Cardano NFT Minter

This is a create react app and can be launched by running npm install and npm start from the root directory

Purpose

To mint NFTs on the Cardano Blockchain using the cardano-serialization-lib which means it can be built in the browser, without the need to interact with smart contracts

Workflow minting in Browser - work in progress

• Select image to upload from user's computer
• The app loads the image onto IPFS
• The app generates ...

Steps to mint an NFT using cardano-cli

Remastered from Cardano Portal

• Register on Pinata IPFS gateway , or similar and upload your image
• You will receive a code where your image is now hosted on IPFS
• Example code: https://ipfs.io/ipfs/QmPanjt7mQWKmySWddGSvx8iyRDWNSGVn4W3KqHGcE4KiU

realtokenname="GUINCHO"
tokenname="4755494e43484f"
#tokenname=$(echo -n $realtokenname | xxd -b -ps -c 80 | tr -d '\n')
tokenamount="1"
fee="0"
output="0"
ipfs_hash="QmPanjt7mQWKmySWddGSvx8iyRDWNSGVn4W3KqHGcE4KiU"

Generate keys

cardano-cli address key-gen --verification-key-file payment.vkey --signing-key-file payment.skey
cardano-cli address build --payment-verification-key-file payment.vkey --out-file payment.addr --testnet-magic 1097911063
address=$(cat payment.addr)

Fund the address

Send the funds to the address.addr.

You can get testADA from the FAUCET

Check that funds have been received by running the following command

cardano-cli query utxo --address $address --testnet-magic 1097911063

Export protocol parameters

cardano-cli query protocol-parameters --testnet-magic 1097911063 --out-file protocol.json

Create policyId

cardano-cli address key-gen \
    --verification-key-file policy.vkey \
    --signing-key-file policy.skey

Find the current slot and add 43200 to it (so that the NFT can only be minted between now and the next 43 200 seconds, or about 12 hours)

cardano-cli query tip --testnet-magic 1097911063
slotnumber=<slot number>

Create the policy.script file

echo "{" >> policy.script
echo "  \"type\": \"all\"," >> policy.script 
echo "  \"scripts\":" >> policy.script 
echo "  [" >> policy.script 
echo "   {" >> policy.script 
echo "     \"type\": \"before\"," >> policy.script 
echo "     \"slot\": $(expr $slotnumber + 43200)" >> policy.script
echo "   }," >> policy.script 
echo "   {" >> policy.script
echo "     \"type\": \"sig\"," >> policy.script 
echo "     \"keyHash\": \"$(cardano-cli address key-hash --payment-verification-key-file policy.vkey)\"" >> policy.script 
echo "   }" >> policy.script
echo "  ]" >> policy.script 
echo "}" >> policy.script

script="policy.script"

cardano-cli transaction policyid --script-file policy.script > policyID

Create Metadata

echo "{" >> metadata.json
echo "  \"721\": {" >> metadata.json 
echo "    \"$(cat policyID)\": {" >> metadata.json 
echo "      \"$(echo $realtokenname)\": {" >> metadata.json
echo "        \"description\": \"Guincho in Cascais, Portugal, overlooking the Sintra mountain\"," >> metadata.json
echo "        \"name\": \"Guincho NFT\"," >> metadata.json
echo "        \"id\": \"1\"," >> metadata.json
echo "        \"image\": \"ipfs://$(echo $ipfs_hash)\"" >> metadata.json
echo "      }" >> metadata.json
echo "    }" >> metadata.json 
echo "  }" >> metadata.json 
echo "}" >> metadata.json

Build the transaction

Check that you have some ADA balance at your address

cardano-cli query utxo --address $address --testnet-magic 1097911063

Set the TxHash, TxIx and Amount to variables:

txhash="1d41be2e9e3fbdb658871a4c2673883929b3e439f2f30bca4d5b3646854ede66"
txix="0"
funds="10000000"
policyid=$(cat policyID)
output=1400000

check that all the variables have been set

echo $fee
echo $address
echo $output
echo $tokenamount
echo $policyid
echo $tokenname
echo $slotnumber
echo $script

build the transaction

cardano-cli transaction build \
--testnet-magic 1097911063 \
--alonzo-era \
--tx-in $txhash#$txix \
--tx-out $address+$output+"$tokenamount $policyid.$tokenname" \
--change-address $address \
--mint="$tokenamount $policyid.$tokenname" \
--minting-script-file $script \
--metadata-json-file metadata.json  \
--invalid-hereafter $(expr $slotnumber + 43200) \
--witness-override 2 \
--out-file matx.raw

if the transaction gives an error and says something like Minimum required UTxO: Lovelace 1448244, then change your output amount to that larger number After successfully running it should show you the estimated transaction fee Estimated transaction fee: Lovelace 187941

Sign the transaction

cardano-cli transaction sign  \
--signing-key-file payment.skey  \
--signing-key-file policy.skey  \
--testnet-magic 1097911063 \
--tx-body-file matx.raw  \
--out-file matx.signed

Submit the transaction

cardano-cli transaction submit --tx-file matx.signed --testnet-magic 1097911063

If you get Transaction successfully submitted. then it means that everything worked as planned

Check that you NFT has been minted

If you minted on the mainnet then search for your address at pool.pm If you minted on the testnet then search for the policyId at https://testnet.adatools.io/nft