Privy

Privy logs users in with email, SMS, Google/Twitter/Discord, passkeys or an external wallet, and gives each user an embedded EVM (or Solana) wallet with no seed phrase. Pick it when your users are not crypto-native and you want "log in with email, get a wallet" in a React or Next.js app. Skip it for a pure backend bot, or when every user already has MetaMask and you only need a connect button (plain wagmi or RainbowKit is lighter).

Quickstart

1. Create an app at https://dashboard.privy.io. Copy the App ID (and App secret for your server) from Configuration > App settings > Basics. Enable Email (and Google) under the Authentication / login methods page.
2. Install (Next.js App Router):

   npm i @privy-io/react-auth@3.50.0 viem@2.57.5

3. .env.local: NEXT_PUBLIC_PRIVY_APP_ID=<YOUR_PRIVY_APP_ID> (the real ID is 25 characters; a fake or empty value crashes next build).
4. app/providers.tsx, and wrap {children} with <Providers> in app/layout.tsx:

   'use client';
   import {PrivyProvider} from '@privy-io/react-auth';
   import {worldchainSepolia, unichainSepolia} from 'viem/chains';
   
   export default function Providers({children}: {children: React.ReactNode}) {
     return (
       <PrivyProvider
         appId={process.env.NEXT_PUBLIC_PRIVY_APP_ID!}
         config={{
           loginMethods: ['email', 'google', 'wallet'],
           embeddedWallets: {ethereum: {createOnLogin: 'users-without-wallets'}},
           defaultChain: worldchainSepolia,
           supportedChains: [worldchainSepolia, unichainSepolia]
         }}
       >
         {children}
       </PrivyProvider>
     );
   }

5. app/page.tsx: log in with the Privy modal, read the embedded wallet, send a transaction:

   'use client';
   import {usePrivy, useWallets, useSendTransaction} from '@privy-io/react-auth';
   
   export default function Home() {
     const {ready, authenticated, user, login, logout} = usePrivy();
     const {wallets} = useWallets();
     const {sendTransaction} = useSendTransaction();
     if (!ready) return <p>Loading...</p>;
     if (!authenticated) return <button onClick={login}>Log in</button>;
     const embedded = wallets.find((w) => w.walletClientType === 'privy');
     return (
       <div>
         <p>{user?.id} / {embedded?.address ?? 'creating wallet...'}</p>
         <button disabled={!embedded} onClick={async () => {
           const {hash} = await sendTransaction(
             {to: '0x0000000000000000000000000000000000000000', value: 1n, chainId: 4801},
             {address: embedded!.address});
           alert(hash);
         }}>Send 1 wei</button>
         <button onClick={logout}>Log out</button>
       </div>
     );
   }

6. npm run dev, open http://localhost:3000, log in with your email. Fund the wallet with World Chain Sepolia test ETH before sending.

Full walkthrough: references/quickstart.md.

Common tasks

• Custom email OTP login form (whitelabel) + creating the wallet yourself
• Google / social login button
• Send ETH or an ERC-20 from the embedded wallet
• Use viem with a Privy wallet
• Use wagmi hooks with Privy
• Verify the user on your server (access token)
• Add World Chain / Unichain or any custom chain
• World mini app login with the World wallet (SIWE)
• Errors and gotchas: references/errors.md
• Chain support: references/chains.md · Docs MCP server: references/mcp.md

Before you write more code

• For anything not covered here, read the index https://docs.privy.io/llms.txt and open the linked .md page (React: https://docs.privy.io/basics/react/setup.md). Privy also runs a docs MCP server (references/mcp.md).
• Check versions first: npm view @privy-io/react-auth version. Privy ships often (3.48 to 3.50 in one week, Oct 2026).
• Use @privy-io/node on the server. @privy-io/server-auth is deprecated on npm.
• Some doc snippets are behind the SDK types (see errors.md #1 and #2). Type-check with tsc. When this skill and the official docs disagree, the docs win, unless the installed package's TypeScript types say otherwise.

At ETHGlobal Mumbai

• Sponsor chains: World Chain and Unichain work as normal EVM chains, mainnet and Sepolia testnets, both in viem/chains. Details and sources: references/chains.md.
• Privy may help with the World and Uniswap Foundation (Unichain) tracks (consumer onboarding, mini apps, payments) and with any track that needs non-crypto users to sign in. Check the rules yourself: https://ethglobal.com/events/mumbai/prizes
• Help: Privy support Slack https://privy.io/slack (linked from the docs), docs https://docs.privy.io

About

Hand-written for Backboard (https://backboard.0xvikram.me), an independent project not affiliated with ETHGlobal or Privy. Tested 2026-10-19 with @privy-io/react-auth@3.50.0, @privy-io/node@0.36.0, @privy-io/wagmi@4.0.19, wagmi@3.7.7, viem@2.57.5, next@16.4.2.