> ## Documentation Index
> Fetch the complete documentation index at: https://docs.inco.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Privy

> Set up Privy wallet integration with Inco

## Scaffold

<CodeGroup>
  ```bash npm theme={null}
  npx create-inco-app@latest my-app --wallet privy --framework hardhat --chain evm --yes
  ```

  ```bash pnpm theme={null}
  pnpm create inco-app@latest my-app --wallet privy --framework hardhat --chain evm --yes
  ```

  ```bash yarn theme={null}
  yarn create inco-app my-app --wallet privy --framework hardhat --chain evm --yes
  ```

  ```bash bun theme={null}
  bunx create-inco-app@latest my-app --wallet privy --framework hardhat --chain evm --yes
  ```
</CodeGroup>

## Environment Setup

Get your Privy app ID from [dashboard.privy.io](https://dashboard.privy.io) and add it to `frontend/.env.local`:

```bash theme={null}
NEXT_PUBLIC_PRIVY_APP_ID=your_app_id_here
NEXT_PUBLIC_CONFLOTTERY_ADDRESS=<deployed_contract_address>
```

## Provider Setup

Privy wraps your app with `PrivyProvider` for authentication and uses its own `WagmiProvider` from `@privy-io/wagmi` (not the standard wagmi package) to bridge wallet state.

```tsx Providers.tsx theme={null}
"use client";

import { ReactNode } from "react";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import { PrivyProvider } from "@privy-io/react-auth";
import { WagmiProvider, createConfig } from "@privy-io/wagmi";
import { http } from "wagmi";
import { ThemeProvider } from "next-themes";
import { baseSepolia } from "wagmi/chains";

const queryClient = new QueryClient();

const appId = process.env.NEXT_PUBLIC_PRIVY_APP_ID || "";

const config = createConfig({
  chains: [baseSepolia],
  transports: {
    [baseSepolia.id]: http(),
  },
  ssr: true,
});

const Providers = ({ children }: { children: ReactNode }) => {
  return (
    <ThemeProvider attribute="class" defaultTheme="dark" enableSystem>
      <PrivyProvider
        appId={appId}
        config={{
          appearance: {
            theme: "dark",
          },
          embeddedWallets: {
            createOnLogin: "users-without-wallets",
          },
          defaultChain: baseSepolia,
          supportedChains: [baseSepolia],
        }}
      >
        <QueryClientProvider client={queryClient}>
          <WagmiProvider config={config}>{children}</WagmiProvider>
        </QueryClientProvider>
      </PrivyProvider>
    </ThemeProvider>
  );
};

export { Providers };
```

**Provider hierarchy:** `ThemeProvider` → `PrivyProvider` → `QueryClientProvider` → `WagmiProvider`

<Warning>
  The `WagmiProvider` import comes from `@privy-io/wagmi`, not the standard `wagmi` package. This is required for Privy's embedded wallet to work correctly with wagmi hooks.
</Warning>

Key config options:

* `embeddedWallets.createOnLogin: "users-without-wallets"` — automatically creates an embedded wallet for users who sign in via email/social but don't have an external wallet.
* `defaultChain` / `supportedChains` — locks the app to Base Sepolia.

## Inco SDK Integration

The Inco SDK works with the `walletClient` provided by wagmi (which Privy bridges through `@privy-io/wagmi`). Here's the core pattern:

```tsx useConfLottery.ts theme={null}
import { Lightning } from "@inco/js/lite";
import { handleTypes } from "@inco/js";
import { useAccount, useWalletClient, useWriteContract } from "wagmi";
import { parseEther } from "viem";

// Initialize Inco once
const zap = await Lightning.latest("testnet", 84532);

// Encrypt a value before sending on-chain
const { address } = useAccount();
const { data: walletClient } = useWalletClient();

async function deposit(amount: string) {
  const ciphertext = await zap.encrypt(parseEther(amount), {
    accountAddress: address,
    dappAddress: LOTTERY_ADDRESS,
    handleType: handleTypes.euint256,
  });

  const fee = await publicClient.readContract({
    address: zap.executorAddress,
    abi: getFeeAbi,
    functionName: "getFee",
  });

  writeContract({
    address: LOTTERY_ADDRESS,
    abi: confLotteryAbi,
    functionName: "deposit",
    args: [ciphertext],
    value: fee,
  });
}

// Decrypt with attestation
async function checkWinner() {
  const encryptedHandle = await publicClient.readContract({
    address: LOTTERY_ADDRESS,
    abi: confLotteryAbi,
    functionName: "getMyWinnerCheck",
    args: [currentRound],
    account: address,
  });

  const result = await zap.attestedDecrypt(walletClient, [encryptedHandle]);
  const isWinner = result[0].plaintext.value; // true or false
}
```

Whether the user connects with an external wallet or Privy's embedded wallet, wagmi's `useWalletClient()` provides the signer that Inco's `attestedDecrypt` uses for signing attestation requests.

## Dependencies

| Package                | Purpose                                   |
| ---------------------- | ----------------------------------------- |
| `@privy-io/react-auth` | Privy authentication & wallet management  |
| `@privy-io/wagmi`      | Privy-wagmi bridge (custom WagmiProvider) |
| `@inco/js`             | Inco encryption/decryption                |
| `wagmi`                | EVM wallet hooks                          |
| `viem`                 | Ethereum utilities                        |