Gas Estimation

Estimate gas costs for transactions before execution to optimize costs and ensure sufficient funds.

Overview

Gas estimation helps you:

Predict transaction costs
Optimize gas usage
Ensure wallet has sufficient funds
Set appropriate gas prices

Basic Gas Estimation

// Using API HTTP (fetch)
const response = await fetch('https://api.msa.omnes.tech/estimateGas', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    operations: [{
      walletCustody: 1, // ECDSA_VALIDATOR
      salt: 'user@example.com',
      to: '0x097d4Aed5924e2172451973153Fc0e03407eD1F9',
      funcSignature: 'transfer(address,uint256)',
      funcParams: ['0xRecipient...', '1000000']
    }],
    settings: {
      rpc: 'https://rpc-amoy.polygon.technology/',
      factory: '0xb09Fd1134553a43A3E02182a6B04F4dEBa7476F4',
      validator: '0x9bD18Da66990F80d598dE02d5143dC9A4422eC3a',
      entryPoint: '0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789',
      beaconAdminAddress: '0x99Ee7725D6a8f691d8B375e0aD33d1Aff2236618'
    }
  })
});

const gasEstimate = await response.json();

console.log('Estimated gas limit:', gasEstimate.gasLimit);
console.log('Gas price:', gasEstimate.gasPrice);
console.log('Total cost:', gasEstimate.totalCost);

import requests

def estimate_gas():
    url = "https://api.msa.omnes.tech/estimateGas"
    
    payload = {
        "operations": [{
            "walletCustody": 1,
            "salt": "user@example.com",
            "to": "0x097d4Aed5924e2172451973153Fc0e03407eD1F9",
            "funcSignature": "transfer(address,uint256)",
            "funcParams": ["0xRecipient...", "1000000"]
        }],
        "settings": {
            "rpc": "https://rpc-amoy.polygon.technology/",
            "factory": "0xb09Fd1134553a43A3E02182a6B04F4dEBa7476F4",
            "validator": "0x9bD18Da66990F80d598dE02d5143dC9A4422eC3a",
            "entryPoint": "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789",
            "beaconAdminAddress": "0x99Ee7725D6a8f691d8B375e0aD33d1Aff2236618"
        }
    }
    
    response = requests.post(url, json=payload)
    return response.json()

estimate_gas()

curl -X POST "https://api.msa.omnes.tech/estimateGas" \
  -H "Content-Type: application/json" \
  -d '{
    "operations": [{
      "walletCustody": 1,
      "salt": "user@example.com",
      "to": "0x097d4Aed5924e2172451973153Fc0e03407eD1F9",
      "funcSignature": "transfer(address,uint256)",
      "funcParams": ["0xRecipient...", "1000000"]
    }],
    "settings": { ... }
  }'

Using SmartWallet SDK

import { SmartWallet, PKSigner } from '@omnes/smartwallet-ts-sdk';

const smartWallet = await SmartWallet.create(...);

// Estimate gas
const { gasLimit, gasPrice } = await smartWallet.estimateGas(
  target,
  value,
  funcSignature,
  funcArgs,
  gasPrice || null,
  accessList
);

console.log('Gas limit:', gasLimit);
console.log('Gas price:', gasPrice);
console.log('Total:', gasLimit * gasPrice);

Gas Configuration

Configure gas overshoot for reliability using the SmartWallet SDK:

// Using SmartWallet SDK
import { PKSigner, SmartWallet } from '@omnes/smartwallet-ts-sdk';

const signer = await PKSigner.create(privateKey as `0x${string}`);
const smartWallet = await SmartWallet.create(
    signer.signMessage,
    signer.signMessage,
    signer.getEVMAddress(),
    rpcURL,
    apiKey
);

// Gas configuration is handled through the settings object in AccountOperations
const accountOperations: AccountOperations[] = [{
    account: {
        walletCustody: 1,
        salt: "user@example.com",
        publicKeys: []
    },
    operations: [operations],
    settings: {
        // Gas overshoot can be configured here if needed
        // The SDK provides defaults
    }
}];

Optimization Tips

Batch Operations: Group operations to save gas
Optimize Call Data: Minimize function parameters
Use Paymaster: Sponsor gas with ERC-20 tokens
Monitor Gas Prices: Execute during low gas periods
Estimate First: Always estimate before execution

Next Steps

Basic Execution - Execute transactions
Advanced Features - Troubleshoot gas issues

💡 Save Gas: Batch operations and use gas estimation to optimize transaction costs.