# Webhook (LEGACY)

## **Legacy Webhook Notice**

You are currently using an older version of the Extracta LABS webhook listener.

This version is still **functional**, but it does **not support newer features** such as event types and structured payload handling ([webhook-event-types](https://docs.extracta.ai/data-extraction-api/webhook-event-types "mention")). To access the latest improvements, we recommend upgrading your webhook integration.

👉 Visit the **API page** in your **Extracta** **LABS dashboard** to update your webhook listener to the latest version. Upgrading ensures you get the most accurate, flexible, and future-proof webhook experience.

This is the new webhook: [webhook](https://docs.extracta.ai/data-extraction-api/webhook "mention")

***

## Description

Webhooks allow you to receive real-time notifications of events happening within your Extracta  LABS extractions. This section will guide you through setting up a Node.js server with Express to listen for and handle webhook events securely.

***

## Prerequisites

* Node.js installed on your server
* An Express.js application
* A secret key obtained from the Extracta LABS dashboard

***

## Step 1: Set Up Your Server

First, ensure you have Express and the necessary packages installed in your project. If not, you can install them using npm:

```bash
npm install express body-parser crypto --save
```

***

## Step 2: Implement Webhook Endpoint

Create a basic HTTP server with Express to listen for webhook POST requests. Use the following code snippet as a starting point:

{% code title="server.js" lineNumbers="true" fullWidth="false" %}

```javascript
const express = require('express');
const crypto = require('crypto');
const bodyParser = require('body-parser');

const app = express();
const port = 4000;

app.use(bodyParser.json());

// Your webhook secret key from the dashboard
const secret = 'secretKey';

// Middleware to validate the webhook signature
function validateSignature(req, res, next) {
  const sigHeader = req.headers["x-webhook-signature"];

  const signature = crypto.createHmac('sha256', secret.replace('E_AI_K_', '')).update(req.body.result).digest('base64');

  if (signature !== sigHeader) {
    return res.status(401).send({ message: "Webhook is not properly signed" })
  }

  next()
}

// Webhook endpoint
app.post('/webhook', validateSignature, (req, res) => {
  console.log('Webhook received:', req.body);
  
  // Process the webhook payload as needed
  // ...

  res.send({ message: "Webhook received" })
})

app.listen(port, () => console.log(`Server listening on port ${port}!`))
```

{% endcode %}

***

## Step 3: Test Your Webhook Listener

After setting up your webhook listener, test it by sending a simulated files. Ensure your server validates the signature and processes the event correctly.

***

By following these steps, you can securely set up your application to receive and process webhook events from Extracta LABS, enabling real-time updates and actions based on the events transmitted to your endpoint.