What is an API? An application programming interface (API) is a set of rules and protocols that allows software systems to exchange data or share functionality. The API defines how requests are made, processed, and delivered, allowing applications to communicate and integrate capabilities effectively. Demo Auto Engine
Things to know about APIs
How do APIs work? What are API integrations? What are the different types of APIs? What are API endpoints? What are the benefits of APIs? Optimize automation with API ServiceNow
This first computational machines developed in the mid-20th century were strictly stand-alone devices—they operated independently, with no means to share data or resources, limiting their functionality to isolated tasks. But as digital capabilities evolved and computers became more powerful and widespread, the need for systems to communicate and exchange information became clear. This demand gave rise to the concept of APIs—mechanisms designed to provide a structured way for software systems to interact. 

API stands for application programming interface and describes sets of rules and protocols that allow software applications to integrate data and coordinate their functionality. By serving as a bridge between systems, APIs make it possible for different programs to work together, increasing their effectiveness, capability, and processing power well beyond what each individual machine could manage on its own.  
Expand All Collapse All How do APIs work?
In API interactions, the application making the request is called the ‘client,’ while the application providing the response is the ‘server.’ For example, when a user opens a navigation app to retrieve real-time traffic updates, the app takes the role of the client, as it is requesting data from the server (in this case, a traffic monitoring system). 

APIs use specific protocols and architectures to manage these interactions. When a request is made, it travels from the client application to the API endpoint, often using a uniform resource identifier (URI), which specifies the requested resource. The server processes the request and sends a response back to the client, completing the transaction.  

Depending on varied factors, there are four primary ways that APIs can operate: 

SOAP APIs
These APIs use the simple object access protocol (SOAP) to exchange data in XML format. While reliable and secure, they are less flexible and more complex than some of the more modern alternatives. SOAP APIs are often used in enterprise systems, such as financial services, where strict standards and error handling are top priorities. 

RPC APIs
Remote procedure call (RPC) APIs allow the client to execute a function on the server, which processes the request and returns the result. These APIs are efficient for tasks like initiating computations or running predefined operations. For example, a server-side analytics program might use an RPC API to calculate and send detailed reports back to a client. 

WebSocket APIs
These APIs support two-way, real-time communication between the client and server using JSON objects. They are especially effective for scenarios requiring constant updates, such as chat applications or live tracking, where servers can push data to clients without waiting for a request. 

REST APIs
Representational state transfer (REST) APIs are the most widely used today, employing HTTP methods like GET, POST, PUT, and DELETE to manage data exchanges. REST APIs are ‘stateless,’ meaning each request is processed independently, making them scalable and ideal for web services like online marketplaces or content-sharing platforms. 
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What are API integrations?

API integrations connect two or more software systems, enabling the automated exchange of data and functionality through their application programming interfaces (APIs). These integrations are what make automation possible for tasks ranging from syncing cloud storage to enabling dynamic updates. For example, when a customer relationship management (CRM) or customer service management (CSM) system updates sales data in real time across multiple platforms, it is being accomplished through API integrations. 

API integrations involve two key components: 

  • Spokes
      Spokes are the endpoints or systems that an API connects to, such as a cloud service, database, or application.  
  • Actions
      Actions define what the API does within the integration—such as retrieving, updating, or deleting data.

For instance, in an eCommerce integration, the API may connect to a payment gateway (spoke) to process a transaction (action). Some vendors, such as ServiceNow, simplify API integration by enabling the creation of custom spokes using generative AI (GenAI). This makes it possible for businesses to rapidly build tailored workflows without extensive coding expertise. 

What are the different types of APIs?
APIs are categorized based on their architecture and scope of use, providing flexibility to meet various operational needs. While architectural classifications like REST, SOAP, and others determine how APIs function, scope-based classifications focus on who can access the API and how it is used. Below are the primary types of APIs, classified by scope:

Private APIs
Private APIs, also known as ‘internal’ APIs, are restricted for use within an organization. These APIs are not exposed to external users or developers and are designed to enhance internal workflows, integrate systems, and improve productivity. For example, a company might use a private API to sync data between its HR management software and payroll systems, promoting consistency across internal processes. 

Public APIs
Public APIs (or ‘open’ APIs) are accessible to citizen developers and the rest of the general public. These APIs often require authorization but are designed to extend the functionality of an application to a broader audience. For instance, a public API might allow third-party apps to integrate with a social media platform for features like posting content or retrieving analytics. Public APIs often serve as a tool for companies to increase their platform’s adoption and foster innovation. 

Partner APIs
Partner APIs are made available to specific external developers, usually as part of a business-to-business (B2B) collaboration. These APIs help facilitate partnerships by enabling secure access to systems or data. For example, a payment processing company could provide a partner API to an e-commerce platform to help optimize payment services. Access to partner APIs typically involves an onboarding process, including authentication and authorization. 

Composite APIs
Composite APIs combine multiple APIs to perform complex operations or retrieve data from multiple sources in a single call. These are particularly useful in microservices architectures, where a single action—such as processing an order—requires input from inventory, shipping, billing, or other systems. 
What are API endpoints?
API endpoints are specific touchpoints within an API where requests are sent and responses are received. They represent the URLs or digital locations that enable communication between a client and a server, serving as the gateway for data exchange. Endpoints make it possible for users to access specific features or data from another system without having to build those functionalities from scratch.  

However, API endpoints are major considerations in system performance and security. Because endpoints handle data exchange, they are potential vulnerabilities for cyberattacks. Monitoring and securing endpoints is necessary to prevent unauthorized access and misuse. High-traffic endpoints can likewise create bottlenecks, slowing down response times and affecting user experiences. 
What are the benefits of APIs?

APIs are a cornerstone of modern application development and business operations, providing a powerful opportunity to improve system communication and functionality. More specifically, APIs make possible the following advantages: 

  • Improved collaboration
    APIs integrate disconnected platforms and applications, creating essential connections that allow them to work together. This connectivity makes it possible for organizations to automate workflows and eliminate information silos. 

  • Accelerated innovation
    By abstracting complexity and offering reusable components, APIs support developers in creating new applications faster and more efficiently. Businesses can use APIs to connect with partners, expand into new markets, or introduce innovative services. 

  • Data monetization
    Organizations can monetize APIs by offering premium access to valuable data or functionality. This practice, known as the API economy, allows businesses to generate revenue while fostering developer communities. 

  • Enhanced system security
    APIs provide layers of security by separating requesting applications from the underlying infrastructure— including IT infrastructure, cloud-computing infrastructure, AI infrastructure, and network infrastructure. Features like authentication credentials, API gateways, and encrypted communication help protect systems from unauthorized access and cyberattacks. Proper API management ensures these security measures are consistently applied across all endpoints. 

  • User security and privacy
    APIs allow organizations to enforce strict access controls, ensuring that only authorized users and applications can interact with sensitive information. This layered approach reduces the risk of cybersecurity breaches while supporting compliance with data-privacy standards. 

  • Business agility
    APIs provide a simple interface for developers and external partners. This flexibility enables organizations to rapidly adapt to changing business needs, integrate with third-party systems, and support modular application development.

The role of API management
Effective API management is crucial to realizing the benefits listed above. API management provides the tools and practices for designing, deploying, and monitoring APIs to ensure optimal performance and enhanced security. By implementing a comprehensive approach to API management, organizations can maximize the value of their APIs while maintaining high standards of compliance and usability. 

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Optimize automation with API ServiceNow
APIs have transformed the way organizations build, integrate, and scale their technology systems, enabling seamless communication and automation across platforms — but modern digital transformation demands more than individual integrations. As AI takes on more complex responsibilities, businesses need real-time access to the right data, governed end-to-end, and delivered through a platform that understands context. ServiceNow Workflow Data Fabric meets this need by bringing together structured, unstructured, and streaming data from across the enterprise to create a solid, AI-ready foundation. 

Workflow Data Fabric is built on the ServiceNow ServiceNow AI Platform, offering a comprehensive suite of solutions to meet modern API needs—from integration and automation to centralized API management. Teams can enhance visibility into data and apps, simplify how they manage and monitor APIs, and unlock faster performance at scale. Paired with Boomi API Management and other integrated solutions, Workflow Data Fabric gives organizations the ability to act on data instantly fueling smarter automation and turning disconnected workflows into coordinated business outcomes. 

Demo ServiceNow today, and see how Workflow Data Fabric can enhance your approach to APIs.
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