Create a Foundry

caution

This method is now obsolete, use the new createNativeTokenFoundry method instead.

About Foundries

The Stardust update allows you to create your own native tokens. Native tokens are minted by a Foundry. The Foundry allows you to specify your native token's maximum supply once and change the circulating supply. This guide will show you how to create an L1 foundry using a L2 smart contract.

Example Code

Ownership

You might want to look into making the function ownable with, for example, OpenZeppelin so only owners of the contract can call certain functionalities of your contract.

1. Check the Storage Deposit

Check if the amount paid to the contract is the same as the required storage deposit and set the allowance.

require(msg.value == _storageDeposit*(10**12), "Please send exact funds to pay for storage deposit");
ISCAssets memory allowance;
allowance.baseTokens = _storageDeposit;

Payable

Instead of making the function payable, you could let the contract pay for the storage deposit. If so, you will need to change the require statement to check if the contract's balance has enough funds:

require(address(this).balance > _storageDeposit);

2. Define the Token Scheme

Define the NativeTokenScheme by specifying its mintedTokens, meltedTokens and maximumSupply:

NativeTokenScheme memory nativeTokenScheme = NativeTokenScheme({
    mintedTokens: _mintedTokens,
    meltedTokens: _meltedTokens,
    maximumSupply: _maximumSupply
});

3. Create the Foundry

Create the foundry by calling the ISC.accounts.foundryCreateNew(nativeTokenScheme, allowance) function:

uint32 foundrySN = ISC.accounts.foundryCreateNew(nativeTokenScheme, allowance);

Full Example Code

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@iota/iscmagic/ISC.sol";

contract CreateFoundry {
    event CreatedFoundry(uint32 foundrySN);

    function createFoundry(uint _mintedTokens, uint _meltedTokens, uint _maximumSupply, uint64 _storageDeposit) public payable {
        require(msg.value == _storageDeposit*(10**12), "Please send exact funds to pay for storage deposit");
        ISCAssets memory allowance;
        allowance.baseTokens = _storageDeposit;
        NativeTokenScheme memory nativeTokenScheme = NativeTokenScheme({
            mintedTokens: _mintedTokens,
            meltedTokens: _meltedTokens,
            maximumSupply: _maximumSupply
        });
        uint32 foundrySN = ISC.accounts.foundryCreateNew(nativeTokenScheme, allowance);
        emit CreatedFoundry(foundrySN);
    }
}