LP-3022: LRC-20 Mintable Extension

Abstract

This extension adds minting capability to LRC-20 tokens, enabling designated accounts to generate new tokens within defined constraints.

Motivation

Mintable tokens are essential for protocols requiring dynamic supply management, such as stablecoins, reward distributions, and governance tokens.

Specification

interface IERC20Mintable {
    /**
     * @dev Creates `amount` new tokens for `to`, increasing total supply.
     */
    function mint(address to, uint256 amount) external;
}

Rationale

Token minting is a core extension for applications needing controlled supply issuance. This interface aligns with the common OpenZeppelin pattern for mintable tokens.

Backwards Compatibility

This is a backwards-compatible, additive extension to LRC-20. Core token operations remain unaffected.

Test Cases

Standard tests should cover:

Minting new tokens to specified addresses
Total supply increase consistency
Access control and permission checks

Reference Implementation

See the IERC20Mintable interface in the standard repository:

/standard/src/interfaces/IERC20Mintable.sol

Implementation

LRC-20 Mintable Token Contracts

Location: ~/work/lux/standard/src/tokens/

Core Contracts:

LRC20.sol - Base LRC-20 implementation
ERC20Mintable.sol - Mintable extension
ERC20Burnable.sol - Burnable extension
Ownable.sol - Access control for minting

Minting Implementation:

// Example from ERC20Mintable.sol
function mint(address to, uint256 amount) external onlyMinter {
    require(to != address(0), "Invalid recipient");
    require(amount > 0, "Mint amount must be positive");

    _totalSupply += amount;
    _balances[to] += amount;

    emit Transfer(address(0), to, amount);
}

Testing:

cd ~/work/lux/standard
forge test --match-contract ERC20MintableTest
forge coverage --match-contract ERC20Mintable

Gas Costs

Operation	Gas Cost	Notes
mint	~50,000	ERC20 balance update + event
setMinter	~20,000	Access control change
renounceMinter	~5,000	Self-revoke minting rights

Security Considerations

Restrict minting to authorized roles to prevent inflation attacks.
Implement supply caps or governance checks as needed.
Use AccessControl or Ownable patterns for role management.
Emit events for all mint operations for auditability.

LRC-20 Mintable Extension