send-evm-transaction

Send EVM Transactions with MetaMask Connect

When to use

Use this skill when:

• Sending ETH transfers via eth_sendTransaction
• Calling smart contract functions by encoding data in the transaction
• Estimating gas with eth_estimateGas before sending
• Polling for transaction confirmation with eth_getTransactionReceipt
• Using the connectWith shortcut to connect and send in a single approval

Workflow

Step 1: Get the provider and connected account

import { createEVMClient, getInfuraRpcUrls } from '@metamask/connect-evm';
import type { Hex, Address } from '@metamask/connect-evm';

const client = await createEVMClient({
  dapp: { name: 'My DApp', url: window.location.href },
  api: {
    supportedNetworks: {
      ...getInfuraRpcUrls({ infuraApiKey: 'YOUR_INFURA_KEY', chainIds: ['0x1', '0x89'] }),
    },
  },
});

const { accounts } = await client.connect({ chainIds: ['0x1'] });
const provider = client.getProvider();
const from = accounts[0] as Address;

Step 2: Convert ETH to hex wei

All value fields in transactions must be hex-encoded wei. 1 ETH = 10^18 wei:

function ethToHexWei(ethAmount: string): Hex {
  const wei = BigInt(Math.round(parseFloat(ethAmount) * 1e18));
  return `0x${wei.toString(16)}` as Hex;
}

// Examples
ethToHexWei('0.01');   // '0x2386f26fc10000'
ethToHexWei('0.001');  // '0x38d7ea4c68000'
ethToHexWei('1');      // '0xde0b6b3a7640000'

Step 3: Send an ETH transfer

Build the transaction params and call eth_sendTransaction:

const txParams = {
  from: from,
  to: '0xRecipientAddress' as Address,
  value: ethToHexWei('0.01'),
};

try {
  const txHash = await provider.request({
    method: 'eth_sendTransaction',
    params: [txParams],
  }) as Hex;

  console.log('Transaction hash:', txHash);
} catch (err: any) {
  if (err.code === 4001) {
    console.log('User rejected the transaction');
    return;
  }
  if (err.code === -32002) {
    console.log('A transaction request is already pending');
    return;
  }
  throw err;
}