Re-defining Trading Cards using Dynamic NFTs
Tags: web3, blockchain, javascript, tutorial
Published: 2022-10-27 10:37:05

Over the past year and a half, Non-fungible tokens (NFT) have gained a lot of traction, but the next generation of NFT’s will be dynamic. Dynamic NFT’s give us an opportunity to explore a new level of interpretability for NFT’s and other tokens, as it allows us to alter the metadata of our NFT. The ‘dynamic-ness’ of the NFT is often dependent on some online or IRL event such as a piece of art or character updating based on weather data, real life sport scores or even simple user activities. In this article we will be looking at a simple example of a dynamic NFT, combining trading cards and their attributes being updated based on simulated sports data.

### Introduction to Revise

Revise is a platform that’ll let you build dynamic NFTs. NFTs today are fairly static. Once you buy it they don’t change. What you see is what you get. Dynamic NFTs are able to react to the outside world, to data, to user interactions, etc. They are capable of changing, and evolving over time. 

Let’s use Revise to build your own football team NFT collections, then add NFT’s too it and allow them to change dynamically. We won’t cover how to deploy these NFTs to Ethereum/Opensea ([click here to learn more](https://dev.to/anil_from_revise/how-to-publish-your-nft-on-opensea-testnet-3n29)).

### Create a Repo

Let’s clone this [GitHub repo](https://github.com/revise-network/nft-tutorial-1) to get started. The repo is an empty Javascript project with [revise-sdk](https://www.npmjs.com/package/revise-sdk) added to the package manager. Once you `cd` into the project folder, you can run `npm install` to install all the dependencies. Let’s create an `index.js` file. We’ll write all our code in this file, we’ll use `node index.js` to run the program.

Copy and paste the following code into the `index.js` file.

```jsx
const { Revise } = require("revise-sdk");
const AUTH_TOKEN = "...PASTE YOUR AUTH TOKEN HERE...";
const revise = new Revise({auth: AUTH_TOKEN});

async function run() {

	// write your code here

}
run()
```

In the first couple of lines, we’re importing the [Revise-sdk](https://www.npmjs.com/package/revise-sdk) and adding our auth token (more on how to get this below). In the third line, we’re instantiating the `revise` object. We can now use this object to call all the functions needed to complete the exercise. Revise functions are mostly async, so we create a `run` function which is async and can call the revise functions using the `await` keyword. This will make our code more readable and maintainable.

<aside>
💡 You can generate the Auth token from app.revise.network. For more details refer to the next section of this article.

</aside>

### Generate API Key (Auth Token)

Before we continue writing the rest of the code let’s go grab an auth key. Visit [Revise](https://revise.network?utm_source=webinar&utm_medium=video&utm_campaign=ua&utm_id=ap) and click on “get started”. Once you make an account and log in you’ll see the “generate API key” link in the header. Click on it, you should now be able to generate the API key (auth token). Copy the key that is shown on the screen and keep it safe. This key is not stored on Revise’s servers for security reasons. If you misplace the key it’s permanently lost. You can always come back and generate a new key.


![Generate API key](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/aonmyh42sa78ug4gahm5.png)

Let’s replace the `AUTH_TOKEN` in the above code with the key we just generated. Now we’re ready to start writing out Dynamic player NFT.

### Add a Collection

To start with let’s make a collection called “My Dynamic Football Team”. This collection can have multiple NFTs. Each NFT is a player trading card. In order to make the collection, we’ll call the `addCollection` function. We’ll have to pass it two parameters, the name for the collection and the URI for the collection. The `collectionURI` is a unique project name that can be used to generate links for the NFT (why we need these links is described later). We have to make sure that the URI is unique and a single word. For e.g. “myfootballteam" is a valid Collection URI “my football team” is not. Add the following code to your `index.js` inside the `run` function.

```jsx
const collection = await revise.addCollection({name: "My Dynamic Football Team", uri: "..CREATE YOUR UNIQUE URI"})

// Collection Name : Use any name you want for your collection (this gets shown in the marketplace))
// Collection_URI  : Use a unique name (no spaces or special characters)
//                   this will generate a unique link for your collection
//                   for e.g. if you choose "mydynamicplayer12345"
//                   your baseURI wil be "mydynamicplayer12345.revise.link"
```

### Add an NFT

Now let’s add our first NFT player. We’ll use the `addNFT` function to create our player. Add the following code to your `run` function below the `addCollection` function call.

```jsx
const nft = await revise.addNFT({
    image: 'https://revise-testing.fra1.cdn.digitaloceanspaces.com/players/bronze.png',
    name: 'Kylian Mbappe',
    tokenId: '1',
    description: 'Forward with exceptional abilities. Legend to have on your team'
  }, [
    {team: "PSG"}, {position: "Forward"}, {level: "Bronze"}, {offense: "75"}, {defense: "45"}, {stamina: "76"}, {skill: "71"}
  ], collection.id)

console.log(nft)
```

We’re passing parameters for the image of our player, the name, description, `tokenId` and some properties. We’re also passing the `collectionId` we received after creating our collection for the earlier code snippet. `tokenId` is the unique ID of your NFT on the blockchain. This helps the blockchain and marketplaces distinguish between the NFTs part of the same collection. Two NFTs shouldn’t have the same `tokenId`. We can add any amount of custom data to our NFTs via its attributes. As you can see in the above snippet we’ve added “team”, “position“, offense”, “defense”, “stamina” etc. You can add any number of attributes here.

### Run

The final state of our `index.js` file should look like this now.

```jsx
const { Revise } = require("revise-sdk");
const AUTH_TOKEN = "...PASTE YOUR AUTH TOKEN HERE...";
const revise = new Revise({auth: AUTH_TOKEN});

async function run() {

	const collection = await revise.addCollection({name: "My Dynamic Football Team", uri: "..CREATE YOUR UNIQUE URI"})

	const nft = await revise.addNFT({
    image: 'https://revise-testing.fra1.cdn.digitaloceanspaces.com/players/bronze.png',
    name: 'Kylian Mbappe',
    tokenId: '1',
    description: 'Forward with exceptional abilities. Legend to have on your team'
  }, [
    {team: "PSG"}, {position: "Forward"}, {level: "Bronze"}, {offense: "75"}, {defense: "45"}, {stamina: "76"}, {skill: "71"}
  ], collection.id)

console.log(nft)

}
run()
```

Let’s run this file to create a collection and add our first NFT. Run `node index.js` in your terminal. The expected output is an `id` as shown below. 

![run nodejs command](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/3gue0o4ylxqauqzqlm5d.png)

The command you ran earlier should output the id for the NFT we just created. The ID is the unique identifier for this NFT, we’ll be using this `nftId` to fetch and makes updates to our player. **Let’s store this ID carefully.**

<aside>
💡 Note: the `tokenId` and `nftId` are different. `tokenId` is used by marketplaces and wallets to identify your NFT. `nftId` is used by Revise to identify and control the NFT.

</aside>

Visit your [Revise dashboard](https://app.revise.network?utm_source=webinar&utm_medium=video&utm_campaign=ua&utm_id=ap) to see your NFT player in action.

![NFT list view](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/9cuyxwc4sb7a64ppd1hc.png)

Click on the “View” button to see your NFT and it show show up with the Bronze image.

![player profile](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/e9ssne9v1lncoi0v8iio.png)

### Adding dynamic capabilities to your NFT

Now that we’ve created our first NFT player, let’s make him dynamic by changing its moods.

Create a new file called `levels.js`. Paste the following code in the file.

```jsx
const { Revise } = require("revise-sdk");
const AUTH_TOKEN = "...AUTH_TOKEN...";
const revise = new Revise({auth: AUTH_TOKEN});

const API = async function() {
  const options = [
    {level: 'Silver', offense: '82', defense: '51', stamina: '82', skill: '79', image: "https://revise-testing.fra1.cdn.digitaloceanspaces.com/players/silver.png"},
    {level: 'Gold', offense: '98', defense: '64', stamina: '92', skill: '87', image: "https://revise-testing.fra1.cdn.digitaloceanspaces.com/players/gold.png"}
  ]
  const randomIndex =  Math.floor(Math.random() * 2)
  return options[randomIndex];
}

async function run() {

  revise.every('2m').listenTo(API).start(async (data) => {
    const player = await revise.fetchNFT("0d6cee67-d3c1-41d5-bd57-ebbe4d34ebd3")
    revise.nft(player)
      .setProperty("level", data.level)
      .setProperty("offense", data.offense)
      .setProperty("defense", data.defense)
      .setProperty("stamina", data.stamina)
      .setProperty("skill", data.skill)
      .setImage(data.image)
      .save()

			console.log(`${player.name}'s is now at level ${data.level}`)
  })

}
run()
```

In the above code we’re setting up automation which will fetch a level every 2 mins and update our player attributes and image. Execute the above file by running `node levels.js`. The program will execute automatically and evolve our NFT player in the background. You should be able to see the player change it’s level to Silver or Gold and subsequent attributes and all the old versions (revisions) of the NFT as well.

![Revise dynamic NFT dashboard page](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/y3zz4diz9ni72snsbubd.png)

Congrats on creating your dynamic football collection and player NFT! [Publish your Player NFT to Opensea](https://dev.to/anil_from_revise/how-to-publish-your-nft-on-opensea-testnet-3n29) and show it off to the world.

If you want to learn more or explore opportunities creating with Revise, please schedule a call with us [here](https://calendly.com/anil-revise/dynamic-nfts-and-revise) or join [our Discord](https://discord.gg/47wkvCz3) or message us on [Twitter](https://twitter.com/ReviseNFT).