# Notify URL (Webhook)

**Step 1:** Select "Configure Webhook" from "Projects" on Dashboard.

![Configure webhook](/files/-MkD9HvhdG8u3x5slpJI)

**Step 2:** Input your webhook URL into the field provided and click "Save"

![Save your webhook callback url under "Projects"](/files/-MkD95VZ9vY67jSAG8lE)

**Step 3:** Send test notification to webhook url for development purposes.

!["Send test notification" option](/files/-MkD9vOGXzphU70uBeKg)

### 🔔 Sample notification *`POST`*&#x74;o your webhook url <a href="#sample-notification-post-to-your-webhook-url" id="sample-notification-post-to-your-webhook-url"></a>

```
{
  "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 <https://webhook.site/> 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 = '<your Secret Key goes here>';
    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 &#x20;*****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.\
\
&#x20;:bell:You may however manually re-send the notification from the user dashboard under the "Subwallet Deposits" tab. (Image reference below.)
{% endhint %}

![Re-send webhook notification to your application manually.](/files/-MlM5eTiM5fem1A05uRq)


---

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.multichain.info/start/notify-url.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.