# Notify URL (Webhook)
**Step 1:** Select "Configure Webhook" from "Projects" on Dashboard.
**Step 2:** Input your webhook URL into the field provided and click "Save"
**Step 3:** Send test notification to webhook url for development purposes.
### 🔔 Sample notification *`POST`*to your webhook url
```
{
"type": "DEPOSIT",
"network": "TRON",
"status": "SUCCESS",
"hash": "cd2df87daa2001c678f5be970851278987a45132f165f62e5f1e1987c43d5cf7",
"fromAddress": "TDmarSrhZg7LaUaQyzez7UA2EZrCLWXEjw",
"toAddress": "TTcVb5oLA7UDGCDvTs7DtQo9ktJWgYPCkC",
"contractAddress": "TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t",
"value": "787.41",
"assetName": "Tether USD",
"assetSymbol": "USDT",
"networkFee": "1",
"platformFee": "3.93705",
"timestamp": 1618564124
}
```
{% hint style="info" %}
Go to and use the given unique url to immediately inspect and test notifications sent by Multichain.
{% endhint %}
**Step 4:** :fire: Validating data received at callback URL (Webhook)\
It is considered standard practice to respond with `200 OK` once you have successfully received a webhook callback (notification).
{% tabs %}
{% tab title="Javascript" %}
```javascript
function isValidSignature(request) {
const secretKey = 'Secret Key provided by Multichain on the Project (View Key) list popup';
const headers = request.headers;
const signature = headers['multichain-api-key']; // Lowercase for NodeJS
const body = request.body;
const hmac = crypto.createHmac('sha256', secretKey) // Create a HMAC SHA256 hash using the auth token
hmac.update(body, 'utf8') // Update the token hash with the request body using utf8
const digest = hmac.digest('hex');
return (signature === digest); // If signature equals your computed hash, return true
}
```
{% endtab %}
{% tab title="Python" %}
```python
import hmac
import hashlib
import json
def isValidSignature(request):
secretKey = '';
headers = request['headers'];
signature = headers['multichain-api-key'];
body = request['body'];
string_body = json.dumps(body, separators=(',', ':'))
digest = hmac.new(
bytes(secretKey, 'utf-8'),
msg=bytes(string_body, 'utf-8'),
digestmod=hashlib.sha256
).hexdigest()
return (signature == digest);
```
{% endtab %}
{% endtabs %}
Make sure only to **store validated transactions by type `DEPOSIT` using `hash` as the *****unique - primary key*** which will reject and prevent duplicated deposits in any case where your system receives a repeated webhook notification.
{% hint style="info" %}
Note that webhook notification max retry is :digit\_five: times; Notification will stop if no **`200 OK`** response from your application is received within the retries.\
\
:bell:You may however manually re-send the notification from the user dashboard under the "Subwallet Deposits" tab. (Image reference below.)
{% endhint %}
