What Is an API Endpoint?

APIs and API endpoints play a pivotal role in the development, integration, and launch of software products with remarkable speed and efficiency. In this brief read, we'll introduce API endpoints and discuss how they work.

How do APIs work?

An API, or Application Programming Interface, acts as a set of guidelines defined by developers to enable communication between different applications. Think of an API as a mediator that translates requests from one application into understandable instructions for another.

If it weren’t for APIs, disjoint systems like CMSs, databases, cloud services, etc. would remain siloed; unable to communicate or share data with each other.

What exactly is an API endpoint?

An API endpoint is a location where an API can be accessed to invoke a particular functionality. APIs can expose many endpoints, each representing the API's distinct operation or service. 

Exposing, in this context, means that an API essentially makes the features of an application available for consumption by authorized external services. 

When interacting with an API, you select specific endpoints that cater to your use case. For example, if you want to fetch some information, you will access the particular API endpoint exposed precisely for this purpose.

How do API endpoints operate?

API endpoints are dedicated gateways through which an application communicates with external parties. Here’s a step-by-step breakdown of how they work:

1. First, the API endpoint receives a request from a client. Every request to an API is sent to a specific endpoint. The requests typically follow a structured format and may contain the required parameters to perform an operation. For example, if an API endpoint exposes functionality to retrieve a user’s information, the request may contain data needed by the API to identify the user, like their username.

2. Second, The API endpoint parses and processes the request. In this step, the API endpoint ensures that the request adheres to the rules defined by the API. For example, it may authenticate the requesting user and then extract the necessary parameters from the request. If authentication fails or a required parameter is missing, the request is rejected.

3.  Next, the API endpoint moves into the action phase. The API endpoint performs the requested action once the request is parsed and validated. This action may involve fetching specific data from or adding new data to the database.

4. Then, the API endpoint generates a response message. Now, depending on the outcome of the previous step, the API endpoint prepares a response message. Among other things, this message contains the requested data and a response code to indicate whether the operation was successful. 

5. Finally, the API endpoint sends the response to the client. The response is dispatched via the same communication channel as the request. 

Examples of how API endpoints operate

To deepen our understanding of API endpoints, let’s consider some examples. 

Example #1

The following endpoint from the ButterCMS API offers a way to retrieve news pages in the English language:

GET https://api.buttercms.com/v2/pages/news/locale=en&auth_token=your_api_token

Let’s break it down:

• GET: This is the “HTTP method” part of the request that denotes the action we want to perform. In this example, we want to retrieve (get) some data. Other supported method types are POST, PUT, DELETE, and PATCH.

• https://api.buttercms.com: This is the base URL where the API (and all its endpoints) is hosted.

• /v2: This specifies the API version (version 2 in our case).

• /pages/news: This is the part of the URL that identifies the particular endpoint we want to access. 

•  locale=en: This is a parameter that we pass to the endpoint to filter the response and ensure that only English news pages are returned.

• auth_token=your_api_token: This is another parameter in which we provide the API token that the endpoint will use for authorizing our request.

Example #2

The following endpoint from the PayPal API is used to add tracking information for a batch of payments.

POST https://api-m.paypal.com/v1/shipping/trackers-batch 

Let’s break it down:

• POST: Indicates that we want to write (post) some data to the application/database.

• https://api-m.paypal.com: The base URL where the PayPal API (and its endpoints) are hosted.

• /v1: Highlights that this is the version 1 of the API.

• /shipping/trackers-batch: This is the name of the endpoint that encapsulates the desired functionality.

The actual payment tracking data will be included in the request that’s sent to this API endpoint.

What is a route and how does it differ from an endpoint?

The terms “route” and “endpoint” are sometimes used interchangeably. Even though they are closely related, they have different meanings.

A route is a location (typically a URL) used to identify endpoints. On the other hand, an endpoint is a function within an API that performs a particular operation. The difference is best explained using an example.

my-api/accounts/1234 

The above is an example of a route. It defines the location of our API’s endpoints but doesn’t specify the function/operation. If you compare it to our API endpoint examples, you will notice one key thing missing: the method part.

GET my-api/accounts/1234 

Once we add the method (GET) to the route, it becomes a specific endpoint. The same route may have other endpoints, like the following:

POST my-api/accounts/1234 

DELETE my-api/accounts/1234 

PATCH my-api/accounts/1234 

Each endpoint serves a distinct purpose, yet they are all derived from the same route.

API endpoint best practices

When developing API endpoints for your application, it’s recommended to follow these best practices:

• Use clear, concise, and descriptive names for your endpoints that accurately reflect the functionality they offer.

• Use versioning (like in the examples above) to manage changes to your API endpoints. Ensure that newer API versions are backward compatible.   

• Adhere to RESTful principles to create intuitive and standardized endpoints. This makes it easy for other developers to use your API.

• Use stringent security controls to protect your API from unauthorized access. For example, use API keys or tokens for authentication, implement SSL/TLS for secure communication, and leverage rate limiting to prevent resource abuse.

• Thoroughly document your API endpoints. Include information about their functionalities, expected input and outputs, and error handling. 

Applying your knowledge of API endpoints

APIs are a staple of modern software development. Whether you are integrating with a cloud service, a CMS, a social media platform, a payment gateway, or a data provider, APIs are the key to seamless communication and data exchange. 

Suppose you are building an application that offers real-time weather forecasts based on a user’s location. To fetch weather data, you can integrate your app with a publicly accessible weather API. Here’s how you can go about it:

1. Choose a reliable weather API provider.

2. Read the documentation on the provider’s website to select the API endpoint(s) for your app’s needs. 

3. Sign up for an account with the API provider and obtain an API key.

4. Using an HTTP library, send an authorized request to the selected API endpoint to fetch the required data. 

5. Parse the response and display it on the app screen as needed.

6. Implement error handling mechanisms to process any errors that may occur during API calls.

In summary

API endpoints are a foundational concept in web development. They highlight a specific location where you can invoke an API to perform a specific action. This post aimed to offer a short and sweet introduction to API endpoints. We hope you found it useful.