What is API integration?

An API is a set of rules or protocols that enable software applications to communicate with each other to exchange data, features and functionality. APIs can be used for simple integrations, such as enabling an e-commerce store to communicate with a payment system like PayPal, or enabling a blog to pull and embed posts from a social media website. 

In an enterprise system, APIs can be used to integrate larger, more substantial platforms, systems and workflows, such as enabling the real-time exchange of data between different enterprise databases or connecting independent applications to create automated business processes.

Traditional point-to-point integrations—connecting systems or applications directly through custom coding—require a substantial amount of setup work and upkeep. They are often not suitable for many modern environments that rely on hundreds or thousands of applications spread across distributed IT architectures.

API integration offers a more efficient solution. Through API integration, organizations can use APIs to expose integration flows and integrate applications, platforms and systems no matter where they reside—crucial in modern IT environments.

API integration underpins important integration tools such as integration platform as a service (iPaaS) solutions and plays a pivotal role in the modernization and digital transformation of enterprise IT architectures. Modernization requires a flexible approach that can support new and existing systems; API integration provides this approach by enabling organizations to modernize the interface to all enterprise systems.

Modernization doesn’t happen overnight. And while an organization works to modernize different parts of its IT landscape to drive innovation, it must be able to incorporate data, services and processes from both new and existing systems across the IT landscape. API integration enables the decoupling of the integration interface from the application itself, helping organizations innovate and remain agile without waiting for systems themselves to be fully modernized.

API integration and API management are distinct but complementary disciplines with different goals and approaches. Strong API management practices can facilitate API integration.

API integration concerns the use of APIs to expose integration flows and connect applications, business systems, processes and data.

API management is a broader set of practices and tools that approaches APIs as an asset class of its own and addresses the full lifecycle management of APIs. It is the scalable process of creating, publishing and managing APIs—sharing them, controlling access, tracking their usage and enforcing security policies—within an enterprise and multicloud setting.

Successful API management gives organizations greater control over their APIs. It strengthens and streamlines API documentation, API security and API discovery, helps organizations avoid infrastructure chaos and redundancy, and drives API efficiency. Overall, it helps create better APIs and a stronger enterprise understanding of what APIs exist and how they can be used, all of which aid API integration.

An efficient API management practice can help ensure that organizations are fully leveraging API integrations, and that components and data assets are reused when possible.  If there are existing APIs that can be used to invoke integrations, organizations can avoid the need to create custom APIs.

API integration helps organizations achieve several crucial outcomes:

The value of artificial intelligence (AI) tools rests heavily on the AI’s access to data. Data that is siloed in different departments across an organization or data that is outdated or inconsistent limits the potential of AI tools. The integration of data sources and business applications to create comprehensive data sets helps businesses fine-tune AI models and derive stronger AI insights.

Responsibility for innovation is moving beyond IT teams and software developers and line-of-business teams and citizen technologists are increasingly given greater independence and asked to drive innovation through integration tasks.

As teams with less specialization perform a greater number of integration tasks, the risk of sprawl, inefficiency and security or governance mishaps increases. API integration and iPaaS solutions help drive the democratization of data and enable non-IT personnel to perform integration tasks (through the help of low-code and no-code tools) while minimizing risk.

Many organizations have existing on-premises systems and processes (with troves of valuable data) at the foundation of their IT architecture that is not easily replaced. However, these systems were not built to interact with modern AI-based applications and automations. API integration helps organizations extend the life of traditional systems that would otherwise struggle in real-time architectures.

Rather than rely on ad hoc fixes that often add complexity and cost, API integration offers a solution that enables organizations to connect core systems and reliant business processes, with new technology.

API integration enables organizations to connect new services and applications with customer relationship management (CRM), enterprise resource planning (ERP) and other systems. These systems are often deployed in different environments with varied management systems and the success of all systems depends on the synchronization of data between them.

For example, an organization might have on-prem ERP and supply chain management (SCM) systems that need to exchange data with a software as a service (SaaS) CRM solution such as Salesforce and a customer support app hosted in the cloud. API integration helps bridge the gap between these different systems.

There are many ways that APIs are used to invoke integrations. Common examples include:

Organizations rely on API integration to streamline and automate their workflows across enterprise software systems. For example, organizations can use APIs to integrate business software that tracks inventory levels with software that tracks incoming orders to make essential data more visible to stakeholders.

APIs are commonly used to integrate CRM software with other enterprise systems such as ERP tools. API integration enables enterprises to sync these tools so that data can move between them, creating a single source of consistent, accurate data.

Organizations use APIs to integrate across various cloud computing and on-prem environments. Cloud service integrations enable data transfer across environments and geographies, helping organizations create more valuable workflows and break down data siloes.

Users encounter these sorts of integrations (often unknowingly) in both business and nonbusiness settings. Applications such as Slack use APIs to integrate other business software that employees use to collaborate into the platform.

For example, users can integrate a cloud-based file sharing program into the messaging app that enables file upload and sharing without leaving the application. With such integrations, employees don’t have to leave the messaging applications to work on other aspects of the business process.

APIs can be categorized by use case, including data APIs, operating system APIs, remote APIs and web APIs. Today, most APIs are web APIs.

Web APIs are a type of remote API (meaning that the API uses protocols to manipulate external resources) that expose an application's data and functionality over the internet by using Hypertext Transfer Protocol (HTTP).

Open APIs are open source application programming interfaces that users can access using the HTTP. Also known as public APIs, they have defined API endpoints and request and response formats.

Partner APIs connect strategic business partners. Typically, developers access these APIs in self-service mode through a public API developer portal. Still, they need to complete an onboarding process and get login credentials to access partner APIs.

Internal, or private, APIs remain hidden from external users. These private APIs aren't available for users outside of the company. Instead, organizations use them to improve productivity and communication across different internal development teams.

Composite APIs combine multiple data or service APIs. They enable programmers to access several endpoints in a single call. Composite APIs are useful in microservices architecture where running a single task might require information from several sources.

In programming parlance, a “protocol” is a system of rules that determine the parameters of how a particular program or application functions. Common API protocols, styles and languages include:

A REST API (also called a RESTful API or RESTful web API) is a type of web service API that conforms to the design principles of the representational state transfer (REST) architectural style. REST APIs are commonly used for integrations.

REST APIs use HTTP requests such as GET, PUT, HEAD and DELETE to interact with resources. REST makes data available as resources, with each resource represented by a unique URI. Clients request a resource by providing its URI.

REST APIs are stateless—they do not save client data between requests. It’s possible to build RESTful APIs with SOAP protocols, but practitioners usually view the two standards as competing specifications.

SOAP is a lightweight XML-based messaging protocol specification that enables endpoints to send and receive data through a range of communication protocols including SMTP (simple mail transfer protocol) and HTTP (hypertext transfer protocol.) SOAP is independent, which allows SOAP APIs to share information between apps or software components running in different environments or written in different languages.

Remote procedure call (RPC) is a protocol that provides the high-level communications paradigm used in the operating system. RPC presumes the existence of a low-level transport protocol, such as transmission control protocol/internet protocol (TCP/IP) or user datagram protocol (UDP), for carrying the message data between communicating programs.

RPC implements a logical client-to-server communications system designed specifically for the support of network applications. The RPC protocol enables users to work with remote procedures as if the procedures were local.

The XML-RPC protocol relies on a specific XML format to transfer data. XML-RPC is older than SOAP, but is simpler and relatively more lightweight in that it uses minimum bandwidth.

Like XML-RPC, JSON-RPC is a remote procedure call, that uses JSON (JavaScript Object Notation) instead of XML. JSON is a lightweight format for data exchange that is simple to parse and uses name-value pairs and ordered lists of values. Because JSON uses universal data structures, it can be used with any programming language.

gRPC is a high-performance, open source RPC framework initially developed by Google. gRPC uses the network protocol HTTP/2 and Protocol Buffers data format and is commonly used to connect services in a microservices architecture.

WebSocket APIs enable bidirectional communication between client and server. This type of API does not require a new connection to be established for each communication—once the connection is established it allows for continuous exchange. This makes Web Socket APIs ideal for real-time communication.

GraphQL is an open source query language and server-side runtime that specifies how clients should interact with APIs. GraphQL enables users to make API requests with just a few lines, rather than having to access complex endpoints with many parameters. This capability can make it easier to generate and respond to API queries, particularly more complex or specific requests that target multiple resources.

Organizations often use API integration platforms, sometimes called middleware, to manage integrations in increasingly distributed environments. iPaaS solutions are one such platform.

iPaaS platforms provide a unified interface where organizations can manage integrations. This centralized interface helps reduce chaos, promote integration and API efficiency, and democratize access in complex tech ecosystems, enabling a broader spectrum of users to execute integration tasks.

iPaaS platforms often use tools such as prebuilt connectors, templates and low- or no-code tools to reduce the need for custom coding. iPaaS and other integration platforms help reduce time-consuming operations efforts and errors and help simplify enterprise-wide integration.

Key features of integration platforms include:

The most successful API integration solutions support a wide range of integration patterns, including:

• Enabling data exchange and data integration between different applications, software systems and databases to ensure enterprise-wide data consistency
  
  
• Connecting disparate applications to automate multistep business processes
  
  
• Connecting multiple services into one through a shared interface (composite services)

Leading solutions connect applications and services, events (synchronous and asynchronous) and data sets across all use cases.

Abstraction via APIs is particularly important in modern architectures for two primary reasons:

• AI and other innovations have led to environments with more applications, with more endpoints and use cases and greater variability across systems.
  
  
• Organizations are undergoing modernization efforts and as the IT landscape evolves, the integration process must incorporate new and old systems at various stages of adaptation.

To do so, REST APIs are commonly used for synchronous exchange and Async APIs are used for asynchronous endpoints (such as Kafka Topics.) This approach creates an abstract layer to all integration points.

Modern architectures are complex and distributed and it is important that integrations are executed where they deliver the greatest performance and security value. API integration platforms support hybrid deployment models and enable integration wherever data resides.

API integration platforms can facilitate the execution of integration flows in vendor-managed SaaS, on-premises systems and in customer’s cloud accounts. And they provide the flexibility to adjust integration flows as systems are modernized.

Because more employees are responsible for integration tasks (such as creating composite services by using APIs) in modern enterprises, it’s important that integrations are accessible for a broad spectrum of users. The self-service and no-code tools that leading API integration platforms deliver help business technologists and other users to the right of traditional integrators connect their SaaS apps with other enterprise systems.

API integration helps organizations:

• Drive automation
• Extend life of traditional systems
• Improve scalability
• Derive value from AI
• Standardize data
• Improve user experience

API integration is used to connect systems, services and applications hosted in different environments. When these systems can exchange data automatically and in real time, it enables teams to create broader process automations that incorporate various applications and workflows, wherever they reside.

The abstraction offered by API integration enables organizations to incorporate core systems—and the valuable data within them—into modern workflows, without having to wait for the entire system to be modernized.

APIs are used to build modular architectures, where services can more easily be added or removed. Such architectures are more flexible than other models and enable organizations to add new features and services without having to make wholesale changes to the underlying architecture. APIs can also be reused across different applications.

An API-first architecture designed with flexibility in mind—using APIs designed with a standard format and without hardcoded dependencies, for example—can help make organizations more scalable and better positioned to respond to changing market trends or business initiatives.

For machine learning and other AI tools to be most effective they need access to lots of data. The more complete and current the data, the sharper and more valuable the insights the AI can produce. API integration helps organizations connect data from across the enterprise and enables organizations to derive the most value from the application of AI tools.

Without integration, data can end up siloed between different apps or business units, creating a complicated and often time-consuming experience for stakeholders who need access to this data. API integration is used to unify datasets and facilitate real-time data exchange between enterprise systems.