What Is an API Call?

Discover the power of API calls! Learn how these digital messages enable apps to communicate, automate processes and drive business integration.

An API call is a structured request sent from one software application to another to access data or functionality. In business integration, API calls enable different software systems, like CRM and ERP, to communicate and exchange information seamlessly, driving automation and efficiency.

Businesses rely on seamless communication between software applications to operate efficiently and innovate rapidly. Behind every interactive website component, every data exchange, and every integrated service lies a fundamental process: the API call. Understanding the meaning of an API call and how API calls work is important for businesses looking to leverage modern integration solutions such as the SEEBURGER BIS Platform with API Management and API Integration capabilities.

API calls are digital messages that are the backbone of modern API-led B2B integration, making it possible for businesses to access external data, automate processes, and connect diverse systems without sharing internal code. When an application needs to interact with another, it initiates an API call, which is essentially a specific request sent from one software application to another. Think of it as placing an order with a restaurant; you send a request (your order), and they fulfill it and send back a response (your food).

From fetching real-time stock prices to streaming videos or integrating customer relationship management (CRM) systems with enterprise resource planning (ERP) platforms, API calls are constant behind-the-scenes orchestrators. They are essential for achieving agility, accelerating innovation, and driving digital transformation.

For example, when an application broadcasts a live video on a social media platform, it sends a structured request, an API call, to that platform's servers. This request specifies the action to perform and includes necessary details like authentication tokens or parameters. The server processes this request, executes the task, and sends back a response, allowing the application to integrate features without direct access to the platform's internal codebase, ensuring API security and scalability.

The widespread adoption of APIs, especially when it comes to enhancing automotive processes through the integration of APIs, signifies their importance in modern software development. APIs simplify development by allowing developers to use existing technologies and data as building blocks, saving time and money. Firms utilizing APIs have reported increased market capital growth, underscoring their strategic value. This widespread use of API means that understanding what is an API call is more than just a technical concern, it’s a business imperative.

Understanding how API calls work is more than a technical requirement, it’s a key business capability. When an API call is sent, it doesn't just float into the digital ether; it goes to a predefined URL known as an API endpoint. This URL is specifically provided by the application or service you intend to interact with. The endpoint is hosted on a server owned by the service provider, such as Facebook's servers in the social media example.

Consider sending a physical letter: you need the correct address (the endpoint URL) for your message to be successfully delivered. Similarly, an API endpoint serves as the digital address where your API call is directed. These endpoints are often structured to represent particular resources or actions. For instance, a weather API might have an endpoint like api.weather.com/current-weather to retrieve current weather data.

For web APIs, the URL typically includes the application layer protocol, such as HTTP, used to reach it. Most web APIs utilize HTTP, meaning their endpoints will start with http:// or https://. This precise addressing ensures that your API call reaches the correct destination, allowing the server to process the request, execute the action, and send back the appropriate response.

An API call is a sophisticated message comprising several essential components that dictate its purpose and how it should be handled. Every API call includes the following components:

Endpoint	As discussed, this is the URL where the API is hosted, specifying where the request is sent. A common API call example endpoint might look like "https://api.hubapi.com". Many APIs have different endpoints, each with its own path for specific functionalities. For instance, an API might have a base path like "https://api.example.com" and then specific endpoints like /users or /products.
HTTP Method	This component specifies the type of action you want to perform on the resource at the endpoint. These methods align with CRUD (Create, Read, Update, Delete) operations and provide API standardization for enhanced automotive security and industry progress. GET: Used to retrieve or get data from a server. If you want to see a list of items, you'd use a GET request. POST: Used to create new data or post new resources to the server. PUT: Used to update existing data or put changes to a resource. DELETE: Used to remove data or delete a resource from the server.
Header	Headers provide context for the server, telling it how to handle the request and what to expect in return. They don't contain actual data but are crucial for proper communication. Common headers include: Authorization: Contains credentials (e.g., Bearer ) to authenticate the request. Content-Type: Specifies the format of the data being sent in the request body (e.g., application/json). Accept: Defines the desired format of the response you want to receive (e.g., application/xml).
Parameter	Parameters are data sent to refine or filter the request, customizing what data to retrieve or how to process it. There are two main types: Path Parameters: Embedded directly within the endpoint URL (e.g., /users/123 to retrieve a specific user). Query Parameters: Added after a ? in the URL and separated by & (e.g., ?category=books&limit=10 to filter a list of books).
Request Body	This is the payload containing the actual data to be created or updated on the server, typically in JSON or XML format. It is sent with HTTP methods like POST or PUT. An API call example request body for creating a user might look like: { "name": "john", "email": "john@example.com", "role": "user" }

These components work in concert to form a complete API call, directing the request, specifying the action, providing necessary context, and delivering any required data.

Executing an API call involves a series of steps to ensure the request is properly formulated, authenticated, and understood by the target API. While the exact implementation may vary depending on the programming language or tool, the underlying process remains consistent.

	Identify the API endpoint URL The very first step is to know the Uniform Resource Locator (URL) of the external server or program you want to interact with. This is the digital "address" for your request. API documentation is your primary resource for finding the base URL and specific endpoint paths for each action. For example, the base path for a service might be api.example.com, with a specific endpoint for user profiles as /user-profiles.
	Choose the appropriate HTTP method Once you have the URL, you need to specify the type of action you wish to perform using an HTTP method. As discussed, common methods include GET (to retrieve), POST (to create), PUT (to update), and DELETE (to remove). Your choice depends on your intended operation. For instance, to retrieve a list of alternative fuel stations, you would use a GET request.
	Include necessary headers and parameters Headers provide important context about your request and the expected response. Common headers include Content-Type to specify the data format of your request, and Accept to indicate the preferred response format. Parameters, whether path or query, refine your request by filtering or providing specific data points. API documentation will detail which headers and parameters are required for each endpoint.
	Authenticate your request Most APIs require authentication to ensure that only authorized users or applications can call API. This often involves an API key or an access token. These unique identifiers authenticate calls, grant or deny access based on permissions, and sometimes track request usage. You typically obtain these credentials from the API provider's developer page and include them in your request, often as an Authorization header or a query parameter.
	Send the request and handle the response When the API call is properly constructed, you can send the request. The API server processes it based on the endpoint, method and data provided, executing the intended action. After processing, the server generates an HTTP response, which includes a status code and often a response body.

While API calls are indispensable for modern communication and data exchange, they also represent potential entry points for security vulnerabilities if not properly secured. Exploited API calls can lead to significant data breaches, system compromises and performance degradation, costing businesses substantial financial losses.

In order to protect your APIs and secure your digital future, consider the following 10 security measures:

1. Strong authentication and authorization

Implement robust mechanisms like API keys, OAuth 2.0, or JSON Web Tokens (JWT) to verify user identity and enforce granular access controls (RBAC), ensuring users only access authorized resources. Tokens should have expiration times to limit their misuse.

6. HTTPS (SSL/TLS) encryption

Always use HTTPS to encrypt and protect confidential data during transmission, safeguarding against eavesdropping and ensuring secure communication between applications.

2. Prevent API key leaks

Educate users on best practices for handling API keys and implement regular key rotation to minimize common API security risks.

7. Logging and monitoring

Implement comprehensive logging of API calls and responses, alongside continuous monitoring for suspicious activity and unauthorized access, enabling rapid detection and response to security incidents.

3. Input validation and sanitization

Thoroughly validate and sanitize all incoming data to prevent injection attacks and ensure only expected values are processed.

8. API gateway

Utilize API gateway security for centralized management of API security, in order to provide a single point for enforcing policies, authentication, authorization and monitoring across all APIs.

4. Rate limiting and DDoS mitigation

Implement rate limits to restrict the number of API calls a client can make within a period, and deploy Web Application Firewalls (WAFs) to block malicious traffic and protect against DoS attacks.

9. Regular security audits and penetration testing

Proactively identify and address vulnerabilities through consistent security audits and penetration testing.

5. Injection attacks

APIs that fail to validate user input are vulnerable to malicious code injections (like SQL or XSS), allowing attackers to extract, modify, or corrupt data.

10. API versioning

Implement API versioning to ensure backward compatibility and facilitate the secure deprecation and retirement of older, potentially vulnerable API versions.

What is the most common example of an API call?

A common API call is when you check flight availability on a travel website. Your search triggers an API call to various airline databases, which then return real-time information about flights and prices.

How do API calls work to ensure data security?

API calls are secured through various mechanisms, including authentication (e.g., API keys, OAuth tokens) to verify legitimate users, input validation to prevent injection attacks, HTTPS encryption for data in transit, and rate limiting to defend against DoS attacks.

Why is API management important for API calls?

API management provides visibility and control over all API calls within an organization. It ensures APIs are designed for maximum efficiency, adhere to high security standards, and support scalability for future digital transformation, preventing data breaches and performance issues.

SEEBURGER understands that in a world that’s driven by API-first architecture, you need seamless connectivity. The BIS Platform supports various API types, including REST API calls and SOAP APIs, ensuring flexibility for diverse integration needs. BIS is designed to simplify this complexity, offering comprehensive API management capabilities that support both IT and business teams.

The BIS Platform empowers businesses and IT teams with API Management and API Integration to manage, secure and optimize API calls as part of an overall integration strategy that provides cloud integration services for API.