ERC-20 Token Transfer

import { Abi } from '@tevm/voltaire/Abi';
import { Hex } from '@tevm/voltaire/Hex';
import { Address } from '@tevm/voltaire/Address';

// ERC-20 transfer function ABI
const erc20Abi = Abi([
  {
    type: "function",
    name: "transfer",
    stateMutability: "nonpayable",
    inputs: [
      { type: "address", name: "to" },
      { type: "uint256", name: "amount" }
    ],
    outputs: [{ type: "bool", name: "" }]
  }
]);

// Encode transfer(address,uint256) function call
const recipient = "0x742d35cc6634c0532925a3b844bc9e7595f251e3";
const amount = 1000000000000000000n; // 1 token (18 decimals)

const calldata = erc20Abi.encode("transfer", [recipient, amount]);
// Result: 0xa9059cbb... (4-byte selector + ABI-encoded params)

// The calldata can be used in a transaction
const tx = {
  to: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC contract
  data: Hex.fromBytes(calldata),
  value: 0n
};

// Decode the calldata to verify
const decoded = erc20Abi.decodeData(calldata);

// decoded.name = "transfer"
// decoded.params = ["0x742d35cc6634c0532925a3b844bc9e7595f251e3", 1000000000000000000n]

const transferFn = erc20Abi.getFunction("transfer");
const selector = Abi.Function.getSelector(transferFn);
// 0xa9059cbb = keccak256("transfer(address,uint256)")[0:4]

const signature = Abi.Function.getSignature(transferFn);
// "transfer(address,uint256)"

import { Secp256k1 } from '@tevm/voltaire/Secp256k1';
import { Transaction } from '@tevm/voltaire/Transaction';
import { Keccak256 } from '@tevm/voltaire/Keccak256';

// Build unsigned EIP-1559 transaction
const unsignedTx = Transaction.fromEIP1559({
  chainId: 1n,
  nonce: 0n,
  maxPriorityFeePerGas: 1000000000n,
  maxFeePerGas: 50000000000n,
  gasLimit: 100000n,
  to: Address.from("0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"),
  value: 0n,
  data: calldata
});

// Sign the transaction
const privateKey = Hex.toBytes("0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80");
const serialized = Transaction.serialize(unsignedTx);
const hash = Keccak256(serialized);
const signature = Secp256k1.sign(hash, privateKey);

// Create signed transaction
const signedTx = Transaction.addSignature(unsignedTx, signature);
const rawTx = Transaction.serialize(signedTx);
// Ready to broadcast via eth_sendRawTransaction