Go to https://webhook.site/ and use the given unique url to immediately inspect and test notifications sent by Multichain.
Step 4:
🔥
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).
Javascript
Python
1
functionisValidSignature(request){
2
const secretKey ='Secret Key provided by Multichain on the Project (View Key) list popup';
3
const headers = request.headers;
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const signature = headers['multichain-api-key'];// Lowercase for NodeJS
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const body = request.body;
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const hmac = crypto.createHmac('sha256', secretKey)// Create a HMAC SHA256 hash using the auth token
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hmac.update(body,'utf8')// Update the token hash with the request body using utf8
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const digest = hmac.digest('hex');
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return(signature === digest);// If signature equals your computed hash, return true
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.
Note that webhook notification max retry is
5
times; Notification will stop if no 200 OK response from your application is received within the retries.
🔔
You may however manually re-send the notification from the user dashboard under the "Subwallet Deposits" tab. (Image reference below.)
Re-send webhook notification to your application manually.