As modern web development evolves, the desire to communicate effectively with people sets a significant precedent. To meet the communication demand of technology, we need to find a way to make technologies talk to each other. That's where APIs and webhooks come into the picture.
Both webhooks and APIs enable syncing and relaying data between two applications. However, both have different modus operandi and thus serve slightly different purposes. To clear up any confusion between the two, let's look at the differences between a webhook and an API and what kind of scenario each is most appropriate.
API vs Webhook: The Difference in Clear Terms
API stands for Application Programming Interface, a software intermediary that allows two applications to talk to each other.
In other words, an API is a messenger that delivers your request to the provider you're requesting it from and then responds to you. On the other hand, Webhook, also called reverse API, web callback, or an HTTP push API, is a way for an app to provide other applications with real-time information. It delivers data as an event happens or almost immediately.
APIs are request-based, meaning that they operate when requests come from 3rd party apps. Webhooks are event-based, meaning they will run when a specific event occurs in the source app.
To use a real-world analogy, APIs would be likened to you repeatedly calling a retailer to ask if they've stocked up on a brand of shoes you like. Webhooks would then ask the retailer to contact you whenever they have the shoes in stock, which frees up time on both sides.
Webhooks are less resource-intensive because they save you time on constantly polling (checking) for new data.
The main difference between them is that webhooks do not need to request a response, while API demands requests to get a response. In other words, webhooks receive while API retrieves.
What is the definition of a Webhook?
Webhooks are one way that apps can send automated messages or information to other apps. It's how Twilio routes SMS and phone calls to your number, how WooCommerce can notify you about new orders in Slack, MailChimp uses a webhook to signup users from your website to your newsletter.
They're a simple way your online accounts can interact with each other and get notified automatically when an event occurs. You'll need to know how to use webhooks to push data from one app to another. Webhooks make real-time very simple.
What is an API, exactly?
API is not event-based. They are request-based. Whenever we submit a form or make a post or a comment on Twitter or any social platform, we send data from the client side to the server down to the database. APIs are triggered by requests, whether you're sending or requesting data.
You could have an API that Creates, Reads, Updates, or Deletes data based on a request. For API, the demand begets a response.
Although real-time is possible with API, it requires an extra configuration from a web developer, making webhooks the most suitable mechanism for real-time information.
When to Use Webhooks
Webhooks usually act as a messenger for smaller data. It helps to send and extract real-time updates.
One of the most suitable scenarios for using a webhook is when your app or platform requires a real-time feature, and you don't want to use an API because you don't want to get entangled with the setups and waste resources in the process. In such instances, a webhook framework will be most beneficial.
Another best use case for using a webhook is where an API isn't provided or the available API isn't the best fit to act; a webhook could be used in such a situation.
Webhooks can be considered a perfect and sometimes even essential complement to API-based application integration.
Here are some outlines from Agility CMS on other use cases of using a webhook:
- They are clearing and managing a custom cache in an external system such as a website, mobile application, or database.
- We provide a way to sync content/data for integrations with third-party systems (i.e. Salesforce, Mailchimp, etc.).
- We are building custom content workflows.
- Kick off a CI/D pipeline to redeploy your website when content has been updated - this is often used for JAMstack sites that are built using static site generators.
Content Webhooks allow external applications or websites to become aware of content changes within your Agility CMS instance.
It works by providing a list of URL endpoints to Agility CMS. Each time content changes or is published in the CMS, Agility will notify each endpoint and pass on a message representing the exact change that occurred.
When To Use APIs
APIs work incredibly well when you're sure of constant incremental changes in data. Relatively stagnate data doesn't need an API. For example, if you're an eCommerce store that regularly has to track data or update some shipping status, then an API would be the best bet.
You need to "call" it regularly to obtain data updates through API. So, one can say that APIs are an excellent fit for application integration when you know you will have a constant change of data.
APIs are still popular for several reasons:
- Not every application supports webhook integrations.
- Sometimes you only want to know about the result rather than every event (i.e. every permutation) that's changed an object.
- Webhooks can only notify you about an event, so if you want to change based on new information, you'll need an API.
- A webhook payload may not contain all the data you need about an event. Hence an API is used.
Both APIs and webhooks have different use cases, but if your goal is to transfer data between two services, webhooks are the way to go. However, an API should be used if your platform or application demands frequent data changes.
You could use both APIs and webhooks to create a system that can communicate the right data types as it suits your application.