How to Create Free Mint NFT Rewards with Callback Verification

Free Mint NFT Reward will allow the winners to mint an NFT for free on your website, and it’s similar to whitelist, but your team doesn’t need to manually upload a whitelist with all the qualified add

With the successful integration of the API callback, winners will be able to mint their own NFT on your website via a specific URL containing their track_id and eligibility.

Please follow the steps to create Free Mint NFT reward and to integrate API callback.

Step 1

Enter a reward name, number of winners, and upload an image of that reward.

Step 2

After that, you will need to get url params (something like track_id=Edg1Y475BiU) from your website and parse out the trackId.

About track_id:

  • TrackId is necessary to detect the user's participation in the task and to verify it. We will detect when a user clicks to participate in the task, the ?trackId={{trackId}} will be used for detection.

  • You will see the ?trackId={{trackId}} applied to your website link:

If your website link is

the visitors may come to your site via the link

Step 3

Next, please copy the API key we provide you to integrate it with your website.

Then enter the parameters according to the rules of const data, and encrypt the whole const data using the standard HmacSHA256 algorithm.

Step 4

Use our official API below and pass the corresponding parameters in the following code.

Official API:

const api_key = "3lhpTSAJd6XDgBe4XWcozob4iMmYUlkPc9c4fwnoydGk4Bh5lSA3qrSiqgXeJcX7"; // your api_key 

const { track_id} = queryString.parse(; 

const timestamp=new Date().getTime() 

const data = `track_id=${track_id}&timestamp=${timestamp}` 

const sign = crypto.HmacSHA256(data, api_key).toString(); // HmacSHA256 

fetch("", { 
method: "POST",
headers: { 
"Content-Type": "application/json", 

body: JSON.stringify({ 
}).then(async (res) => { 
console.log(await res.json()); 

Step 5

After the above steps are completed, enter your website link and click the ‘Check API callback’ to test it.


Each project you created on Cwallet Giveaway Tool will have a unique API key, and it will not change. So you only need to integrate once for a website. Also, you will be able to create Free Mint NFT reward on multiple websites if you need to.

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