API Security

What is an API call?

What is an API call?


Mostly overlooked, API Call is a crucial aspect to understand as it’s the foundation of further detailed API functionalities. Just as we need a switch on the TV or need a keyboard to provide inputs to the laptop/computer, we need API Calls to call out data from another app/software. Created and exchanged in a huge amount, API Call is the most crucial aspect of the API ecosystem. Let’s learn more about it.

Learning Objectives

API Call Meaning

As we all know, API is the entity required for data exchange between two applications/software. When an API puts forward a request for data/functionality access to other applications/software, it’s known as API Calls. 

On a structural level, it’s the message that a certain API forwards to a server to build a connection with the API of other applications/software. It’s like a command or request, made with an invention to reduce the efforts and time consumed to access a piece of particular information.

If you’re trying to understand API Call vs request then they are more or less the same. 

Here is a simple example explaining the API Call meaning.

Suppose you searched “best flight tickets to Dubai” on Google.

Upon the receipt of the request, Google will send the API Calls to various service providers to know about their prices and availability. The details will be provided in the form for API only. Google will receive it and display the results to you. All of this happens very quickly.

API Call in Action 

When an API Call is generated, an API endpoint is defined for sure. The API endpoint is the source where the API Call will go or the resource that receives the API Calls. Most commonly, API Calls are received by servers or web applications. Hence, they are API endpoints - responsible for accepting the API Calls, processing them, capturing the information, and providing the response/answer/output.

To ensure that API Calls reach the desired API endpoint. To make this happen, each API Call features a URI. This is the industry standard to spot the right destination. Depending upon the situation, URI could be a server, application, email contact, or website.

In the case of web APIs, URI becomes URL. It is used to recognize the assigned internet destination. An ideal and viable URL is one featuring the application layer protocol like HTTP or HTTPS. HTTPS is more secure than HTTP and is mostly used by API security-concerned businesses.

However, HTTP-based API Calls are very common as most web APIs are HTTP-based. HTTP API Calls take the help of standard HTTP verbs that include POST, PUT, and GET. Based upon the HTTP verb used, API Calls decide what kind of info piece or data that API endpoint should proffer.

API Call in Action
API Call in Action

Examples of API Calls

As APIs are at the backstage of every responsive application, API Calls are everywhere. Let’s have a look at API Calls and how they might look. As Facebook is a well-known platform, we’re going to provide API Call examples in its context.  

GET https://api.facebook.com/1.1/followers/user_id.json

This API Call is enabled to produce any result as only an endpoint is defined. To make it more prompt and result-driven, a wide range of parameters can be added to the request.

Here is a little more complex example. 

GET https://api.facebook.com/1.1/followers/ids.json?cursor=-2&screen_name=smartsandy&count=1000

Now, a lot of actions will take place with this single API Call. For instance, the cursor will be set to -2 which will lead to basic pagination. Secondly, the screen_name parameter will target the user named ‘smartsandy.’

The third parameter, which is count set to 1000 limits, refers to the total number of Facebook user IDs included in a single request. Setting up this limit prevents data overflow.

How to Protect API Calls? 

If not handled with due diligence and security, API Calls can be a great threat to the API security and the IT infrastructure it is connected to. Insufficiently handled API Calls are prone to various threats as attackers can use them to carry out:

  • Dos or DDoS attack is a type of attack wherein verified or authorized users are restricted to access APIs. To avoid access or make APIs unavailable, threat actors send multiple API Calls to one API. The scenario results in a crowded or unresponsive API.
  • Various vulnerability exploits attacks. This attack-type deal is an already-vulnerable API and takes advantage of it. Depending upon the extent of the API exploit, an attacker could ask for sensitive information or prevent access to a particular API.

Hence, it’s very crucial to protect API Calls. The most common API Calls preventive measures, adopted by security experts, are as mentioned below:

  • Keep a track of API endpoints and understand where your API Calls are reaching.
  • Always verify API clients by using API authentication, implying only verified resources are sending API Calls to you. You can use mutual TLS and public-key cryptography for API Call authentication.
  • Take the help of a useful API security platform. Wallarm is a very extensive and feature-rich platform offering multiple security solutions for APIs. Capable of handling the security of all the leading API Calls, including REST API Calls and SOAP API Calls, this platform will help you keep track of API Calls from the creation to the delivery stage.  

Ending Notes

APIs are of no use without API Calls. So, stop ignoring this vital aspect of the API ecosystem and start comprising it in API security policy. When API Calls are secured, protected and verified results are generated.

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