API First Development

by Mansa HR

Posted on 02/22/24 6:19 AM

In today’s fast-paced digital world, API First Development has come up as a revolutionary approach to software development. This method gives importance to the design and development of Application Programming Interfaces (APIs) before any other aspect of the application. With this the API First Development ensures that the API serves as the foundation for the entire software project enabling seamless integration, scalability, and flexibility. Let us go deeper into this innovative approach and explore the latest trends.

What is API First Development? API First Approach.

API First Development is a software development approach where the project starts with defining and designing the application programming interface (API). In this method, the development team first designs and documents the API that will be used for communication between different software components, before starting to implement the business logic or user interface.

The API First Approach involves designing the API contract first, before writing any code. This means defining the endpoints, data formats and communication protocols that will be used by the API. By establishing a clear and comprehensive API contract developers can ensure that all subsequent development work aligns with the intended functionality and data requirements.

Core principles of API First development

The core principles of API First development revolve around the idea of giving importance to  API design and development as the initial step in the software development process. Some of the key principles include:

  • Design-First Approach: Emphasizing the design of APIs before writing any code.
  • Clear API Contracts: Creating well-defined API contracts that outline the expected behavior and data formats.
  • Modularity and Reusability: Designing APIs with a focus on modularity and reusability to promote scalability and flexibility.
  • Collaboration: Encouraging collaboration between cross-functional teams including developers, designers, and stakeholders, to ensure that the API design meets the needs of all stakeholders.

Importance of API First Development

API First Development offers several benefits that make it a crucial aspect of modern software development:

  • Enhanced Flexibility: By designing APIs first, developers can ensure that the application architecture is flexible and adaptable to future changes.
  • Improved Collaboration: API First Development fosters collaboration between different teams involved in the software development process leading to better alignment of goals and requirements.
  • Faster Development Cycles: With a well defined API contract in place, developers can work in parallel leading to faster development cycles.
  • Easier Integration: Well designed APIs make it easier to integrate with third-party services and platforms enhancing the overall functionality of the application.

How to implement an API First Approach

Implementing an API First Approach involves following a structured process to design and develop APIs. The following steps can guide the implementation of an API First Approach:

  1. Identify Use Cases: Begin by identifying the use cases and functionality that the API needs to support.
  2. Design API Contract: Create a clear and comprehensive API contract that outlines the endpoints, data formats, and communication protocols.
  3. Mocking and Testing: Develop mock APIs based on the API contract to test the functionality and gather feedback.
  4. Iterative Development: Iterate on the API design based on feedback and testing results, ensuring that it meets the requirements.
  5. Implementation in Application: Once the API design is finalized, implement it in the application and continue with the development process.

OpenAPI Specifications and Why are they used?

OpenAPI Specifications, formerly known as Swagger, are a widely adopted standard for defining RESTful APIs. They provide a way to describe the structure of an API, including its endpoints, request/response formats, authentication methods, and more. OpenAPI Specifications are used for several reasons:

  • Standardization: OpenAPI Specifications provide a standardized way to document and define RESTful APIs making it easier for developers to understand and use them.
  • Code Generation: They can be used to generate client libraries, server stubs, and API documentation automatically, saving time and effort in development.
  • Tooling Support: Many development tools and frameworks support OpenAPI Specifications enabling seamless integration with various development environments.

Difference between API First and API Enabled

The main difference between API First and API Enabled approaches lies in their priorities and focus:

  • API First: In API First approach, the primary focus is on designing and developing APIs as the foundational element of software development.
  • API Enabled: On the other hand, API Enabled approach focuses on building an application first and then exposing its functionalities through APIs as an additional feature.

Advantages and Disadvantages of API First Development


  • Better Alignment with Business Goals: API First Development ensures that the APIs are aligned with the business requirements from the outset.
  • Improved Developer Experience: Well-designed APIs make it easier for developers to understand and use them, leading to a better developer experience.
  • Enhanced Flexibility: APIs designed with an API First approach are more flexible and adaptable to changes in requirements or technology.


Upfront Investment: Designing APIs first requires upfront investment in planning and design, which may seem time-consuming initially.

Complexity: Managing a large number of APIs can introduce complexity in terms of maintenance and governance.

In conclusion, API First Development is a forward-thinking approach that prioritizes the design and development of robust APIs as the foundation of software applications. By embracing this approach, businesses can benefit from enhanced flexibility, improved collaboration, and faster development cycles. OpenAPI Specifications play a crucial role in defining and documenting APIs, while the API First approach offers distinct advantages in terms of alignment with business goals and developer experience..

At Mansa Infotech, we are committed to helping our clients achieve their API First Development goals through the use of best practices and industry standards. If you’re interested in learning more about our API First Development services, please feel free to contact us. We would be happy to discuss how we can help you improve your API First Development process and achieve your business objectives.

FAQs on API First Development


  • What is API First Development?


API First Development is a software development approach that prioritizes the design and development of Application Programming Interfaces (APIs) before any other aspects of the application.


  • What are the benefits of using API First Approach?


Some of the benefits of using an API First Approach include enhanced flexibility, improved collaboration, faster development cycles, and easier integration with third-party services and platforms.


  • What are the limitations of API First Development?


Limitations of API First Development include upfront investment in planning and design, as well as potential complexity in managing a large number of APIs.


  • How to implement an API First Approach?


Implementing an API First Approach involves identifying use cases, designing the API contract, mocking and testing, iterative development based on feedback, and implementing the finalized API design in the application.


  • What is the relation between API First and Microservices?


API First Development aligns well with the principles of microservices architecture as it emphasizes the creation of well-defined APIs that can be independently developed, deployed and scaled to support microservices-based applications.