generateAccessList

Generates an access list for a transaction to optimize gas usage.

Usage

example.ts

import { client } from './config'
 
const accessList = await client.generateAccessList({ 
  from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
  to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  data: '0xa9059cbb0000000000000000000000001234567890123456789012345678901234567890000000000000000000000000000000000000000000000000000000000000000a'
})
 
console.log('Access List:', accessList.accessList)
console.log('Gas Used:', accessList.gasUsed)

With Gas Comparison

// Compare gas usage with and without access list
const comparison = await client.compareAccessList()
  .call({
    from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
    to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
    data: '0xa9059cbb...'
  })
  .atBlock('latest')
  .execute()
 
console.log('Without access list:', comparison.withoutAccessList.gasUsed)
console.log('With access list:', comparison.withAccessList.gasUsed)
console.log('Gas saved:', comparison.gasSaved)
console.log('Savings:', comparison.percentageSaved.toFixed(2) + '%')

Builder Pattern

For complex access list generation.

const accessList = await client.accessList()
  .call({
    from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
    to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
    data: '0xa9059cbb...'
  })
  .atBlock('0x1234567')
  .execute()
 
// Use the access list in simulation
const result = await client.simulateCallWithAccessList(
  {
    from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
    to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
    data: '0xa9059cbb...'
  },
  accessList.accessList
)

Returns

ExtendedAccessListResponse

The access list response with helper methods.

Parameters

call

Type: TransactionCall

The transaction call to analyze.

const accessList = await client.generateAccessList({
  from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c', 
  to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  data: '0x095ea7b3...'
})

options.block (optional)

Type: string | number | bigint
Default: 'latest'

The block to generate the access list against.

const accessList = await client.generateAccessList(
  { /* transaction */ },
  { block: '0x1234567' } 
)

Access List Format

interface AccessList {
  address: string
  storageKeys: string[]
}[]

Example access list:

[
  {
    address: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
    storageKeys: [
      '0x0000000000000000000000000000000000000000000000000000000000000001',
      '0x0000000000000000000000000000000000000000000000000000000000000002'
    ]
  },
  {
    address: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
    storageKeys: []
  }
]

Gas Optimization

Access lists reduce gas costs by pre-declaring storage slots.

// EIP-2930 transaction with access list
const optimizedCall = {
  from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
  to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  data: '0xa9059cbb...',
  accessList: [
    {
      address: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
      storageKeys: ['0x0', '0x1']
    }
  ]
}
 
// Simulate with access list
const result = await client.simulateCall(optimizedCall)
console.log('Optimized gas:', result.getTotalGasUsed())

Error Handling

try {
  const accessList = await client.generateAccessList({
    from: '0x742d35Cc6634C0532925a3b844Bc9e7595f06e8c',
    to: '0xInvalidContract',
    data: '0xa9059cbb...'
  })
} catch (error) {
  if (accessList.error) {
    console.error('Access list generation failed:', accessList.error)
  }
}

Types

interface ExtendedAccessListResponse {
  accessList: AccessList
  gasUsed: string
  error?: string | null
  
  // Helper methods
  hasError(): boolean
  getGasUsed(): bigint
  getFormattedAccessList(): FormattedAccessList[]
  getTotalStorageKeys(): number
}
 
interface AccessListComparisonResult {
  withAccessList: ExtendedAccessListResponse
  withoutAccessList: ExtendedSimulationResult
  gasSaved: bigint
  percentageSaved: number
  isWorthUsing(): boolean
}