Burn Access Key Witness

Burns a key-authorization witness, invalidating any authorization bound to it before it is submitted onchain.

Usage

import { client } from './viem.config'
 
const { witness, receipt } = await client.accessKey.burnWitnessSync({
  witness: '0x0000000000000000000000000000000000000000000000000000000000000001',
})
 
console.log('Burned witness:', witness)
console.log('Transaction hash:', receipt.transactionHash)
Burned witness: 0x0000000000000000000000000000000000000000000000000000000000000001
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 accessKey.burnWitness action and wait for inclusion manually:

import { Actions } from 'viem/tempo'
import { client } from './viem.config'
 
const hash = await client.accessKey.burnWitness({
  witness: '0x0000000000000000000000000000000000000000000000000000000000000001',
})
const receipt = await client.transaction.waitForReceipt({ hash }).receipt
 
const { args } = Actions.accessKey.burnWitness.extractEvent(receipt.logs)

Recipes

Cancel an Issued Authorization Before First Use

Combine a witness signed via accessKey.signAuthorization with burnWitness to cancel an authorization you handed out before it is submitted onchain.

import { P256 } from 'viem/utils'
import { Account } from 'viem/tempo'
import { client } from './viem.config'
 
const account = Account.fromSecp256k1('0x...')
const accessKey = Account.fromP256(P256.randomPrivateKey(), {
  access: account,
})
 
// Issue a revocable authorization bound to a witness.
const witness =
  '0x9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658'
const keyAuthorization = await client.accessKey.signAuthorization({
  accessKey,
  witness,
})
 
// The user abandons checkout: burn the witness so the
// authorization can never activate.
const { receipt } = await client.accessKey.burnWitnessSync({
  witness,
})

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

Make a Cancel Endpoint Idempotent

Check accessKey.isWitnessBurned first so repeated cancel requests skip the transaction once the witness is burned.

import { client } from './viem.config'
 
const witness =
  '0x9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658'
 
const burned = await client.accessKey.isWitnessBurned({ witness })
if (!burned)
  await client.accessKey.burnWitnessSync({ witness })

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

Return Value

type ReturnType = {
  /** Account the witness was burned on. */
  account: Address
  /** The burned witness. */
  witness: Hex
  /** Transaction receipt. */
  receipt: TransactionReceipt
}

The burned witness details and the transaction receipt.

Parameters

witness

• Type: Hex

The 32-byte witness to burn.

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.