How can I mint a Hedera token that is not owned by the contract I am using to mint it? - solidity

Question

I want to mint a Hedera Token with a smart contract. This token is not owned by the smart contract I am writing. I have been told on the Discord to 'put the private key in the contract' but this is not very specific and feels weird. The mintToken function provided in the Hedera Token Service takes as parameter:
an address
an amount
some metadata in the case of NFTs.

Answer 1

It's not impossible to mint a token made of a smart contract with HederaTokenService.
You may use a smart contract to make a token on hedera like ERC-20 or ERC-721, they works but they are not recognized as tokens in hedera network.
You have to use HederaTokenService to make a token on hedera.
You can use a smart contract using HederaTokenService interface(its address is 0x167) or transactions like below.
You seems using HederaTokenService.sol.
The second parameter only has meaning when you mint a fungible token.
And the second parameter only has meaning when you mint a non-funtible token.
You can create a fungible token and mint like this.
IHederaTokenService.TokenKey[]
memory keys = new IHederaTokenService.TokenKey[](1);
// Set this contract as supply
keys[0] = getSingleKey(
KeyType.SUPPLY,
KeyValueType.CONTRACT_ID,
address(this)
);
IHederaTokenService.HederaToken memory token;
token.name = _name;
token.symbol = _symbol;
token.treasury = address(this);
token.memo = _memo;
token.tokenSupplyType = true; // set supply to FINITE
token.maxSupply = _maxSupply;
token.freezeDefault = false;
token.tokenKeys = keys;
token.expiry = createAutoRenewExpiry(address(this), _autoRenewPeriod); // Contract automatically renew by himself
(int256 responseCode, address createdToken) = HederaTokenService
.createFungibleToken(token, 0, _decimals);
if (responseCode != HederaResponseCodes.SUCCESS) {
revert("Failed to create fungible token");
}
tokenAddress = createdToken;
(int256 response, uint64 newSupply, ) = HederaTokenService.mintToken(
tokenAddress,
uint64(amount),
new bytes[](0)
);
Or a Non-fungible token like this.
IHederaTokenService.TokenKey[]
memory keys = new IHederaTokenService.TokenKey[](2);
// Set this contract as supply
keys[0] = getSingleKey(
KeyType.SUPPLY,
KeyValueType.CONTRACT_ID,
address(this)
);
keys[1] = getSingleKey(
KeyType.PAUSE,
KeyValueType.CONTRACT_ID,
address(this)
);
IHederaTokenService.HederaToken memory token;
token.name = _name;
token.symbol = _symbol;
token.treasury = address(this);
token.memo = _memo;
token.tokenSupplyType = true; // set supply to FINITE
token.maxSupply = int64(int256(_maxSupply));
token.freezeDefault = false;
token.tokenKeys = keys;
token.expiry = createAutoRenewExpiry(address(this), _autoRenewPeriod); // Contract automatically renew by himself
(int256 responseCode, address createdToken) = HederaTokenService
.createNonFungibleToken(token);
if (responseCode != HederaResponseCodes.SUCCESS) {
revert("Failed to create non-fungible token");
}
tokenAddress = createdToken;
(int256 response, uint64 newSupply, ) = HederaTokenService.mintToken(
tokenAddress,
uint64(amount),
new bytes[](0)
);
(int256 response, , int64[] memory serialNumbers) = HederaTokenService
.mintToken(tokenAddress, 0, metadata);
Here is a code of using transactions.
Hope it will help you.
const {
Client,
AccountId,
AccountBalanceQuery,
ContractExecuteTransaction,
ContractFunctionParameters,
ContractCallQuery,
TokenCreateTransaction,
Hbar,
HbarUnit,
TransactionRecord,
TokenSupplyType,
TokenType,
PrivateKey,
AccountCreateTransaction,
TokenId,
TokenMintTransaction,
TokenAssociateTransaction,
TokenDissociateTransaction,
TransferTransaction,
} = require("#hashgraph/sdk");
// Allow access to ourenv file variables
require("dotenv").config();
const print = require("./utils.js").print;
// Grab your account ID and private key from the .env file
const operatorAccountId = AccountId.fromString(process.env.MY_ACCOUNT_ID);
const operatorPrivateKey = PrivateKey.fromString(process.env.MY_PRIVATE_KEY);
const operatorPublicKey = operatorPrivateKey.publicKey;
const treasuryId = AccountId.fromString(process.env.TREASURY_ID);
const treasuryKey = PrivateKey.fromString(process.env.TREASURY_PVKEY);
const aliceId = AccountId.fromString(process.env.ALICE_ID);
const aliceKey = PrivateKey.fromString(process.env.ALICE_PVKEY);
const supplyKey = PrivateKey.fromString(process.env.SUPPLY_PVKEY);
const tokenId = TokenId.fromString("0.0.*");
// If we weren't able to grab it, we should throw a new error
if (operatorPrivateKey == null || operatorAccountId == null) {
throw new Error(
"environment variables MY_ACCOUNT_ID and MY_PRIVATE_KEY must be present"
);
}
// Create our connection to the Hedera network
// The Hedera JS SDK makes this really easy!
const client = Client.forTestnet();
// Set your client account ID and private key used to pay for transaction fees and sign transactions
client.setOperator(operatorAccountId, operatorPrivateKey);
async function printBalance(accountAlias, accountId) {
var currentBalance = await new AccountBalanceQuery()
.setAccountId(accountId.toString())
.execute(client);
console.log(
`Balance of ${accountAlias} (accountId ${accountId}): ${currentBalance.toString()}`
);
}
async function queryContract() {
const tx = new ContractCallQuery()
.setGas(300000)
.setContractId(tokenId.toString())
.setFunction(
"tokenURI",
new ContractFunctionParameters().addUint256(12)
// .addString("Golden")
);
// .setQueryPayment(Hbar.fromTinybars(300000));
const contractFunctionResult = await tx.execute(client);
console.log();
const ret_0 = contractFunctionResult.getString(0);
console.log(`return value :>> ${ret_0.toString()}`);
}
async function generateKey() {
const privateKey = await PrivateKey.generateED25519Async();
console.log(
`New key generated.\nPublic Key is ${privateKey.publicKey}\nPrivateKey is ${privateKey}`
);
return privateKey;
}
async function createAccount() {
const privateKey = await generateKey();
const transaction = new AccountCreateTransaction()
.setKey(privateKey.publicKey)
.setInitialBalance(new Hbar(1000));
//Sign the transaction with the client operator private key and submit to a Hedera network
const txResponse = await transaction.execute(client);
//Request the receipt of the transaction
const receipt = await txResponse.getReceipt(client);
//Get the account ID
const newAccountId = receipt.accountId;
console.log("The new account ID is " + newAccountId);
}
async function writeContract() {
const tx = new ContractExecuteTransaction()
.setContractId(contractId)
.setGas(300000) // Increase if revert
.setPayableAmount(Hbar.from(1.00000001)) // Increase if revert
.setFunction("pay", new ContractFunctionParameters().addString("Donate"));
const txRes = await tx.execute(client);
print("txResponse", txRes);
const receipt = await txRes.getReceipt(client);
print("recepit", receipt);
const txRec = await txRes.getRecord(client);
print("txRecord", txRec);
const value = txRec.contractFunctionResult.getUint256(0);
console.log(`First return value is: ${value.toString()}`);
const ret_0 = txRec.contractFunctionResult.getString(1);
console.log(`second return value is: ${ret_0.toString()}`);
// console.log(`First return value is: ${AccountId.fromSolidityAddress(ret_0)}`);
}
async function createToken() {
const transaction = await new TokenCreateTransaction()
.setTokenName("My Token")
.setTokenSymbol("MYT")
.setTokenType(TokenType.NonFungibleUnique)
.setDecimals(0)
.setInitialSupply(0)
.setTreasuryAccountId(treasuryId)
.setSupplyType(TokenSupplyType.Finite)
.setMaxSupply(1000)
.setSupplyKey(supplyKey)
.freezeWith(client);
//Sign the transaction with the token adminKey and the token treasury account private key
const signTx = await transaction.sign(treasuryKey);
//Sign the transaction with the client operator private key and submit to a Hedera network
const txRes = await signTx.execute(client);
print("txResponse", txRes);
const receipt = await txRes.getReceipt(client);
print("recepit", receipt);
const txRec = await txRes.getRecord(client);
print("txRecord", txRec);
//Get the token ID
let tokenId = receipt.tokenId;
//Log the token ID
console.log(`- Created NFT with Token ID: ${tokenId} \n`);
}
async function mintToken() {
// Mint new NFT
let mintTx = await new TokenMintTransaction()
.setTokenId(tokenId)
.setMetadata([
Buffer.from(
"A METADATA LINK"
),
])
.freezeWith(client);
//Sign the transaction with the supply key
let mintTxSign = await mintTx.sign(supplyKey);
print("Singed Tx", mintTxSign);
//Submit the transaction to a Hedera network
let minttxRes = await mintTxSign.execute(client);
print("Tx Response", minttxRes);
//Get the transaction receipt
let mintRx = await minttxRes.getReceipt(client);
print("Tx Receipt", mintRx);
//Get the transaction record
let mintRec = await minttxRes.getRecord(client);
print("Tx Record", mintRec);
//Log the serial number
console.log(
`- Created NFT ${tokenId} with serial: ${mintRx.serials[0].low} \n`
);
}
async function associateToken(tokenIds) {
//Create the associate transaction and sign with Alice's key
let tx = await new TokenAssociateTransaction()
.setAccountId(aliceId)
.setTokenIds(tokenIds)
.freezeWith(client)
.sign(aliceKey);
//Submit the transaction to a Hedera network
let txRes = await tx.execute(client);
print("Tx Response", txRes);
//Get the transaction receipt
let txRx = await txRes.getReceipt(client);
print("Tx Receipt", txRx);
//Get the transaction record
let txRec = await txRes.getRecord(client);
print("Tx Record", txRec);
//Confirm the transaction was successful
console.log(`- NFT association with Alice's account: ${txRx.status}\n`);
}
async function dissociateToken(tokenIds) {
//Create the associate transaction and sign with Alice's key
let tx = await new TokenDissociateTransaction()
.setAccountId(operatorAccountId)
.setTokenIds(tokenIds)
.freezeWith(client)
.sign(aliceKey);
//Submit the transaction to a Hedera network
let txRes = await tx.execute(client);
print("Tx Response", txRes);
//Get the transaction receipt
let txRx = await txRes.getReceipt(client);
print("Tx Receipt", txRx);
//Get the transaction record
let txRec = await txRes.getRecord(client);
print("Tx Record", txRec);
//Confirm the transaction was successful
console.log(`- NFT association with Alice's account: ${txRx.status}\n`);
}
async function transferToken() {
// Check the balance before the transfer for the treasury account
var balanceCheckTx = await new AccountBalanceQuery()
.setAccountId(treasuryId)
.execute(client);
console.log(
`- Treasury balance: ${balanceCheckTx.tokens._map.get(
tokenId.toString()
)} NFTs of ID ${tokenId}`
);
// Check the balance before the transfer for Alice's account
var balanceCheckTx = await new AccountBalanceQuery()
.setAccountId(aliceId)
.execute(client);
console.log(
`- Alice's balance: ${balanceCheckTx.tokens._map.get(
tokenId.toString()
)} NFTs of ID ${tokenId}`
);
// Transfer the NFT from treasury to Alice
// Sign with the treasury key to authorize the transfer
let tokenTransferTx = await new TransferTransaction()
.addNftTransfer(tokenId, 2 /*SN*/, treasuryId, aliceId)
.freezeWith(client)
.sign(treasuryKey);
let tokenTransferSubmit = await tokenTransferTx.execute(client);
print("Tx Response", tokenTransferSubmit);
let tokenTransferRx = await tokenTransferSubmit.getReceipt(client);
print("Tx Receipt", tokenTransferRx);
let tokenTransferRec = await tokenTransferSubmit.getRecord(client);
print("Tx Record", tokenTransferRec);
console.log(
`\n- NFT transfer from Treasury to Alice: ${tokenTransferRx.status} \n`
);
// Check the balance of the treasury account after the transfer
var balanceCheckTx = await new AccountBalanceQuery()
.setAccountId(treasuryId)
.execute(client);
console.log(
`- Treasury balance: ${balanceCheckTx.tokens._map.get(
tokenId.toString()
)} NFTs of ID ${tokenId}`
);
// Check the balance of Alice's account after the transfer
var balanceCheckTx = await new AccountBalanceQuery()
.setAccountId(aliceId)
.execute(client);
console.log(
`- Alice's balance: ${balanceCheckTx.tokens._map.get(
tokenId.toString()
)} NFTs of ID ${tokenId}`
);
}
// Hedera is an asynchronous environment :)
(async function () {
await printBalance("Operator", operatorAccountId);
try {
// await printBalance("Treasury", treasuryId);
// await createAccount();
// await generateKey();
// await createToken();
// await mintToken();
// await associateToken();
// await dissociateToken();
// await transferToken();
// await queryContract();
// await writeContract();
// await printBalance("Treasury", treasuryId);
} catch (err) {
console.error(err);
}
await printBalance("Operator", operatorAccountId);
process.exit();
})();