What is API-first Approach? - Uncovering Key Details!

API-first approach is a development methodology prevalent in the development circle today. Here, we have shared the key details to get you started.

If an application is a human body, then API or Application Programming Interface is the organ. An API is a necessary part that developers integrate, and users interact with to access different functionalities. So much so that developers and companies began to prioritize API development, giving way to an API-first approach.

Today, with this article, we will be taking a deep dive to truly understand what is API-first and other relevant information to get you started with the methodology. So, let’s begin!

What is API-First Approach?

API-first is often misconstrued as a technology; however, it is more of a philosophy for development. So, it is important to understand it from a historical perspective, actual definition, and philosophical counterpart to truly instill it within your development process.

History

The roots of API-first development go back to the early days of the Internet. Back then, only developers understood the need to create reusable components that could integrate with different applications on command.

However, several key milestones gave way to the future of API-first, from which we benefit today:

• Early 1990s: The emergence of WWW (World Wide Web) and HTTP (Hypertext Transfer Protocol) led to the development of early web APIs, also known as Simple Object Access Protocol (SOAP).
• Late 1990s: The rise of companies like Amazon and eBay spurred the creation of much more sophisticated APIs for online services.
• Early 2000s: Introduction of RESTful APIs by Roy Thomas Fielding, which can be accessed online using HTTP methods for different actions. It gained much more popularity and became a standard practice.
• Mid-2010s: The term “API-first” started getting used frequently, and companies started prioritizing the development of APIs first before the front-end or back-end components of an application.
• 2010s and 2020s: Continued growth of the API economy through companies like Twilio, Stripe, and SendGrid that developed APIs for a wide range of services and offered them to developers to create their own apps.

Defining API-First 

The API-first approach wasn’t defined by a single entity. Instead, it became a way to describe this development philosophy. So, there is no single authority from which the term came. Contrarily, it became a part of the lingo throughout the development community over time. So, as per the general consensus available online, below we have tried to define API-first, as per our own understanding:

“API-first is a software development approach where the design and development of API comes first before creating a UI or component of an application.”

Foundational Philosophy

The concept of API-first design and API-first development gave way to this innovative approach that creates APIs as standalone products and not as complements or appendices to other applications. 

The first and foremost priority is to establish a comprehensive system of microservices or loosely coupled APIs with high internal connectivity as an API landscape.

Like with the API Economy, where you inculcate business practices and create models to ease the use of APIs to increase the business success rate. Similarly, API-first means that the methodology is promising a new revenue generation strategy by building products using these APIs. It also fosters the philosophy of preferring open and pluggable APIs rather than rigid ones that are focused on a singular objective. 

Consequently, APIs have evolved from being simple integration solutions and started being viewed as valuable company resources that engender business outcomes.

Principles of API-First Approach

API-first, as an approach, follows a variety of principles that are approved by a larger consensus but haven’t been clearly defined by any higher authority or regulatory body. 

So, it is impossible to provide principles that take a common form everywhere. However, below, we have tried to consolidate several principles that can elevate the integration of API-first within your development cycle. 

1. Clearly articulate the purpose of the API from a business point of view.
2. Determine the target audience of the API, as per specific requirements.
3. Establish a clear API design, documentation, and even versioning to ensure consistency.
4. Adhere to the principles of RESTful architecture.
5. Keep a versioning strategy in place to make changes with ease.
6. Use tools like Swagger to define and document the APIs clearly.
7. Provide tools that enable developers to test and experiment with APIs.
8. Search for a scalable infrastructure that can handle increasing traffic through the API.
9. Implement a caching strategy that ensures improved response times.
10. Establish rules and policies that help ease the development and management of APIs.

Emergence and Industry Adoption

The concept of creating APIs goes back to the early 1990s, as discussed above. However, the prominence that the API-first approach gained can be attributed to several reasons:

• Rise of microservices
• Increasing demand for interoperability
• High demand for reusable features
• Recognition of the benefits of creating decoupled applications

So, businesses began to involve the design and development of APIs as a foundation for a projection. This, in fact, simplified software development, giving way to more modularity, reusability, and scalability within projects.

When such principles formed the foundation of organizations, the oversight of the organization to form practicable API development methods resulted in API-first, organically.
Experts and surveys do not define ‘API-first,’ although many companies and developers have discussed its meaning. 

In fact, several reports released by companies like Gartner, Imperva, and F5. in 2024 paint a clear picture that showcases the significance of API-first development strategy:

• The number of API endpoints used by a single account averages out to 613.
• Around 71% of all the web traffic is related to API.
• Around 82% of respondents say that their company uses APIs.
• 71% of respondents say that they have used third-party APIs from SaaS vendors.
• The number of APIs is expected to grow by a minimum of 10% by the next two years.

API-first Approach Benefits

Leveraging an API-first design scales up the inherent benefits of APIs, letting organizations be more innovative. This allows organizations to deliver more often, make fewer mistakes, and bounce back quickly in case of failure. This is further backed by Google’s Digital Transformation Report, which credits ‘API-first approaches’ empowering organizations with greater advancement rates and increased business partnership value through API exchange.

In fact, there are several API-first transformation benefits that surpass the benefits discussed above and are essential to understanding the full capability of the API-first architecture. 

Enhanced Developer Experience

In the case of API first, APIs are core components since they constitute pre-subscription functionalities that developers can leverage to avoid developing complex structural systems from scratch. 

The above approach fosters better API, which makes the developers’ experience even better. Synchronization of data format, protocol, and processes to use is another plus of ‘API-first’ since it minimizes interface barriers for developers and users of the traditional as well as AI API platforms. 

Unmatched Flexibility

The most effective component of an API-first approach is the fact that even though two APIs don’t share a similar technology stack, they can still be used together to create an application. In fact, API-first for developers uses a variety of architectures like GraphQL, SOAP, gRPC, RPC, etc. However, the majority of APIs that are built from an API-first prospect use REST.

This enables APIs to facilitate the use of microservices, enabling developers to scale and manage APIs better. This is achieved through the use of containers and other virtualization technologies. With this, it is possible to break down an application into small, independent services. This helps improve the scalability and flexibility of an application for better development efficiency in the future.

Seamless Interoperability

APIs that are developed using API-first also have to follow standard practices, and one of the most popular standards is the OpenAPI Specification (OAS). This standard allows for the usage of a common language that ensures API providers and consumers have a clear understanding of the API structure, endpoints, operations, and data models. Also, it is important to know that it is machine-readable so the platforms and tools are automatically able to interpret the definition of API.

So, in return, API providers and consumers get to benefit from an accumulation of complementary tools and systems that create a strong synergy the more they are used within the ecosystem. With OAS, there is the elimination of duplicate work, improved cooperation, testing, documentation, and the creation of client SDKs (Standard Development Kits).

Driving Innovation and New Opportunities

APIs provide additional value that remains concealed in old systems and allow organizations to generate fresh revenue sources. To that end, the API-first platform follows the principles of documentation, consistency, and reusability. This helps cover a variety of business cases and engages different stakeholders. For instance, internal departments, business partners, and third-party contractors. 

This kind of modular foundation is also good for omnichannel initiatives, which systems can use through API access.

Challenges of the API-First Approach

While we know that API-first strategy offers many advantages, it also comes with several challenges that you need to address:

• Cultural Shift: API first means switching the approach to product-level API management, which requires backing from the leaders. Thus, many compelling arguments point to the need for executives to take charge of the matter to achieve the envisioned changes to processes, personnel, and culture.
• Technology Diversity: Each API has the option of deciding on a technology stack for the implementation. In fact, some organizations will necessarily have technology heterogeneity in their sets of APIs. They can reduce workforce flexibility, extend the development time, and have an influence on the final quality.
• Increased Security Risks: APIs need to be accessed over networks, and the use of multiple APIs adds risk since this increases the number of prospects that can be attacked.
• Governance: Technology diversity, security, compliance, and the enforcement of policies across the API need effective governance. These strategies include proper release processes, versioning, and compatibility of one version with another.

Steps to Adopt an API-First Strategy

Adopting an API-first approach requires an understanding of the API-first principles if you are willing to devise your strategy from scratch. However, if you are looking to embrace API-first, you can also follow a structured process, as outlined in Tyk’s white paper, "Approaching Your API Strategy", which goes as follows:

Also Read: API Development Guide - Terminologies, Development Process, Best Practices, etc.

1. Define Your Strategy

Before beginning the development of an API, it is important to ensure its purpose. For example:

• Connection of disparate systems like CMS, marketing automation platforms, etc.
• Automation of the workflow to reduce manual labor.
• Integration of third-party services to expand capabilities.
• Creation of an ecosystem ensuring complementary services.
• Facilitating data exchange between internal and external systems, etc.

There are many other reasons to come up with an API strategy, but we’re sure you get the point. Also, make sure the executive level has clear objectives and shares those objectives frequently so every team is aware of the program's goals and target audience.

2. Create Organizational Alignment

Developing an API is not a standalone task. Instead, it is a digital asset that evolves over time. So, choose a product-oriented delivery method, advance cross-functional team ownership, and deliver training that equips teams to work autonomously.

3. Manage Your API Program

Developing an API program is essential for the implementation of the API-first approach. However, for that, you need to establish an effective governance. This would ensure that the relevant team members are experienced enough to meet the requirements.

Further on, it is important to set up clear API standards, protocols, and design patterns. This would help control APIs on a much more granular level, ensuring the success of the product as per market requirements and high-quality service.

4. Focus on API Adoption

Establish that the user experience for API discovery and onboarding is straightforward because an API without any users is of no value. To ensure that, you can check certain things:

• Clear documentation can make it easy for developers to understand and use the API you developed.
• An excellent support system can help developers integrate API with ease.
• Deliverance of relevant SDKs and sample codes can simplify the integration process.
• Create a portal to develop a community so that the necessary queries are sorted amongst developers.

5. Accelerate Your API Program

Bring teams in architecture, security, engineering, and program management together to realize a product-driven approach that lowers barriers and accelerates development.

Alternatives to API-First

While API-first is highly regarded, there are other approaches that are often adopted by developers, such as:

• Backend-first: Here, backend components are built and tested before the frontend or the APIs. This strategy values API integration. However, the backend-first approach often leads to tightly coupled components or over-engineered APIs. 
• API Design-first: One variation of API-first is this method, aiming to design clear and structured APIs along with documentation and style guides. This approach takes more effort initially, but it generates APIs that are more dependable and capable of change, provided there’s greater strategic insight into API-first.
• Code-first (Integration-first): APIs are utilized as tactical mechanisms targeted for certain application requirements within a single project. The fastness of implementation of this method constrains the flexibility and the long-term value of APIs.

Embracing the API-First Mindset

For businesses looking to prioritize APIs within their approach, API-first is the obvious option. 

The approach is inclusive, even going further than design, development, and creating API platforms that build the foundations for multiple consumers. However,  effective governance maintains that the API program operates efficaciously, conforms to business goals, and reacts to user requirements.

While there may be greater initial and ongoing expenses with API-first, the benefits – which include better developer experience, technical flexibility, system interoperability, and innovation - make it an enticing option for organizations that are committed to a design-led approach or even that have a large API footprint.

Real-World API-First Examples - Understanding Impact!

With the kind of convenience API-first strategy offers, plenty of companies have adopted it in the past. To help understand from a real-world perspective, below, we have mentioned some companies that provided APIs for other services to use, promoting API-first.

Tomorrow.io

Tomorrow.io is a leading weather intelligence provider that illustrates a great example of an API-first approach through its weather API. Through this API, it gives access to real-time weather information around the globe. 

Developer Experience

The platform from Tomorrow.io provides a posture that developers love, with clear documentation, code samples, and interactivity via Swagger UI. By industry standards, their APIs provide consistency and compatibility across all platforms.

Flexibility and Scalability

Tomorrow.io has managed to establish an API system that is both flexible and scalable, thanks to API-first. Each API is considered a distinct product, which permits individual updates and enhancements, assuring the platform stays ahead of the curve.

Innovation and Partnerships

Tomorrow.io has encouraged partnerships across industries, such as logistics and agriculture, by making its APIs accessible and easy to use. This has resulted in both innovation and the development of new revenue streams.

Netflix

Netflix is a great example of an API-first approach. Its API is used by a wide range of services, applications, and devices like smart TVs, gaming consoles, streaming devices (Roku, Amazon Fire TV), etc. In fact, social media platforms like Facebook and Twitter have also integrated Netflix’s API.

Developer Experience

Netflix’s API provided developers with a well-documented and easy-to-use platform. This helped Netflix deliver a consistent design pattern, reducing the learning curve and providing a secure authentication mechanism.

This API also provides code samples and SDKs for a variety of programming languages to make the integration easy. Also, the API delivers a high level of flexibility, customizing integrations to meet specific requirements.

Flexibility and Scalability

Netflix API allows developers to integrate other applications and services, helping them create a tailored experience. Plus, the application is capable of handling large volumes of traffic, ensuring scalability at demand.

Innovation and Partnerships

While Netflix’s API delivers clear documentation, making it accessible to a wide range of developers, it also encourages them to create a much more diverse ecosystem through third-party integration. This has even led to new features like social viewing and personalized recommendations. Plus, the API’s bundled services to customers expand its reach.

GitHub

GitHub is a very popular online repository hosting service. The platform helps developers collaborate on code projects, track changes, and even manage versions. The service offers a powerful API that allows developers to interact with repositories through programs, giving way to an API-first approach. 

Developer Experience

The API of GitHub allows developers to automate tasks, integrate them with other tools, and customize the workflow. The API can be used to manage collaborators and team members, thereby improving team play. Also, it delivers a consistent yet predictable way of interacting with repositories of the platform.

Flexibility and Scalability

The core nature of GitHub allows the platform to promote flexibility and scalability. It delivers a way to store code repositories and is used on the go by developers. This allows associated team members to check relevant repositories and make changes for a plethora of functionalities. Also, the developers can start building over the repositories, ensuring scalability to accommodate more people for an application.

Innovation and Partnerships

GitHub is primarily meant for developers to collaborate, encouraging them to experiment and create. The collaboration lowers the entry barrier for developers and helps them create a diverse ecosystem that provides unique value. 

It can also be used to create new features together and enables partnerships with cloud services, project management tools, and CI/CD pipelines. 

Conclusion

An API-first approach or methodology marks a change in the software development process, valuing APIs as standalone products and necessary elements for fostering innovation. Although it is hard, the benefits – such as greater flexibility, better developer experiences, and potential for new business possibilities – make it a persuasive method for modern organizations.