Bun example API

Package: @tevm/example-bun · Source: apps/bun

readContract.ts

client

const client: MemoryClient

A Tevm memory client forked from process.env.RPC_URL, falling back to a local node at http://localhost:8545. State is fetched lazily from the fork transport, so reads resolve against real chain state without syncing a node.

import { client } from './readContract.js'
 
const blockNumber = await client.getBlockNumber()

ReadContractOptions

type ReadContractOptions = {
  /** Contract address to read from. Defaults to the zero address. */
  address?: Address
  /** Account passed as the `balanceOf` argument. Defaults to the zero address. */
  account?: Address
  /** ABI to decode against. Defaults to the ERC20 ABI shipped with `tevm/contract`. */
  abi?: typeof ERC20.abi
  /** Function to call. Only `balanceOf` is supported by this example. */
  functionName?: 'balanceOf'
}

Every field is optional; the defaults read balanceOf(0x0…0) on the zero address using the built-in ERC20 ABI.

readContract

function readContract(options?: ReadContractOptions): Promise<bigint>

Reads an ERC20 balance through the forked memory client.

Returns — the decoded balance as a bigint.

Throws — if the fork transport is unreachable, or if the address does not expose an ERC20-compatible balanceOf (the call reverts and viem throws a ContractFunctionExecutionError).

import { readContract } from './readContract.js'
 
const balance = await readContract({
  address: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  account: '0x55FE002aefF02F77364de339a1292923A15844B8',
})
console.log(balance) // 1234567890n

plugins.ts

Side-effecting module. Registers bunPluginTevm({}) with Bun's plugin registry so .sol imports resolve. Exports nothing; it must be listed in bunfig.toml under both preload and [test].preload.

ExampleContract.sol

contract ExampleContract is ERC721 — the wagmi mint example. Public surface:

Everything ERC721 and ERC721Enumerable provides is inherited from OpenZeppelin.