How to Estimate the Gas Limits for a User Operation

To estimate the gas limits for a user operation, you need to use your Pimlico API key and make a JSON-RPC request as follows:

import { ethers } from "ethers"
 
const pimlicoApiKey = "YOUR_PIMLICO_API_KEY_HERE"
const chain = "sepolia" // find the list of supported chains at https://docs.pimlico.io/reference/bundler
const pimlicoEndpoint = `https://api.pimlico.io/v1/${chain}/rpc?apikey=${pimlicoApiKey}`
 
const userOperation = ...
const entryPoint = "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789"
 
const pimlicoProvider = new ethers.providers.StaticJsonRpcProvider(pimlicoEndpoint)
 
const estimationResult = await pimlicoProvider.send(
    "eth_estimateUserOperationGas", 
    [userOperation, entryPoint]
) 
 
const preVerificationGas = estimationResult.preVerificationGas
const verificationGasLimit = estimationResult.verificationGasLimit
const callGasLimit = estimationResult.callGasLimit

How to Bundle a User Operation Overview