๐Ÿšฉ Challenge 1: NonFungibleToken

๐ŸŽซ Deploy your own NFT contract to learn 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 users create an empty collection, mint some pre-loaded NFTs, and transfer them to another account on Flow testnet.

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: Challenge #1 (NonFungibleToken) Walkthrough

๐Ÿ“ฆ Checkpoint 0: Install


  • 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/1-non-fungible-token.git

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

cd 1-non-fungible-token
npm install
npm run dev

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

cd 1-non-fungible-token
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 1-non-fungible-token
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 "Log In" 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.

๐Ÿ‘€ Checkpoint 2: See your NFTs

After logging in to the account with address 0xf8d6e0586b0a20c7, click the Get NFTs button. Notice that you get an error:

error when getting NFTs

The reason for this is because we haven't set up the user's account to be able to receive NFTs. On Flow, accounts needs to have a collection in their account to store specific NFTs. Let's set that up that now.

Click the Setup Collection button:

setup collection for user account

This will set up the user's account so it can receive NFTs.

Try clicking Get NFTs. You will see no NFTs appear. So let's mint some NFTs!

โœ๏ธ Checkpoint 3: Minting the NFTโ€™s

Now that we have set up the user's account, we can mint some NFTs to it.

In a terminal, run npm run mint 0xf8d6e0586b0a20c7

mint NFTs transaction

This will mint 3 NFTs to the supplied address (0xf8d6e0586b0a20c7).

Go back to your application and click Get NFTs again. Notice that 3 NFTs appear! Woooohoooo.

NFTs now appear on the frontend

๐Ÿ“˜ Checkpoint 4: Setup empty user Collection

Log out of the current account and login to another account. Click Get NFTs again. You will see an error appear:

error when getting NFTs

Again, this is because we haven't set up the user's account. We will do this again by clicking the Setup Collection button:

setup collection for user account

This will set up the user's account so it can receive NFTs.

Try clicking Get NFTs. You will see no NFTs appear. So let's transfer some from the other account!

๐Ÿ’พ Checkpoint 5: Transfer an NFT

๐Ÿ“” Log out of your account and go back to the Service Account. In one of the NFT boxes, copy and paste 0x179b6b1cb6755e31 and click Transfer:

transfer an NFT

This will transfer an NFT to the 0x179b6b1cb6755e31 account. Log in to that account, click Get NFTs, and you will see it has an NFT now!

๐Ÿ’พ Checkpoint 6: 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": [
  "testnet": {
    "testnet-account": [

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_STANDARD_ADDRESS to 0x631e88ae7f1d7c20
  3. PRIVATE_KEY to your private key
  4. NEXT_PUBLIC_ACCESS_NODE to https://rest-testnet.onflow.org
  5. 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!

Let's try out our DApp on testnet:

  1. Run npm run dev to start your application in a terminal.
  2. 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
  1. Click "Setup Collection" to give yourself a collection and the ability to store NFTs in your account.
  2. In a terminal, run npm run mint [THE ADDRESS OF THE ACCOUNT YOU'RE LOGGED IN TO]
  3. 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.
  4. Click "Get NFTs", and you should see all your NFTs in your account!

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 Head to your next challenge here.

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.