Send Transactions

This guide explains how to send a gasless transaction, estimate fees, sign, quote, and submit a UserOperation, cap transaction fees, reuse a recent quote, use parallel nonce lanes, and use a custom paymaster token.

Send a Gasless Transaction

You can send a transaction with gas fees paid in the paymaster token using account.sendTransaction():

const result = await account.sendTransaction({
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n // 0.001 ETH in wei
})
console.log('UserOperation hash:', result.hash)
console.log('Fee paid in paymaster token:', result.fee)

Estimate Fees

You can estimate the fee for a transaction without broadcasting it using account.quoteSendTransaction():

const quote = await account.quoteSendTransaction({
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n
})
console.log('Estimated fee:', quote.fee)

Sign, Quote, and Submit a UserOperation

Use signTransaction() when a separate review or relay step needs a signed ERC-4337 v0.7 UserOperation. The method accepts one transaction, not a batch.

const tx = {
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n
}

const signedUserOperation = await account.signTransaction(tx)
const quote = await account.quoteSendTransaction(signedUserOperation)
console.log('Signed operation fee ceiling:', quote.fee)

const result = await account.sendTransaction(signedUserOperation)
console.log('UserOperation hash:', result.hash)

For signed UserOperations, sponsored mode quotes 0n. Other modes quote a 20% buffered native-gas ceiling in wei. In paymaster-token mode, that signed-operation quote is not a token-denominated paymaster charge.

Cap Transaction Fees

Set transactionMaxFee to reject non-sponsored operations newly built by sendTransaction() or signTransaction() when the estimated UserOperation fee is above your cap. A signed UserOperation passed to sendTransaction() is not checked against the cap again. Use transferMaxFee separately for token transfers.

const result = await account.sendTransaction({
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n
}, {
  transactionMaxFee: 100000
})

Reuse a Recent Quote

Default-lane, non-sponsored UserOperations built while quoting can be cached for up to 2 minutes. If you call sendTransaction() with the same transaction during that window, the account checks the current on-chain nonce before reusing a cached UserOperation. If the nonce has moved, it rebuilds before sending. Sponsored quotes do not cache a built UserOperation.

Quote methods do not resolve or reserve a nonce lane. A later send or sign using parallel or nonceKey rebuilds in that selected lane instead of reusing the quoted UserOperation.

const tx = {
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n
}

const quote = await account.quoteSendTransaction(tx)
console.log('Estimated fee:', quote.fee)

const result = await account.sendTransaction(tx)
console.log('UserOperation hash:', result.hash)

Use Parallel Nonce Lanes

Beta.14 no longer reserves sequential nonces locally. By default, operations use ERC-4337 nonce key 0; two default-lane sends started before the first is included can select the same sequence and collide.

Before using nonzero lanes, deploy the Safe with one operation and wait for its UserOperation receipt. Your bundler must support parallel nonce keys, and its per-sender mempool limits still apply.

Use parallel: true to give each independent operation a fresh random lane:

const [first, second] = await Promise.all([
  account.sendTransaction({ to: recipientA, value: 0n }, { parallel: true }),
  account.sendTransaction({ to: recipientB, value: 0n }, { parallel: true })
])

console.log(first.hash, second.hash) // UserOperation hashes

Use distinct named lanes for stable independent work streams. Strings are hashed as labels; they are not parsed as numeric keys.

const payroll = await account.sendTransaction(txA, { nonceKey: 'payroll' })
const refunds = await account.sendTransaction(txB, { nonceKey: 'refunds' })

nonceKey takes precedence over parallel. A raw numeric key must fit uint192; use a bigint above Number.MAX_SAFE_INTEGER.

signTransaction() preserves the lane chosen by the same configuration rules. In beta.14, per-call parallel and nonceKey work at runtime but are missing from the published per-call TypeScript declarations; construction-level lane configuration is typed.

Send with Custom Paymaster Token

You can override the default paymaster token for a specific transaction by passing a config object to account.sendTransaction(). This example assumes the account is already in paymaster-token mode:

const result = await account.sendTransaction({
  to: '0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6',
  value: 1000000000000000n
}, {
  paymasterToken: {
    address: '0x68749665FF8D2d112Fa859AA293F07A622782F38' // XAUT
  }
})

When switching from sponsored or native-coin mode, also set isSponsored: false and useNativeCoins: false, and provide any paymaster fields absent from the account configuration.

Next Steps

Learn how to transfer ERC-20 tokens.