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Overview

In this guide, you’ll learn how to enable Smart Wallet Sub Accounts in a Privy project. This allows your users to automatically create a Sub Account with Spend Permissions when connecting their wallet via Privy.

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Skip ahead

If you want to skip the setup and see a working demo, check out the Sub Accounts Privy Demo:

Sub Accounts Privy Demohttps://github.com/base/demos/tree/master/smart-wallet/sub-accounts-privy

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What you’ll achieve

By the end of this guide, you will:

  • Enable automatic Smart Wallet Sub Account creation for users authenticating with Privy
  • Set up Spend Permissions for Sub Accounts on Base Sepolia
  • Understand the required package versions and configuration

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Requirements

  • A Privy project
  • Smart Wallet Sub Accounts are only available on the canary version of the Coinbase Wallet SDK and on Base Sepolia
  • For now, you must also use a specific beta version of @privy-io/react-auth (see below)

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1. Override Required Package Versions

Sub Accounts require the latest canary version of @coinbase/wallet-sdk and a specific beta version of Privy React Auth. You must override these versions before installing packages.

Terminal
# If you have an existing node_modules or lock file, delete them first
rm -rf node_modules package-lock.json yarn.lock pnpm-lock.yaml

# Set the required overrides and dependencies in your package.json
npm pkg set overrides.@coinbase/wallet-sdk=canary
npm pkg set dependencies.@privy-io/react-auth=2.13.1-beta-20250512172154

# Now install dependencies
npm install

Important:

If you already have a lock file or node_modules, you must delete them before setting the overrides and reinstalling. Otherwise, the correct versions will not be installed and Sub Accounts will not work.

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2. Update Your Privy Provider Configuration

To enable Sub Accounts, update your Privy Provider configuration (usually in providers.tsx or similar):

providers.tsx
import { PrivyProvider } from "@privy-io/react-auth";
import { toHex, parseEther } from "viem";

<PrivyProvider
  appId={process.env.NEXT_PUBLIC_PRIVY_APP_ID || ""}
  config={{
    embeddedWallets: {
      createOnLogin: "all-users",
    },
    externalWallets: {
      coinbaseWallet: {
        config: {
          appName: "Privy Sub Accounts",
          appLogoUrl: "https://example.com/logo.png", // Replace with your logo
          preference: {
            keysUrl: "https://keys-dev.coinbase.com/connect", // Use the Smart Wallet dev environment
            options: "smartWalletOnly", // Only allow Smart Wallet
          },
          // Enable Sub Account support with Spend Permissions
          subAccounts: {
            enableAutoSubAccounts: true, // Automatically create a sub account on connect
            defaultSpendLimits: {
              84532: [ // Base Sepolia Chain ID
                {
                  token: "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE", // Native ETH
                  allowance: toHex(parseEther("0.01")), // 0.01 ETH
                  period: 86400, // 24 hours
                },
              ],
            },
          },
        },
      },
    },
  }}
>
  {/* ... your app ... */}
</PrivyProvider>

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Explanation of Key Parameters

  • keysUrl: Points to the Smart Wallet development environment. Sub Accounts only work in this environment.
  • options: 'smartWalletOnly': Ensures only Smart Wallet mode is used.
  • enableAutoSubAccounts: true: Automatically creates a Sub Account when the user connects.
  • defaultSpendLimits: Sets Spend Permissions from the global Smart Wallet to the Sub Account on Base Sepolia (84532).
    • token: The token address (native ETH in this example).
    • allowance: The max amount (in hex WEI) the Sub Account can spend in the period.
    • period: The time window for the allowance (in seconds, e.g., 86400 for 24h).

Note:

This guide only covers the automatic Sub Account creation flow, where a Sub Account is created and Spend Permissions are set as soon as the user connects their wallet. We are working with Privy to support flows where the user can first authenticate with their global Smart Wallet account and then create a Sub Account after. For now, only the automatic Sub Accounts flow is supported.

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3. Test Your Setup

  1. Start your development server:
Terminal
npm run dev
  1. Open your app and connect with Coinbase Wallet via Privy.
  2. You should see a prompt to create a Sub Account and Spend Permissions.
  3. You can now use the Sub Account to send transactions without pop-up confirmations.

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Additional Resources