Kosh Wallet

A non-custodial, keyless mobile wallet with AI-powered DeFi capabilities across 8 blockchain networks.

Key Features

Keyless Architecture

• Deterministic wallet generation from Google OAuth credentials (no seed phrases to manage)
• SHA-256 hashing with stable identifiers (email + userId)
• Same wallet address recovered across all devices automatically

Passkey & Biometric Security

• Face ID / Touch ID authentication for transaction signing
• 6-digit PIN fallback when biometrics unavailable
• AES-256-CBC encryption with PBKDF2 key derivation (100,000 iterations)
• Rate limiting: 5 failed attempts triggers 5-minute lockout

Client-Only Non-Custodial Design

• Private keys are never stored in React state or sent to servers
• On-demand key generation from encrypted storage
• Auto-wipe from memory after 30 seconds of inactivity
• Keys only decrypted during transaction signing with biometric gate

Multi-Chain Support

Network	Chain ID	Native Token
Ethereum	1	ETH
BNB Chain	56	BNB
Polygon	137	MATIC
Arbitrum	42161	ETH
Avalanche	43114	AVAX
Base	8453	ETH
Optimism	10	ETH
Stellar	-	XLM (Ed25519)

• Automatic RPC fallback and health checking
• EIP-1559 transaction support where available

AI DeFi Assistant

• Natural language commands: "Swap 100 USDC to ETH on Polygon"
• Groq (Llama 3.3 70B) for fast inference with Gemini fallback
• Supported actions: Swap, Bridge, Send, Buy
• Intelligent parameter collection with conversation context

DeFi Integrations

• 0x Protocol for DEX aggregation and best-price routing
• Symbiosis for cross-chain bridges
• Transak for fiat on/off-ramp
• Moralis for multi-chain balance fetching

Investment Features

• SIP (Systematic Investment Plans)
• Pre-built bundles: Blue-chip, DeFi Index, AI Frontier
• Portfolio tracking with real-time analytics

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                        User Device                               │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│   ┌──────────────┐    ┌──────────────┐    ┌──────────────┐     │
│   │   Google     │───▸│ Deterministic│───▸│   Biometric  │     │
│   │   OAuth      │    │ Key Gen      │    │   Gate       │     │
│   └──────────────┘    │ (SHA-256)    │    │ (Face/Touch) │     │
│                       └──────────────┘    └──────┬───────┘     │
│                                                  │              │
│                                                  ▼              │
│   ┌──────────────┐    ┌──────────────┐    ┌──────────────┐     │
│   │   AES-256    │◀───│   Key        │◀───│  Transaction │     │
│   │   Encrypted  │    │   Decrypt    │    │   Sign       │     │
│   │   Storage    │    │   (PBKDF2)   │    └──────┬───────┘     │
│   └──────────────┘    └──────────────┘           │              │
│                                                  │              │
│                                           ┌──────▼───────┐      │
│                                           │  Auto-Clear  │      │
│                                           │  (30 sec)    │      │
│                                           └──────────────┘      │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

Tech Stack

Category	Technologies
Mobile	React Native 0.81, Expo 54, React 19
Language	TypeScript 5.9
Web3	Viem, Web3.js, @stellar/stellar-sdk
State	Redux Toolkit, Context API, Redux Persist
Security	expo-secure-store, expo-local-authentication, crypto-js
AI	Groq API (Llama 3.3 70B), Google Generative AI
Trading	0x Protocol, Symbiosis, Moralis, Transak

Quick Start

Prerequisites

• Node.js 18+
• Expo CLI
• iOS Simulator or Android Emulator (or physical device)

Installation

# Clone the repository
git clone https://github.com/rohansingh4/Kosh.git
cd Kosh

# Install dependencies
yarn install

# Start development server
yarn start

Running on Device

# iOS
yarn ios

# Android
yarn android

# With dev client
npx expo start --dev-client

Environment Variables

Create a .env file in the root directory:

EXPO_PUBLIC_GROQ_API_KEY=your_groq_key
EXPO_PUBLIC_GEMINI_API_KEY=your_gemini_key
EXPO_PUBLIC_ZEROX_API_KEY=your_0x_key
EXPO_PUBLIC_MORALIS_API_KEY=your_moralis_key
EXPO_PUBLIC_TRANSAK_API_KEY=your_transak_key
EXPO_PUBLIC_ENCRYPTION_SALT=your_custom_salt

Security Model

Kosh implements a client-only non-custodial architecture:

1. No Seed Phrases: Wallet is deterministically generated from Google OAuth credentials using SHA-256 hashing of stable identifiers (email + userId + Firebase config).

2. Zero Server Storage: Private keys never leave the device. No backend stores or transmits key material.

3. Encrypted at Rest: Keys stored using AES-256-CBC with:

   • Device-specific salt (unique per installation)
   • PBKDF2 key derivation (100,000 iterations)
   • Stored in iOS Keychain / Android Keystore via expo-secure-store

4. Biometric Gating: Every transaction requires Face ID/Touch ID authentication before the key is decrypted.

5. Memory Safety:

   • Keys are never stored in React state
   • Auto-wipe from memory after 30 seconds
   • Secure string overwrite before garbage collection

6. Rate Limiting: 5 failed authentication attempts trigger a 5-minute lockout to prevent brute force attacks.

Project Structure

KoshWallet/
├── components/          # Reusable UI components
│   ├── modals/         # Modal dialogs
│   ├── navigation/     # Navigation components
│   └── trade/          # Trading UI components
├── config/             # Configuration files
│   ├── tokenList.json  # Supported tokens
│   └── tradeConst.ts   # Network configurations
├── contexts/           # React contexts
├── screens/            # Screen components
├── services/           # API services
│   ├── geminiService.ts    # AI assistant
│   ├── ZeroXService.ts     # DEX aggregation
│   └── symbiosisService.ts # Cross-chain bridges
├── utils/              # Utility functions
│   ├── passkeyWallet.ts    # Keyless wallet generation
│   ├── keyManager.ts       # Secure key storage
│   ├── SecureKeyService.ts # Transaction signing
│   └── encryption.ts       # AES encryption
└── store/              # Redux store

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

MIT License - see LICENSE for details.

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Built with React Native & Expo