What is a Shopify Webhook?

A webhook is a tool or piece of software that allows events from your Shopify store to automatically trigger a corresponding notification to other applications, so that you (or an automatically working application) can be notified and act on the event.

Webhooks have the following components:

1. Events

As seen in Shopify's webhook documentation, there is a list of different supported webhook events and topics. Topics are what exactly you are interested in regarding that object. For example, for the cart, you can be notified whenever a cart gets updated simply by subscribing to the carts/create topic.

2. Subscriptions

Developers are able to subscribe to notifications associated with the events they would like to know.

3. Notification URL

When events occur, webhooks send a POST request with event data to each notification URL set to listen for the event type.

4. Notification Body

Developers will get the details about the event in the notification Body.

Webhooks are a fantastic way to elevate your business. In our article, "How To Create Webhooks in Shopify", we dive in to how you Shopify merchants can use webhooks to automatically handle events such as new clients and orders. We also explore why Shopify's inventory-related webhooks are an essential part of managing the day-to-day operations of your business in our "In-Depth Guide to Shopify Inventory Webhooks". Make sure to check out these two articles to get a taste of how you can increase your store's success by implementing webhooks.

How Do Webhooks Work?

Webhooks are sent to their corresponding apps as a notification if a certain event occurs on your Shopify store, and each message contains either a JSON or XML file along with metadata in the HTTP headers. For an app to receive these notifications, it uses the REST Admin API or the GraphQL Admin API to create a data object known as a 'webhook subscription'. The webhook subscription provides the information regarding the topic in question (i.e. the event which triggers the webhook) as well as the app which is receiving the information.

To start off, your app subscribes to one of these specific topics. These topics cover every possible event in a Shopify store, such as updates to a cart or at checkout. Then, whenever an event in the topic’s class of events occurs, the webhook subscription sends a webhook to the app with a JSON or XML file as a message.

Why Should You Use Webhooks With Your Shopify Store?

There are many benefits webhooks offer for Shopify merchants. One of the main advantages that comes is that your app does not have to continually check Shopify to see if an event has occurred, which can save you time and money. As a result, webhooks can also increase the efficiency and optimization of your operations.

For example, you may want to alter information about a customer or an order in an internal database, or you might need to send notifications to clients or inventory management/shipping companies. It’s also possible to integrate webhooks with accounting software to stay up to date on the financial side of your business. Regardless of your reason for using them, the implementation of webhooks is a powerful mechanism that can power your Shopify store and your business as a whole.

What’s the difference between a webhook and an API?

Application Programming Interface (API) can access data from a third party and allows different apps and services to exchange information. For example, the weather app on your phone uses the API of a third party to retrieve weather predictions. A webhook is a POST request that is sent to a specific URL. Sometimes people call webhooks reverse APIs, which lets you skip a step. The webhook feature reduces the additional cost of manually polling API for new data that can bring to your systems.

The significant difference between API and webhooks is that API requires us to send a request to the server, and the server sends data back to your system or application. However, webhooks are different as they will automatically send data if any data is available at a particular point. Therefore, API sends requests and receives the data back, whereas webhooks always trigger data to the URL as long as they are available.

Webhooks Available For Each Shopify API

Shopify has two main APIs:

1. Admin API

We use the admin API to integrate with apps, services, features within a Shopify store. For example, if you want to collect email addresses on your front page and pass these email addresses to your third-party email marketing tool, then you would use the admin API.

2. Storefront API

On the other hand, the storefront API creates a shopping experience outside a Shopify store, allowing customers to buy products in different places in your online store.

For more information on how to configure a webhook for your app using different APIs, you can refer to Shopify's Guide on Webhooks.