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Overview

Smart Accounts unlock the ability for developers to sponsor gas on their users’ transactions. With the CDP SDK, it’s simple to integrate any paymaster URL and cover gas costs for all transactions originating from your smart accounts. You can refer to this guide on how to set up a CDP Paymaster. You could also use any provider of your choice.

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Benefits:

  • Removes the friction of requiring users to hold ETH
  • Enables users to interact with your app immediately
  • Provides a more familiar Web2-like experience for new users
  • Allows you to subsidize or fully cover transaction costs for your users
  • Gives you control over which transactions you want to sponsor

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Prerequisites

  • A Coinbase Developer Platform account
  • The following environment variables in your .env file:
CDP_API_KEY_ID=your_api_key_id
CDP_API_KEY_SECRET=your_api_key_secret
CDP_WALLET_SECRET=your_wallet_secret
Navigate to the CDP Portal to find or create your wallet secret, walletid, and client api key
All user operations on Base Sepolia are sponsored by default. For mainnet, you can specify a paymaster of your choice as follows: 
import dotenv from "dotenv";
import { parseEther } from "viem";
import { CdpClient } from "@coinbase/cdp-sdk";

dotenv.config();

const cdp = new CdpClient({
  apiKeyId: process.env.CDP_API_KEY_ID,
  apiKeySecret: process.env.CDP_API_KEY_SECRET,
  walletSecret: process.env.CDP_WALLET_SECRET,
});

const account = await cdp.evm.createAccount();

const smartAccount = await cdp.evm.createSmartAccount({
  owner: account,
});

const userOperation = await cdp.evm.sendUserOperation({
  smartAccount: smartAccount,
  network: "base-sepolia",
  calls: [
    {
      to: "0x0000000000000000000000000000000000000000",
      value: parseEther("0"),
      data: "0x",
    },
  ],
  paymasterUrl: "https://some-paymaster-url.com",
});

console.log("User Operation Result:", userOperation);
You can apply for gas credits as you scale.

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Gas sponsorship with EIP-7702 delegated accounts

If you’re using EIP-7702 delegation to upgrade an existing EOA with smart account capabilities, gas sponsorship works the same way — pass a paymasterUrl to sendUserOperation on the delegated account.
The account must have completed EIP-7702 delegation before sending user operations. See the EIP-7702 Delegation guide for the full delegation flow.
import { CdpClient, toEvmDelegatedAccount } from "@coinbase/cdp-sdk";
import { parseEther } from "viem";
import dotenv from "dotenv";

dotenv.config();

const cdp = new CdpClient();

// Retrieve the account that has already been delegated
const account = await cdp.evm.getOrCreateAccount({ name: "My-EIP7702-Account" });

const delegatedAccount = toEvmDelegatedAccount(account);

const { userOpHash } = await delegatedAccount.sendUserOperation({
  network: "base-sepolia",
  calls: [
    {
      to: "0x0000000000000000000000000000000000000000",
      value: parseEther("0"),
      data: "0x",
    },
  ],
  paymasterUrl: "https://some-paymaster-url.com",
});

console.log("User operation submitted:", userOpHash);

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Common Issues

  • If transactions fail, verify your gas estimates
  • If paymaster fails, check your paymaster client and network configuration
  • Make sure your environment variables are properly set in your .env file
  • Verify you’re on the correct network before proceeding with transactions

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Additional Resources