Examples of Webhooks using REST API

Explore practical examples of Webhooks using REST API to enhance your application integrations.
By Jamie

Understanding Webhooks with REST API

Webhooks are a powerful way for applications to communicate with each other in real time. Unlike traditional APIs, which require polling for data, webhooks send data as soon as an event occurs, making them more efficient for both server and client. In this article, we’ll explore three practical examples of webhooks using REST API across different contexts.

Example 1: GitHub Repository Webhook for CI/CD

In a continuous integration/continuous deployment (CI/CD) pipeline, webhooks can automate the process of triggering builds when changes are pushed to a repository. This example uses GitHub webhooks to notify a CI server when a new commit is made.

When a developer pushes code to a GitHub repository, a webhook can be set up to send a POST request to the CI server endpoint, triggering the build process. 

{
  "ref": "refs/heads/main",
  "before": "abc123",
  "after": "def456",
  "repository": {
    "id": 123456,
    "name": "my-repo",
    "full_name": "user/my-repo"
  },
  "pusher": {
    "name": "developer",
    "email": "dev@example.com"
  }
}

In this JSON payload, the webhook sends information about the commit, the repository, and the pusher. The CI server processes this information and initiates the build.

Notes:

  • Ensure the CI server endpoint is secured with authentication tokens to prevent unauthorized access.
  • Customize the webhook settings in GitHub to filter events according to your needs, such as only triggering on push events.

Example 2: Stripe Payment Notification Webhook

Stripe, a popular payment processing platform, uses webhooks to notify merchants about payment events such as successful charges or failed transactions. This example illustrates how a webhook can be used to manage payment notifications.

When a payment is successful, Stripe sends a webhook to the merchant’s server with the payment details:

{
  "id": "evt_1J2Y4D2eZvKYlo2C1O3vF7gJ",
  "object": "event",
  "type": "payment_intent.succeeded",
  "data": {
    "object": {
      "id": "pi_1J2Y4B2eZvKYlo2C2Z3vF7gH",
      "amount": 2000,
      "currency": "usd",
      "status": "succeeded"
    }
  }
}

This JSON payload informs the merchant’s server of the successful payment, allowing them to update their database, send confirmation emails, or trigger other business logic.

Notes:

  • Verify the webhook signature to ensure that the request is indeed from Stripe, preventing fraudulent notifications.
  • Use the Stripe dashboard to manage and test webhooks easily.

Example 3: Slack Message Notifications with Webhooks

Slack provides incoming webhooks that allow developers to send messages to Slack channels from external applications. This example demonstrates how a service can send alerts to a Slack channel when certain events occur, such as a server going down.

When a server detects an issue, it can send a POST request to a Slack webhook URL:

{
  "text": "Alert: Server is down!",
  "channel": "#alerts",
  "username": "ServerMonitor",
  "icon_emoji": ":warning:"
}

This payload sends an alert message to the specified Slack channel, notifying the team of the server’s status. Teams can respond quickly to resolve issues.

Notes:

  • Customize the message format using Slack’s rich formatting options to make alerts more informative.
  • Set up multiple webhooks for different channels to categorize alerts accordingly.

Conclusion

These examples of webhooks using REST API showcase how different applications can use this technology to improve real-time communication and automation. Whether it’s for CI/CD, payment notifications, or team alerts, webhooks can greatly enhance the efficiency of your systems.