Midnight Dapp:wallet Integration

Wallet Integration

Connect Lace wallet to your Midnight DApp for user authentication, account management, and transaction signing.

When to Use

• Setting up wallet connection for the first time
• Handling multiple user accounts
• Switching between testnet and mainnet
• Troubleshooting wallet connection issues
• Migrating from MetaMask/Web3 patterns

Key Concepts

Browser Wallet Pattern

Lace wallet is a Chrome extension that injects window.midnight.mnLace into web pages. This is similar to MetaMask's window.ethereum but with Midnight-specific APIs.

Connection Flow

1. Check availability - Verify Lace extension is installed
2. Request authorization - User approves DApp access
3. Get wallet state - Retrieve address, public keys
4. Configure providers - Set up indexer and proof server connections

Address Format

Midnight uses Bech32m addresses (e.g., addr_test1qz...) instead of Ethereum's hex format (0x...).

References

Examples

Quick Start

1. Check Wallet Availability

const wallet = window.midnight?.mnLace;
if (!wallet) {
  // Show "Install Lace Wallet" prompt
  throw new Error('Lace wallet not installed');
}

2. Request Authorization

const walletAPI = await wallet.enable();
// User sees approval popup in Lace

3. Get Wallet State

const state = await walletAPI.state();
console.log('Address:', state.address);
console.log('Coin Public Key:', state.coinPublicKey);

4. Get Service URLs

const uris = await wallet.serviceUriConfig();
// { indexerUri, indexerWsUri, proverServerUri }

Common Patterns

Connection State Hook

function useMidnightWallet() {
  const [connected, setConnected] = useState(false);
  const [address, setAddress] = useState<string | null>(null);
  const [error, setError] = useState<Error | null>(null);

  const connect = async () => {
    try {
      const wallet = window.midnight?.mnLace;
      if (!wallet) throw new Error('Lace not installed');

      const api = await wallet.enable();
      const state = await api.state();

      setAddress(state.address);
      setConnected(true);
    } catch (e) {
      setError(e as Error);
    }
  };

  return { connected, address, error, connect };
}

Display Address

function formatAddress(address: string): string {
  // Bech32m addresses are long - truncate for display
  if (address.length <= 20) return address;
  return `${address.slice(0, 12)}...${address.slice(-8)}`;
}

Related Skills

• proof-handling - Transaction signing flow after wallet connection
• transaction-flows - Submitting transactions via wallet
• error-handling - Wallet error messages and recovery

Related Commands

• /dapp-check - Validates wallet provider configuration
• /dapp-debug wallet - Diagnose wallet connection issues