๐Ÿšฉ Challenge 3: NFT Minting

๐ŸŽซ Setup your own NFT collection and minting site while learning the basics of the Flow blockchain and Cadence. You'll use:

  • The local Flow emulator to deploy smart contracts.
  • The local Flow dev wallet to log into test accounts.
  • A template Next.js app with sample scripts and transactions to interact with your contract.

๐ŸŒŸ The final deliverable is a DApp that lets an admin create an NFT Collection and display available NFTs for purchase on a minting site. Users will be able to see their purchased NFTs as well.

๐Ÿ’ฌ Meet other builders working on this challenge and get help in the Emerald City Discord!


Video Walkthrough

Want a video walkthrough? Check out Jacob Tucker's walkthrough here: COMING SOON


๐Ÿ“ฆ Checkpoint 0: Install

Required:

  • Git
  • Node (๐Ÿงจ Use Node v16 or a previous version as v17 may cause errors ๐Ÿงจ). You know you have installed it if you type node -v in your terminal and it prints a version.
  • Flow CLI (๐Ÿงจ Make sure to install the correct link for your system ๐Ÿงจ). You know you have installed it if you type flow version in your terminal and it prints a version.
git clone https://github.com/emerald-dao/3-nft-minting.git

in a terminal window, ๐Ÿ“ฑ install the dependencies start your frontend:

cd 3-nft-minting
npm install
npm run dev

in a second terminal window, start your ๐Ÿ‘ทโ€ local emulator:

cd 3-nft-minting
flow emulator start -v

Note: the -v flag means to print transaction and script output to your local emulator

in a third terminal window, ๐Ÿ’พ deploy your contract and ๐Ÿ’ธ start your local wallet:

cd 3-nft-minting
flow project deploy
flow dev-wallet

You can flow project deploy --update to deploy a new contract any time.

๐Ÿ“ฑ Open http://localhost:3000 to see the app


๐Ÿ‘› Checkpoint 1: Wallets

We'll be using the local Flow dev wallet.

Click the "Connect" button and notice a window appears with different accounts to select, each with their own Flow Token balance. Select the first account to log in to it.


โœ๏ธ Checkpoint 2: Minting some NFTโ€™s

Before we allow users to purchase NFTs, we have to mint them first!

In a terminal, run npm run mint

mint NFTs transaction

This will mint 3 NFTs and store them in the contract. They will be ready for purchasing.

Go back to your application and refresh the page. You will now see some NFTs available for purchase!

NFTs now appear on the frontend

๐Ÿ“˜ Checkpoint 3: Purchase NFTs

Now that there are NFTs available for purchase, we can go ahead and buy some NFTs.

Make sure you log in to the Service Account, since that account already has a lot of Flow Tokens to buy with.

Click Purchase on any of the available NFTs.

purchase nft tx

If you click approve, you will see that the NFT successfully gets taken off the market and put under the "Purchased NFTs" category:

nft is now purchased

๐Ÿ’พ Checkpoint 4: Fund an Account

Before we try to purchase with another account, we have to make sure they have enough Flow Tokens to buy with.

Log out if you are already logged in, click "Connect", and click "Manage" next to Account A:

manage button

Click "Fund" a few times, and then press "Save"

fund account

Now you will have enough Flow to purchase with Account A. Try to buy an NFT!

After buying an NFT, you should notice the balance of the account decrease.


๐Ÿ’พ Checkpoint 5: Deploy it to testnet!

๐Ÿ“” Ready to deploy to a public testnet?!?

๐Ÿ” Generate a deployer address by typing flow keys generate --network=testnet into a terminal. Make sure to save your public key and private key somewhere, you will need them soon.

generate key pair

๐Ÿ‘› Create your deployer account by going to https://testnet-faucet.onflow.org/, pasting in your public key from above, and clicking CREATE ACCOUNT:

configure testnet account on the website

After it finishes, click COPY ADDRESS and make sure to save that address somewhere. You will need it!

โ›ฝ๏ธ Add your new testnet account to your flow.json by modifying the following lines of code. Paste your address you copied above to where it says "YOUR GENERATED ADDRESS", and paste your private key where it says "YOUR PRIVATE KEY".

"accounts": {
  "emulator-account": {
    "address": "f8d6e0586b0a20c7",
    "key": "5112883de06b9576af62b9aafa7ead685fb7fb46c495039b1a83649d61bff97c"
  },
  "testnet-account": {
    "address": "YOUR GENERATED ADDRESS",
    "key": {
      "type": "hex",
      "index": 0,
      "signatureAlgorithm": "ECDSA_P256",
      "hashAlgorithm": "SHA3_256",
      "privateKey": "YOUR PRIVATE KEY"
    }
  }
},
"deployments": {
  "emulator": {
    "emulator-account": [
      "NonFungibleToken",
          "MetadataViews",
          "ExampleNFT"
      ]
  },
  "testnet": {
    "testnet-account": [
      "ExampleNFT"
    ]
  }
}

Notice that we do not want to re-deploy NonFungibleToken or MetadataViews. That is because they are already deploy and live on Flow testnet!

๐Ÿš€ Deploy your ExampleNFT smart contract:

flow project deploy --network=testnet
deploy contract to testnet

Lastly, configure your .env file to point to Flow TestNet so we can interact with your new contract.

In your .env file, change the following:

  1. NEXT_PUBLIC_CONTRACT_ADDRESS to your generated testnet address
  2. NEXT_PUBLIC_NFT_STANDARD_ADDRESS to 0x631e88ae7f1d7c20
  3. NEXT_PUBLIC_TOKEN_STANDARD_ADDRESS to 0x9a0766d93b6608b7
  4. NEXT_PUBLIC_FLOW_TOKEN_ADDRESS to 0x7e60df042a9c0868
  5. PRIVATE_KEY to your private key
  6. NEXT_PUBLIC_ACCESS_NODE to https://rest-testnet.onflow.org
  7. NEXT_PUBLIC_WALLET to https://fcl-discovery.onflow.org/testnet/authn

You can now terminate all your terminals since we no longer need to run our own local blockchain or wallet. Everything lives on testnet!

Run npm run dev to start your application in a terminal.

On http://localhost:3000/, click "connect" and log in to your Blocto or Lilico wallet, making sure to copy the address you log in with.

logging into discovery

In a terminal, run npm run mint

In your terminal, you should see a printed "Transaction Id". If you go to Testnet Flowscan and paste in that Transaction Id, you should see information about that minting transaction.

You should now see all the NFTs available for purchase!

*Note: If you want to fund a testnet account with Flow Tokens to test your application, you can use the Testnet Faucet


๐Ÿ“ Make Edits!

๐Ÿ” You can also check out your smart contract ExampleNFT.cdc in flow/cadence/ExampleNFT.cdc.

๐Ÿ’ผ Take a quick look at how your contract get deployed in flow.json.

๐Ÿ“ If you want to make frontend edits, open index.js in pages/index.js.

โš”๏ธ Side Quests

๐Ÿƒ More challenges coming soon...

๐Ÿ’ฌ Meet other builders working on this challenge and get help in the ๐Ÿ’Ž Emerald City Discord!

๐Ÿ‘‰ Problems, questions, comments on the stack? Post them to the ๐Ÿ’Ž Emerald City Discord.