alchemyUserOperationSimulator

alchemyUserOperationSimulator is a middleware method you can use to easily leverage the alchemy_simulateUserOperationAssetChanges API to simulate asset changes resulting from user operation. Having this as part of your middleware stack will ensure UserOperations that fail simulation do not get sent unnecessarily.

Usage

example.ts

import {
  alchemyUserOperationSimulator,
  createAlchemyRpcClient,
} from "@alchemy/aa-alchemy";
import { createSmartAccountClient } from "@alchemy/aa-core";
import { http } from "viem";
import { sepolia } from "viem/chains";

const alchemyClient = createAlchemyRpcClient({
  transport: http("ALCHEMY_RPC_URL"),
  chain: sepolia,
});

// use Alchemy to simulate User Ops
const clientWithUserOpSimulator = createSmartAccountClient({
  ...config,
  userOperationSimulator: alchemyUserOperationSimulator(alchemyClient),
});

Returns

ClientMiddlewareFn

A ClientMiddlewareFn that will simulate a user operation using the Alchemy UserOperation Simulation API.

Parameters

client: ClientWithAlchemyMethods -- an PublicClient that is connected to Alchemy's RPC