ERC20

type TokenPair struct {
    Erc20Address  string  // Hex address of ERC20 contract
    Denom         string  // Cosmos coin denomination
    Enabled       bool    // Conversion enable status
    ContractOwner Owner   // OWNER_MODULE or OWNER_EXTERNAL
}

message MsgRegisterERC20 {
    string signer = 1;
    repeated string erc20addresses = 2;
}

message MsgConvertCoin {
    Coin coin = 1;      // Amount and denom to convert
    string receiver = 2; // Hex address to receive ERC20
    string sender = 3;   // Bech32 address of sender
}

message MsgConvertERC20 {
    string contract_address = 1;  // ERC20 contract
    string amount = 2;            // Amount to convert
    string receiver = 3;          // Bech32 address
    string sender = 4;            // Hex address of sender
}

message MsgToggleConversion {
    string authority = 1;  // Must be governance account
    string token = 2;      // Address or denom
}

message MsgUpdateParams {
    string authority = 1;  // Must be governance account
    Params params = 2;     // New parameters
}

// Address derivation
address = keccak256("erc20|<denom>")[:20]

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}

interface IWERC20 is IERC20 {
    function deposit() external payable;
    function withdraw(uint256 amount) external;
}

// Automatic registration and conversion on receive
OnRecvPacket(packet) {
    // Auto-register new IBC tokens (with "ibc/" prefix)
    if !tokenPairExists && hasPrefix(denom, "ibc/") {
        RegisterERC20Extension(denom)
    }
    
    // Auto-convert to ERC20 for Ethereum addresses
    if isEthereumAddress(receiver) {
        convertToERC20(voucher, receiver)
    }
}

// Automatic conversion on acknowledgment
OnAcknowledgementPacket(packet, ack) {
    if wasConverted {
        convertBackToCosmos(refund)
    }
}

service Query {
    // Get module parameters
    rpc Params(QueryParamsRequest) returns (QueryParamsResponse);
    
    // Get all token pairs
    rpc TokenPairs(QueryTokenPairsRequest) returns (QueryTokenPairsResponse);
    
    // Get specific token pair
    rpc TokenPair(QueryTokenPairRequest) returns (QueryTokenPairResponse);
}

// Using precompiled ERC20 interface for IBC tokens
const ibcToken = new ethers.Contract(
    "0x80b5a32e4f032b2a058b4f29ec95eefeeb87adcd", // Precompile address
    ERC20_ABI,
    signer
);

// Standard ERC20 operations work seamlessly
await ibcToken.approve(dexRouter, amount);
await dexRouter.swapExactTokensForTokens(...);

// IBC transfer automatically converts to ERC20
const packet = {
    sender: "cosmos1...",
    receiver: "0x...",  // EVM address triggers conversion
    token: { denom: "uatom", amount: "1000000" }
};
// Token arrives as ERC20 in receiver's EVM account

// Convert native to ERC20
await client.signAndBroadcast(address, [
    {
        typeUrl: "/cosmos.evm.erc20.v1.MsgConvertCoin",
        value: {
            coin: { denom: "uatom", amount: "1000000" },
            receiver: "0xEthereumAddress",
            sender: "cosmos1..."
        }
    }
]);

# Check if token is registered
evmd query erc20 token-pair uatom

# Check module parameters
evmd query erc20 params

# Check account balance (both formats)
evmd query bank balances cosmos1...
evmd query vm balance 0x...