Set User Fee Token

Sets the calling account's default fee token.

Usage

import { client } from './viem.config'
 
const { receipt } = await client.fee.setUserTokenSync({
  token: '0x20c0000000000000000000000000000000000001',
})
 
console.log('Transaction hash:', receipt.transactionHash)
Transaction hash: 0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef

import { Account, Client } from 'viem/tempo'
 
export const client = Client.create({
  account: Account.fromSecp256k1('0x...'),
})

Asynchronous Usage

The examples above use a *Sync variant of the action, that will wait for the transaction to be included before returning.

If you are optimizing for performance, you should use the non-sync fee.setUserToken action and wait for inclusion manually:

import { Actions } from 'viem/tempo'
import { client } from './viem.config'
 
const hash = await client.fee.setUserToken({
  token: '0x20c0000000000000000000000000000000000001',
})
const receipt = await client.transaction.waitForReceipt({ hash }).receipt
 
const { args } = Actions.fee.setUserToken.extractEvent(receipt.logs)

Recipes

Validate a Token Before Saving It

Combine fee.validateToken with setUserToken to reject paused or non-USD tokens before persisting a user's choice.

import { client } from './viem.config'
 
const alphaUsd = '0x20c0000000000000000000000000000000000001'
 
const { address } = await client.fee.validateToken({ token: alphaUsd })
 
const { receipt } = await client.fee.setUserTokenSync({ token: address })

import { Account, Client } from 'viem/tempo'
 
export const client = Client.create({
  account: Account.fromSecp256k1('0x...'),
})

Onboard a User Who Only Holds One Stablecoin

Pass feeToken on the update itself so an account holding only the new token can pay for the switch, with no pathUSD required.

import { client } from './viem.config'
 
const alphaUsd = '0x20c0000000000000000000000000000000000001'
 
const { receipt } = await client.fee.setUserTokenSync({
  feeToken: alphaUsd,
  token: alphaUsd,
})

import { Account, Client } from 'viem/tempo'
 
export const client = Client.create({
  account: Account.fromSecp256k1('0x...'),
})

Set the Preference of a Payout Account

Pass account to update an account other than the Client's default, such as a payout account a backend operates.

import { Account } from 'viem/tempo'
import { client } from './viem.config'
 
const payoutAccount = Account.fromSecp256k1('0x...')
 
const { receipt } = await client.fee.setUserTokenSync({
  account: payoutAccount,
  token: '0x20c0000000000000000000000000000000000001',
})

import { Account, Client } from 'viem/tempo'
 
export const client = Client.create({
  account: Account.fromSecp256k1('0x...'),
})

Return Value

type ReturnType = {
  /** Token set as the account's default fee token. */
  token: Address
  /** Account the fee token was set for. */
  user: Address
  /** Transaction receipt. */
  receipt: TransactionReceipt
}

Parameters

token

• Type: Address

Token address to set as the default fee token.

account (optional)

• Type: Account | Address

Account that will be used to send the transaction.

feePayer (optional)

• Type: Account | boolean

Fee payer for the transaction (TIP-1 gas sponsorship).

Pass true to defer the fee token to an external fee payer (e.g. a relay), or a local Account to co-sign the transaction as the fee payer.

feeToken (optional)

• Type: Address | bigint

Fee token for the transaction.

Can be an unpaused USD-denominated TIP-20 token address or ID.

gas (optional)

• Type: bigint

Gas limit for the transaction.

keyAuthorization (optional)

• Type: KeyAuthorization

Signed key authorization to include with the transaction, authorizing an access key to act for the sending account.

maxFeePerGas (optional)

• Type: bigint

Max fee per gas for the transaction.

maxPriorityFeePerGas (optional)

• Type: bigint

Max priority fee per gas for the transaction.

nonce (optional)

• Type: number

Nonce for the transaction.

nonceKey (optional)

• Type: 'expiring' | 'random' | bigint

Nonce key for the transaction (TIP-1009 2D nonces).

Use 'expiring' to select an expiring nonce, which enables concurrent transaction submission without nonce ordering. Use 'random' to select a random key.

throwOnReceiptRevert (optional)

• Type: boolean
• Default: true

Whether a Sync action throws when the receipt reports a revert.

validAfter (optional)

• Type: number

Unix timestamp after which the transaction can be included.

validBefore (optional)

• Type: number

Unix timestamp before which the transaction must be included.