today we bring you a beginner's guide to using APIs. As we have mentioned in previous articles, APIs are mechanisms that allow two software components to communicate with each other through a set of definitions and protocols. For example, the weather institute's software system contains daily weather data (AWS, 2024).
SOAP API: These APIs use the Simple Object Access Protocol (SOAP). The client and server exchange messages using XML. It is a less flexible API that was more popular in the past.
RPC API: These APIs are called Remote Procedure Calls (RPC). The client executes a function (or procedure) on the server, and the server returns the result to the client.
WebSocket API: The WebSocket API is another modern development of web APIs that uses JSON objects to transmit data. The WebSocket API supports bidirectional communication between client and server applications. The server can send return messages to connected clients, which makes it more efficient than the REST API.
REST API: These are the most popular and flexible APIs found on the web today. The client sends requests to the server as data. The server uses this input from the client to initiate internal functions and returns the output data to the client. Let's take a closer look at REST APIs below.
What are REST APIs?
What is a web API?
A web API or web service API is an application processing interface between a web server and a web browser. All web services are APIs, but not all APIs are web services. The REST API is a special type of web API that uses the standard architectural style explained above.
What are API integrations?
What are the benefits of REST APIs?
- Integration: APIs are used to integrate new applications with existing software systems. This increases the speed of development, since you don't have to write every feature from scratch. You can use APIs to leverage existing code.
- Innovation: Entire industries can change with the advent of a new application. Companies must respond quickly and support the rapid implementation of innovative services. To do this, they can make changes to the API without having to rewrite the entire code.
- Scalability: APIs present a unique opportunity for companies to meet the needs of their customers on different platforms. For example, the map API allows map information to be integrated into websites, Android, iOS, etc. Any company can offer similar access to their internal databases using free or paid APIs.
- Ease of maintenance: The API acts as a gateway between two systems. Each system must make internal changes so that the API is not affected. In this way, any future changes made by one party to the code will not affect the other.

What are the different types of APIs?
- Private APIs: These are internal to a company and are only used to connect systems and data within the company.
- Public APIs: They are open to the public, and anyone can use them. There may or may not be authorization and cost associated with this type of API.
- Partners API: Only authorized third-party developers can access them to assist in business-to-business partnerships.
- API Composites: They combine two or more different APIs to address complex system requirements or behaviors.
What is an API endpoint and why is it important?
- Safety: API endpoints make the system vulnerable to attacks. API monitoring is crucial to prevent misuse.
- Performance: API endpoints, especially those with high traffic, can cause bottlenecks and affect system performance.
How to secure a REST API?
- Authentication tokens: They are used to authorize users to make the API call. Authentication tokens verify that users are who they say they are and that they have the access rights for that specific API call. For example, when logging into the email server, the mail client uses authentication tokens for secure access (AWS, 2024).
- API keys: API keys verify the program or application making the API call. They identify the application and ensure that it has the necessary access rights to make the API call in question. API keys are not as secure as tokens, but they allow you to monitor the API to collect usage data. You may have noticed a long string of characters and numbers in your browser URL when visiting different websites. This string is an API key that the website uses to make internal API calls (AWS, 2024).
NOW THE REAL QUESTION! How to create an API?
1. API planning: API specifications, such as OpenAPI, provide the blueprint for designing your API. It is best to think about different use cases in advance and ensure that the API complies with current development standards.
2. Creation of the API: API designers create API prototypes using reusable code. Once the prototype is tested, developers can customize it to internal specifications.
3. API testing: API testing is similar to software testing and should be performed to avoid bugs and defects. API testing tools can strengthen API testing against cyber-attacks.
4. API documentation: Although APIs are self-explanatory, documentation serves as a guide to improve their use. Well-documented APIs that offer a variety of functions and use cases tend to be more popular in a service-oriented architecture.
5. API marketing: Just as Amazon is an online marketplace for retail, there are API marketplaces where developers can buy and sell APIs. Publishing your API can allow you to monetize it.
What are API tests?
- Make multiple requests to API endpoints to test performance.
- Write unit tests to verify business logic and functional correctness.
- Test security by simulating attacks on the system.
How to write API documentation?
Writing complete API documentation is part of the API management process. API documentation can be generated automatically with tools or written manually. Some best practices include:
- Write explanations in simple, easy-to-read English. Tool-generated documents can be complicated and require editing.
- Use code examples to explain the functionality.
- Maintain accurate and up-to-date documentation.
- Adapt the writing style for beginners.
- Cover all the problems that the API can solve for users.