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App Development
6 minutes read

How to Build an API

By Jose Gomez
By Jose Gomez
App Development
6 minutes read

If you want to build your own API for your organization, you will likely be interested in learning more about API development. APIs form the backbone of modern web and app development

With an API, third-party tools and features can be integrated with custom web and mobile apps. In addition, APIs facilitate the communication and data exchange between apps and enterprise systems. 

Learning how to build an API could be vital for your organization’s business capabilities and internal developers. 

This post will help you understand what goes into API development and help your business craft an API strategy that will improve the quality and capabilities of its software. 

Building Your Own API: 5 Key Steps

API users demand APIs that function properly and accurately exchange data. Whether your organization wants API developers to build APIs for internal uses or create a public API, there are five critical steps to create APIs. 

When building APIs, the five vital steps that your organization must consider to ensure long-term success are:

  • Focus on goals and users
  • Choose an architectural style
  • Develop your API
  • API testing 
  • Monitor and Iterate 

Focus on Goals and Users 

Your API should bring value to its users and your organization. Therefore, before you can create an API, you should clearly understand who the target end user is and the organizational goals driving development. 

For example, if you want to create private enterprise APIs to connect data tools and share data models internally, the target users you are building for are your organization’s internal engineers and developers. 

It should be easy to understand these developers’ needs and how to meet them since you have direct access to their feedback and thoughts. 

To create an API that anyone can use, you’ll need to do more work to understand your target audience. The focus should be on creating a positive developer experience and providing value to users. 

If you create an API for public consumption, you will also have to provide API documentation, SDKs, and other API resources to ensure that the API works as intended. 

Choose an Architectural Style 

Before a single line of code is written for your API, you need to choose an architectural style that not only fits the functional requirements of the API but also meets the needs of the developers who will be using it. 

The two main architectures many APIs utilize are SOAP and REST

SOAP is an official protocol with firm guidelines. While REST, on the other hand, is flexible architecture with several loose guidelines. 

SOAP works with application layer protocols like UDP, SMTP, and HTTP. On the other hand, REST only works with HTTP methods.

REST enables APIs to cache requests. SOAP does not allow an API request to be cached. In addition, SOAP requires detailed API contracts, and REST does not. 

SOAP has built-in authorization, security, and error-handling features. However, development teams must handle these critical concerns independently when using REST. 

REST utilizes various data formats, including plain text, HTML, XML, and JSON format. SOAP uses XML data exclusively for communications. 

SOAP is more secure and offers excellent extensibility. On the other hand, REST offers greater API performance, scalability, and unmatched flexibility.

If mobile and web apps are your main interest, REST APIs will be a great option. However, if you are more interested in legacy and enterprise applications with more significant security needs, SOAP APIs will be the better choice for your API. 

Develop Your API 

Once an architecture has been chosen for your API, it is time to build it. The most effective way to develop an API is one API endpoint at a time

By developing an API in this manner, you can ensure the API interface is functioning properly, one feature at a time. 

At this point, it will also be vital to define what a successful status code response is for your API. Examples of a status code are 404, resource not found error message, and 201, resource created OK. In addition, there are several other status code variations your development team should be familiar with. 

In addition to defining successful status codes, your development team must determine the type of request your API endpoints can receive. 

Common API Requests

When data moves from one endpoint to another, it needs to know what action to take. For example, there is GET request, POST request, PUT request, PATCH request, and DELETE request. 

The GET method is considered the most secure request for an HTTP client because it cannot modify data stored in your database. However, other API requests can edit information from other endpoints and databases as needed.

After each endpoint is developed, it is vital to ensure that it functions as expected for API users. 

Don’t Forget to Write API Documentation

Documentation is a critical part of creating an API. Documentation should provide other development professionals and users with the data they need to successfully use your API.

Examples of the information that should be included in the documentation are:

  • The API authentication scheme
  • Supported requests and responses 
  • Error descriptions
  • Endpoint definitions 
  • All other interfaces, exceptions, constructors, and classes

Documentation is less vital to a private API. However, public-facing APIs need strong documentation, or they likely won’t be widely adopted and used in the API gateway of third parties. 

API Testing 

Test your API to ensure it functions properly and doesn’t negatively impact the User Interface of target applications. You can test an API locally before development is complete using API virtualization. 

Not only will you want to test the programming languages and code for bugs and errors, but you will also want to test the API for functionality, reliability, security, load capacity, integrability, and more. 

Here are some tips when you want to test a new API:

  • Test each API function in isolation
  • Test the API under a variety of common network conditions
  • Simulate errors
  • Don’t use live APIs for testing 

Monitor and Iterate 

At this stage, your API will be deployed to production. However, you still have work to do once your API is released. Monitoring API performance and iterating to improve performance and add new features is vital

Several tools enable businesses to monitor the performance of their API. Therefore, it is critical to consistently iterate and improve your API product. 

Many APIs are sold to the public. Users need an API key to access your API. Unfortunately, users don’t pay for API keys when the product fails to live up to expectations. 

No matter what your ultimate goals are for your API, development doesn’t end with deployment. There is always more work to be done. 

Final Thoughts 

Creating an API is easier than building an application or website, but it still requires detailed work and research. If you want to learn more about creating an API, reach out to a skilled app development partner.

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