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Gelato Smart Wallet Integration Guide

You can use Gelato Smart Wallet to enable gasless transactions on Flow EVM. It supports features like: EIP-7702 or ERC-4337 depending on the wallet you use.

Prerequisites of using Gelato Smart Wallet​

You need to setup all the followings in the Gelato App to create a Gelato Sponsor API Key.

Step 1. Create Your Gelato Account​

Sign up on the Gelato App to establish an account. This account is the foundation for setting up relay tasks and managing gas sponsorships.

Step 2. Create a Relay App​

Within your Gelato account, create a new Relay App with the Flow EVM network.
For Testnet, you can first allow Any contract to call your relay app.

Create a Relay App

note

You can add more smart contract information and its associated chain information later in this App.
When set to a specific contract instead of Any contract, the API keys will only allow gasless transactions for calls to the designated methods within the ABI of the contract.

Step 3. Create/Obtain a Sponsor API Key​

After creating the relay app, navigate to its dashboard to locate your Sponsor API Key.

Create a Sponsor API Key

This key links your Gelato setup with 1Balance for gas sponsorship.

Step 4. Deposit Funds into 1Balance​

To use Gelato sponsoring transactions, you need to deposit funds into 1Balance according to your target environment:

  • Mainnets: Deposit USDC.
  • Testnets: Deposit Sepolia ETH.

Here we use Sepolia ETH as the gas fee for Testnet‘s gasless transactions.

Deposit Funds into 1Balance

Here are some third party Sepolia ETH faucets you can use:

Send Gasless Transactions for your users​

After you have created a Sponsor API Key and deposited funds into 1Balance, you can use gasless transactions features for your users.
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.

note

You can find the examples in the Gelato Smart Wallet SDK repository.

Step 1. Install all relevant dependencies​


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pnpm add @gelatodigital/smartwallet viem

Step 2. Setup Smart Wallet Account​

Import required dependencies:


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import { createGelatoSmartWalletClient, sponsored } from "@gelatonetwork/smartwallet";
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import { gelato } from "@gelatonetwork/smartwallet/accounts";
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import { createWalletClient, createPublicClient, http, type Hex } from "viem";
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import { generatePrivateKey, privateKeyToAccount } from "viem/accounts";
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import { flowTestnet } from "viem/chains";
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// Create a public client for the Flow Testnet
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const publicClient = createPublicClient({
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chain: flowTestnet,
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transport: http(),
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});

You can set up a Smart Account as per your needs.
Once you create the gelato account, the Gelato Smart Account address will be the same as your EOA, enabling EIP-7702 features.


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// Prepare a normal EOA account
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const privateKey = (process.env.PRIVATE_KEY ?? generatePrivateKey()) as Hex;
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const owner = privateKeyToAccount(privateKey);
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// Wrap the EOA account into a Gelato Smart account
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const account = await gelato({
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owner,
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client: publicClient,
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});

Then you need to create a standard viem wallet client with the Gelato Smart Account.


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

Once you have a standard viem wallet client, you can wrap it into a Gelato Smart Wallet client with the sponsor API key.


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const sponsorApiKey = process.env.SPONSOR_API_KEY;
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if (!sponsorApiKey) {
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throw new Error("SPONSOR_API_KEY is not set");
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}
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const swc = await createGelatoSmartWalletClient(client, {
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apiKey: sponsorApiKey
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});

Step 3. Estimate or Send a Gasless Transaction​

Now you can estimate or send a gasless transaction with the Gelato Smart Wallet client.

To estimate the fee and gas for a gasless transaction, you can use the estimate method.


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const response = await swc.estimate({
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payment: sponsored(sponsorApiKey),
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calls: [
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{
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to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
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data: "0xd09de08a",
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value: 0n
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}
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]
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});
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console.log(`Estimated fee: ${formatEther(BigInt(response.fee.amount))} FLOW`);
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console.log(`Estimated gas: ${JSON.stringify(response.gas)} GAS`);

To send a gasless transaction, you can use the execute method.


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const results = await smartWalletClient.execute({
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payment : sponsored(sponsorApiKey),
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calls: [
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{
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to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
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data: "0xd09de08a",
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value: 0n
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}
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]
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});
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console.log("userOp hash:", results?.id);
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const txHash = await results?.wait();
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console.log("transaction hash",txHash);

Or you can use prepare + send to send a gasless transaction.


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const preparedCalls = await swc.prepare({
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payment: sponsored(sponsorApiKey),
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calls: [
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{
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to: "0xa8851f5f279eD47a292f09CA2b6D40736a51788E",
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data: "0xd09de08a",
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value: 0n
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}
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]
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});
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// Other actions can be performed here
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const results = await swc.send({
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preparedCalls
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});
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// You can listen for events from the Gelato Smart Wallet client
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results.on("submitted", (status: GelatoTaskStatus) => {
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console.log(`Transaction submitted: ${status.transactionHash}`);
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});
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results.on("success", async (status: GelatoTaskStatus) => {
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console.log(`Transaction successful: ${status.transactionHash}`);
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});
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results.on("error", (error: Error) => {
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console.error(`Transaction failed: ${error.message}`);
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});

Conclusion​

So far, you’ve learned how to send sponsored EIP-7702 transactions using a Gelato Smart Wallet on Flow EVM.

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