Applications and online systems need to communicate with each other to accomplish tasks and provide real-time information. Take e-commerce apps; they need to communicate with multiple systems to provide live data as it occurs. Digital systems operate similarly to any other team — multiple members collaborate to accomplish a common goal. Think of webhooks as a team messenger whose primary goal is to alert you any time an event has occurred. Webhooks mentioned here are a method for automated communication between apps, enabling them to send real-time notifications and streamline integration.
As third-party web applications increase in popularity among companies, tools like webhooks help to provide an infrastructure that saves time, resources and improves the customer’s experience through event-driven automation. Webhooks are used to send automated messages and share data between applications. By enabling apps to send automated messages and share data instantly, webhooks streamline workflows and make it easier to integrate services effectively.
The Skinny on Webhooks
The “web” in webhook stands for website or web application (as these are the only places webhooks can work), and “hook” refers to a function that performs when an event occurs. Webhooks are a one-way, automated message sent as an HTTP request to another online service or application, and are often used to send notifications between systems.
A webhook’s sole purpose is to alert other online systems when an event has occurred. Once triggered by an event, a webhook will automatically send a message to specified systems, and in turn, the receiving system is activated to complete its own task.
For instance, say you’re a freelance developer who uses PayPal to invoice your clients. Every time your client pays an invoice, one app (PayPal) uses a webhook to connect to another app (your mail server), and you are notified by an automated email that the invoice has been paid.
In this scenario, paying the invoice is the event that triggers the communication from PayPal to your mail server. PayPal is the source (the initiating system) that sends the message via an HTTP request (shared data) to the destination, which is your mail server (the receiving system).
All of this is automatic, and on a single communication path, meaning the receiving system cannot reply to the source. In other words, your mail server cannot request or send any information back to PayPal.
Webhook Examples
Webhooks are a common form of communication amongst most applications and online systems. If you’re still not sure what a webhook’s purpose is, how they function, or how you can utilize them in your business — keep reading.
Let’s start with a simple example. Say you subscribe to Netflix, and every month they send you an email alerting you that your payment source has been charged. This notifies you that your bill has been paid and lets you know that money has been withdrawn from your account, which is both convenient and a useful security measure.
Netflix is able to provide this service by subscribing to your bank system (the source) to send a webhook whenever your debit card is charged. When this specific event happens—such as a payment being processed and new data becoming available—the bank system sends data immediately to a designated webhook URL configured by Netflix’s email service. The webhook payload contains details about the transaction, which is received by the receiving end (the email service). This allows the email service to take immediate action and generate a notification for you.
Unlike polling, where Netflix’s email service would have to repeatedly request data or retrieve data from the bank to check for updates, webhooks push new data automatically as soon as the event happens. This means there is no need to manually request data; instead, the system sends data and delivers information in real time, streamlining operations and improving user experience.
How Webhooks Are Used In Business
Here are a few examples of how businesses use webhooks. While users are navigating through e-commerce websites, the site monitors the user’s actions for a specified event. A specified event could be a user adding items to their shopping cart, abandoning their cart, making a transaction, etc. Webhooks can also be triggered by other events, such as user sign-ups, payments, or form submissions.
There’s a potential for growth here that could be easily overlooked. For example, a push notification to suggest a complementary product could be triggered when an item is added to the cart. Similarly, by reminding customers that they have items in their cart, the customer is more likely to return to complete their transaction.
Businesses use webhooks and third-party software to provide their users with transactional emails
How does this work? First, you need to integrate a webhook with your e-commerce platform and your transactional email provider, such as SendInBlueMailChimp, or Mailjet. Once these systems are integrated, the webhook communicates that a specified event has occurred, which automatically enables the other systems to send the appropriate transactional email.
Besides confirming the sale with the customer, there’s an opportunity here to showcase other products or services that the customer might also be interested in by generating and sending a customized email based on their purchase.
If your customer is licensing software, an email (or push notification, for an app) could be triggered when the license is due for renewal or the software detects that a more recent version is available. Webhooks can also be triggered by code updates, automatically initiating automation processes such as updating configuration files in Infrastructure as Code (IaC) scenarios. If your customer isn’t already a subscriber to your mailing list, they may not be aware that an upgrade has been released.
Push notifications and emails can also be triggered when legal notices (such as terms and conditions and privacy rights) are updated.
Businesses also use webhooks for security and safety measures, such as two-factor authentication protocols. For instance, an employee attempts to log into your business’ system on a new device; this could trigger the system to send an SMS text message with a code needed to complete the login.
The user attempting to log in would be considered an event. For the two-factor authentication system to work, you need to integrate a webhook with the platform and a messaging service like MessageBird. The action of sending the code through SMS text messaging is automated and occurs based on the trigger event.
Another Webhook example is push notifications that pop up due to a user's activity. Github, Trello, Google Calendar, and Microsoft Teams are platforms that support webhooks to send push notifications.
Google Calendar uses webhooks to send reminders of upcoming meetings. Github uses webhooks to communicate with team messaging systems like Slack to relay and sync critical internal changes. You can automate notifications for GitHub webhook events like pull requests and CI/CD runs, or Stripe webhook events like payments and subscriptions. Trello monitors changes within internal workflow systems to notify users when updates have been made to project boards or "cards." Microsoft Teams integrates with project management tools through webhooks, enabling real-time notifications and streamlined team communication.
Webhooks are often described as reverse APIs because, unlike traditional APIs where clients poll for updates, webhooks automatically push data to clients when a specified event occurs.
Ultimately, webhooks make it easy to integrate and use third-party software.
How Do Webhooks Work?
Webhooks are handy tools when working with third-party software that you don’t have full access to. There are essentially three basic steps to successfully set up a Webhook:
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Retrieve a unique url from the third-party application that you’d like to send info to (the destination).
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Include the unique url you retrieved from the destination app into the url field of the webhook section of the source application that you wish to receive data from.
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Specify the type of events you want the source application to alert you of, defining which specific event occurs or certain event will trigger the webhook.
Once the webhook is set up, everything will sit tight until one of the specified events occur. Once a certain event or specific event occurs, the source application will check its webhooks and push out identifying metadata (author, transaction information, date, etc.) to the receiving application’s URL.
HTTP Requests and Webhook URL
As we already learned, webhook messages are also known as requests sent via the HTTP protocol. When your web browser collects data from a website’s server, the request for that data needs to be specific as web servers can host a ton of information. The request must have a clear structure consisting of a URL, a body, a header, and a request method.
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URL: As mentioned above, the URL is obtained from the destination application. Essentially, the URL acts as the location that will receive requests from the webhook.
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Body: The body consists of sending the actual data, sometimes referred to as the “webhook payload.” Even though the request is sent via the HTTP protocol, the body can be sent in the form of JSON or XML format.
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Header: The header provides context that helps the data make sense.
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Request method: Webhooks typically use an HTTP POST request or HTTP POST to send data. The receiving application must be able to receive requests, often in the form of POST requests, and process the incoming webhook payload. Developers may need to write code to handle and parse this data. After processing, the application should respond with an appropriate HTTP status code to indicate success or failure.
POST, GET, PUSH, and DELETE Webhooks
To put it simply, the names genuinely say it all. The GET method does exactly what its name implies — it goes out and gets the information it needs from the server. The POST method posts or sends the event information to a website or application in the body. The PUSH method requests specific information from the server, typically for the purpose of updating it, and the DELETE method allows you to delete the webhook.
POST is the most popular method for webhook integrations as it allows you to include more information in the body. Applications often use the POST method to send webhooks, notifying other systems of events such as new items posted in RSS feeds or other automated triggers. You’ll know valuable metadata such as what event occurred, who triggered it, date and time, and other details.
Webhook Security Considerations
When using webhooks to connect apps and facilitate communication between web apps, security should always be a top priority. Every time an event occurs—such as a successful payment, a change in order status, or a new user registration—a webhook sends an HTTP request to a specified URL, often carrying sensitive customer data or key information about the event. Without proper webhook security, this data transfer could be intercepted, tampered with, or even exploited by malicious actors.
To protect webhook data and ensure secure webhook integrations, always use HTTPS for all webhook requests. HTTPS encrypts the data in transit, making it much harder for anyone to eavesdrop or alter the information as it moves between systems. Most webhook providers require a secure URL for this reason, especially when handling real time data or sensitive customer data in e-commerce applications.
Authentication is another critical layer of webhook security. Many webhook providers allow you to set up authentication tokens or a secret key, which are included in each webhook request. When your application receives webhook requests, it should verify these tokens or keys to confirm that the request is coming from a trusted source. This helps prevent unauthorized access and ensures that only legitimate events trigger actions in your system.
Validating the request body is equally important. Before processing any webhook data, your application should check that the request body matches the expected format and contains all necessary event data. This step helps prevent malicious payloads from causing harm or triggering unintended actions. In e-commerce, for example, this means verifying that order status updates or payment notifications are genuine before updating customer records or sending instant notifications.
Monitoring webhook deliveries is another best practice. By tracking webhook events, HTTP status codes, and any failed webhook deliveries, you can quickly identify potential security issues or misconfigurations. Many webhook providers offer dashboards or logs to help you monitor these events and respond to problems as soon as they arise.
To further enhance webhook security, consider implementing rate limiting. This technique restricts the number of webhook requests your application will accept in a given time frame, helping to prevent denial-of-service attacks or accidental overloads. Rate limiting is especially important when using webhooks to send data for high-traffic events or when integrating with multiple other apps.
By prioritizing webhook security—using HTTPS, authentication tokens, request validation, and monitoring—you can ensure that your applications receive webhook requests safely and reliably. Whether you’re sending instant notifications for successful payments, updating order status in real time, or sharing customer data between web apps, secure webhook integrations are essential for protecting your business and your users. Using webhooks securely not only safeguards sensitive data but also builds trust and reliability into your application development process.
Conclusion and Webhook Security
In a digital world ruled by quick information, businesses must offer their customers seamless experiences on the web. Webhooks are an excellent tool that provide a simplified way to share real-time data amongst online applications, increase your app’s efficiency, and mitigate mistakes. Webhooks enable you to communicate with third-party software to automatically notify your customers of important information whenever a relevant event occurs. In particular, webhooks provide instant notifications, ensuring that users receive real-time updates as soon as an event happens.
Understanding webhooks and incorporating them into the backend of your business applications can add value by improving your processes, enhancing the customer’s overall experience, and satisfying their need for swift information. If that’s not enough to convince you, MagicBell’s complete notification system allows you to centralize and sync all your internal and external notifications seamlessly. Stay organized while also ensuring that users don’t miss out on important announcements!