How to develop an API – Best Practices to Follow from Cyclr Developers

Updated on by Hayley Brown

So you know your API types, but what if you want to develop your own API? A while ago we chatted with our developers about working with APIs, their challenges, and how they like to see APIs built. Which got me thinking, what is the process of developing an API? 

Building an API allows your SaaS applications to connect to other applications, allowing data and services to flow between them. This could be both internally and externally, to your wider ecosystem of applications managed through an Embedded iPaaS

Why are APIs so important?

Let’s start at the beginning, APIs are an important aspect of the modern computing world. According to APIs for Dummies, “application programming interfaces (APIs) are the underpinning of the cloud, mobile and Internet of Things (IoT) revolution.” 

Data is easily, and speedily exchanged through APIs. This allows for modern innovation and daily conveniences. Conveniences include moving money between bank accounts, sharing video moments on social media, seeing this week’s weather, or managing your at home appliances. APIs are connecting us and the world through data. 

Process of Developing an API

As a beginner, it can seem like a daunting process, but developing an API puts connectivity at the forefront of your application. If done correctly APIs enable faster innovation and the ability to reach new audiences. This is a beginners guide if you will, of some of the key steps in building an API, and some API development tools that will give you a helping hand.

API Preparation 

Many resources when researching how to develop an API started with the planning and preparation of the API. As well as the questions you should be asking when initially preparing. For instance, what do you want to achieve with the API and what business capabilities does the API expose to consumers?

Akana mentions several considerations and questions to help determine your APIs requirements.

  • What is the problem the API will fix, at a high level?
  • Who is the audience? (internal developers or external consumers)
  • How can the audience’s needs be incorporated into the API?
  • What are the APIs expectations in regards to performance, response times, and data protection?
  • What needs to be addressed in regards to API security?

Next you’ll need to choose an API architectural style, which could be any of the following.

Design your API

Then the design phase of the API to determine how it will look, as well as processes to make the API easy to understand for users. Creating a useful name and description is beneficial. As mentioned by AWS, a hosting service, “users of public APIs are usually developers, so it is important to build APIs that are simple and intuitive for them.”

Stoplight mentions that it is useful to create wireframes of how the API will be used client-side, which helps guide developers in setting up the API. As well as taking steps to ensure the API is designed with integration and scalability in mind for future growth and development.

A developer portal is a useful resource when promoting your API so it is worth spending some time designing how you want that to look, as well as writing your APIs documentation as you go. 

API Development

It’s time to actually create the API. There are plenty of API development tools available to help build your APIs such as outsystems, and PortSwigger.

Firstly, fill out your APIs user-friendly name, and description, describing the purpose of the API. Then implement important security policies as the API will be dealing with consumer data. As well as specifying the data models that describe the API request and response messages. 

Then create endpoints based on the user’s needs. These are important requirements that need to be met for integration. Especially if you are wanting to scale the API. Including HTTP methods, that correspond to create, read, update, and delete operations respectively. 

  • GET: read or retrieve a single resource
  • PUT: update or replace a single resource
  • DELETE: remove a single resource 
  • POST: create a single resource

As well as including the correct data formats which is important for building APIs for integration. As this is the type of data used by the API. 

  • Json
  • XML
  • Form

For GET, this is the accept header.

For POST, this is the request data.

Authentication is a must for any API, as it is being used to transfer private data and is necessary for any multi-tenant system. A popular authentication type is OAuth. As well as Set up error messages/responses for common errors such as ‘Not Found’, ‘Unauthorised’, etc.

Having a multi-tenancy, such as a public cloud, which is a single instance of software that runs on a server that is accessible to multiple users is beneficial for centralised management. 

Finally, including rate limiting is a way to manage and protect the backend access through an API. Putting a limit on the number of API calls a user can make within a time period. 

When using Cyclr Connectors authentication, rate limiting, methods, multi-tenancy and data formats are all pre-built functions. Resulting in APIs built for integration. 

Testing your API

It is important to test the functionality of your API under different conditions in a testing environment. According to Codersera, “API testing consists of making requests to single or sometimes multiple API endpoints and validating the response for performance, security, functional correctness or status check”. They also note the different types of tests for an API.

  • Unit Testing: testing a single endpoint with a single request and response
  • Integration Testing: APIs are a central aspect of integration
  • End-to-End Testing: help with validating data between API connections
  • Performance Testing

API Testing is beneficial as you can gain early evaluation, and feedback of the overall APIs core functions. There are various API testing tools, popular options include Postman, and JMeter. Both can be used for functional API testing, an exploratory-type API testing. 

API Delivery

When you are ready to deploy your API, it is important to share the API description, and update the URL. Share or embed the API documentation with both internal users and external clients. Finally, publish the API to a developer portal to encourage adoption.

Monitoring your API

Keeping tabs of your API is useful to understand how it is being used, developed and improved. As well as if any issues arise that need to be addressed and iterated on. 

Cyclr’s Developers Best Practices for Developing APIs

What do our developers say about developing APIs? Here are some of their API building best practices.

  • Always include the real request/response information in the API documentation
  • Make sure the credentials or access to a test or live system are available 
  • Be sure to keep documentation up to date and accessible as well as a live service, like Sandbox
  • Create a consistent structure of endpoints and data structure
  • Clear, concise and interactive documentation with relevant walkthroughs and tutorials 
  • Include a standard submission of defined data 
  • If you are building an API for internal processes take a step back to see how it can evolve, how would an outsider view this service.
  • Be sure to communicate best practices of interacting with your API, such as rate limits and paging
  • An API that can filter or mine records 
  • Run tests on your API before launching
  • Build an API that is easy to read, use and is complete 

Sync with Cyclr’s API 

Did you know that we have our own Cyclr API? It is commonly used to deliver an advanced, user friendly, custom integration experience which sits behind your existing SaaS styling and UI. 

It is also extensible to act as a proxy for working with data in external SaaS applications in a uniform way. You can even drive Cyclr directly through a few API calls, so you can perform more advanced data processing before the data enters your application. 

We have a wide range of documentation and guides to help you get up and running.


Looking for more about working with APIs, read our developer interviews where we talk about the challenges of working with APIs, the dos and don’ts of API documentation, and working with different API authentication types.

Avatar for Hayley Brown

Hayley Brown

With several years experience in the digital marketing space after graduating from Sussex University, Hayley has gone on to work in the retail and education industries. In 2020 she joined the Cyclr team and is working alongside Daniel in the Marketing Department.