Sponsor gas for your users

Sponsoring gas for users is one of the most effective ways to enhance the user experience in dApps. With the Gelato Smart Wallet SDK, developers can easily set up sponsored transactions for their applications in just a few simple steps, enabling seamless onboarding and interaction without requiring users to hold native tokens.

Steps

1. Import required dependencies

import { createGelatoSmartWalletClient, sponsored } from "@gelatonetwork/smartwallet";
import { createWalletClient, http } from "viem";
import { generatePrivateKey, privateKeyToAccount } from "viem/accounts";

2. Setup Wallet Client

Quickly get started by creating a wallet client using createWalletClient from viem with local account for your specified network. Checkout supported networks .

const privateKey = (process.env.PRIVATE_KEY ?? generatePrivateKey()) as Hex;
const account = privateKeyToAccount(privateKey);

const client = createWalletClient({
  account,
  chain: baseSepolia,
  transport: http()
});

3. Create Smart Wallet Client

To create a Sponsor API Key, visit the Gelato App and navigate to the Relay section. Create a new app, select the required networks, and copy the generated Sponsor API Key.

A Smart Wallet Client serves as an alternative to the standard viem walletClient, but is purpose-built for managing EOA's as smart wallets instead of traditional EOA (Externally Owned Accounts). To initialize a Smart Wallet Client, you can use the createGelatoSmartWalletClient method.

const smartWalletClient = createGelatoSmartWalletClient(client, {
    apiKey: sponsorApiKey 
});

A Kernel Wallet Client serves as an alternative to the standard viem walletClient, but is purpose-built for managing smart contract wallets instead of traditional EOA (Externally Owned Accounts).

const kernelWalletClient = createGelatoSmartWalletClient(client, {
  apiKey: sponsorApiKey,
  wallet: "kernel",
});

4. Sending transactions

To send sponsored transactions, select Sponsored as the payment method.

const results = await smartWalletClient.execute({
    payment : sponsored(),
    calls: [
      {
        to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
        data: "0xd09de08a",
        value: 0n
      }
    ]
});

console.log("userOp hash:", results?.id);
const txHash = await results?.wait();
console.log("transaction hash",txHash);

const results = await kernelWalletClient.execute({
    payment : sponsored(),
    calls: [
      {
        to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
        data: "0xd09de08a",
        value: 0n
      }
    ]
});

console.log("userOp hash:", results?.id);
const txHash = await results?.wait();
console.log("transaction hash",txHash);

5. Batch multiple transactions

You can batch multiple transactions to be sent on-chain at once by adding them to the calls array.

const results = await smartWalletClient.execute({
    payment : sponsored(SPONSOR_API_KEY),
    calls: [
      {
        to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
        data: "0xd09de08a",
        value: 0n
      },
      {
        to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
        data: "0xd09de08a",
        value: 0n
      },
      {
        to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
        data: "0xd09de08a",
        value: 0n
      },
    ]
});

So far, you’ve learned how to send sponsored EIP-7702 transactions using a smart EOA and kernel wallets. Next, explore different gas payment methods using smart wallets, including Kernel wallets (ERC-4337).

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Last updated 19 hours ago