@bsv/sdk/docs/concepts/wallet-integration.md

BSV Blockchain Software Development Kit

# Wallet Integration

How the BSV TypeScript SDK connects with Bitcoin wallets and manages user authentication.

## Wallet Connection Model

The SDK uses a standardized approach to connect with Bitcoin wallets:

```typescript
import { WalletClient } from '@bsv/sdk'

// Connect to a wallet
const wallet = new WalletClient('https://wallet-url')

// Authenticate with the wallet
await wallet.authenticate()
```

## BRC-100 Compliance

The SDK follows the BRC-100 standard for wallet communication:

- **Standardized APIs**: Consistent interface across different wallets
- **Authentication**: Secure identity verification
- **Transaction Signing**: Wallet handles private key operations
- **UTXO Management**: Wallet manages available funds

## Authentication Flow

1. **Connection**: Establish connection to wallet service
2. **Identity**: Wallet provides user identity information
3. **Capabilities**: Discover what the wallet can do
4. **Authorization**: User grants permission for specific operations

## Transaction Creation

The wallet handles sensitive operations:

```typescript
// Create a transaction action
const action = await wallet.createAction({
  description: 'Payment transaction',
  outputs: [{
    satoshis: 1000,
    lockingScript: recipientScript
  }]
})

// Wallet signs and broadcasts automatically
```

## Key Benefits

### Security

- Private keys never leave the wallet
- User controls transaction approval
- Secure authentication protocols

### User Experience

- Familiar wallet interface
- Consistent across applications
- Single sign-on capabilities

### Developer Simplicity

- No key management complexity
- Standardized APIs
- Automatic UTXO handling

## Wallet Types

The SDK works with various wallet implementations:

- **Desktop Wallets**: Local applications with full control
- **Web Wallets**: Browser-based wallet services
- **Mobile Wallets**: Smartphone applications
- **Hardware Wallets**: Secure hardware devices

## Error Handling

Common wallet integration scenarios:

- Wallet not available or offline
- User denies transaction approval
- Insufficient funds in wallet
- Network connectivity issues

## Best Practices

- Always handle wallet connection failures gracefully
- Provide clear transaction descriptions to users
- Implement retry logic for network issues
- Cache wallet capabilities to improve performance

## Next Steps

- Learn about [Chain Tracking](./chain-tracking.md) for network data
- Understand [Key Management](./key-management.md) concepts
- Explore [Trust Model](./trust-model.md) considerations