CustomPrecompile

CustomPrecompile: Exclude<Exclude<Parameters<typeof Evm["create"]>[0], undefined>["customPrecompiles"], undefined>[number]

Custom precompiles allow you to run arbitrary JavaScript code in the EVM

Example

import { createMemoryClient } from 'tevm'
import { type CustomPrecompile } from 'tevm/evm'
import { definePrecompile, defineCall } from 'tevm'
import { createContract } from 'tevm/contract'

const precompileContract = createContract({
  name: 'Precompile',
  humanReadableAbi: [
    'function cwd(string) returns (string)',
  ],
})
const customPrecompiles: CustomPrecompile = definePrecompile({
  contract: precompileContract,
  call: defineCall(precompileContract.abi, {
    cwd: async ({ args }) => {
      return {
        returnValue: process.cwd(),
        executionGasUsed: 0n,
      }
    },
  }),
})

const memoryClient = createMemoryClient({ customPrecompiles: [customPrecompiles] })

See

• Scripting guide
• definePrecompile
• MemoryClient

Defined in

packages/evm/src/CustomPrecompile.ts:41