eXpress402 - Sentifi Trading Agent

AI cross-chain trading with real-time market sentiment

eXpress402 is a paid MCP server infrastructure for AI agents, implementing x402 v2 with wallet authentication. It provides two payment rails for accessing premium tools and data.

Payment Rails

Yellow Network Support

Off-chain session-based payments with instant settlement:

• Pay once, call many times - Create a session, make unlimited paid calls without per-transaction fees
• SIWx authentication - Wallet-based identity using CAIP-122 message signing
• Sub-millisecond lookups - Session mapping stored in Redis for instant authentication
• Zero gas fees - All payments settled off-chain on Yellow Network

Arc + Circle Gateway Support

On-chain payments with blockchain proof:

• USDC payments - Pay with Circle USDC on Arc Testnet
• On-chain verification - Every payment recorded on-chain for full transparency
• Circle Gateway integration - Seamless USDC handling through Circle's infrastructure
• Blockchain receipts - Verifiable payment proofs on Arc Testnet

Sentifi: Demo Trading Agent

Sentifi demonstrates eXpress402 in action - an autonomous AI trading agent that combines real-time market sentiment analysis with cross-chain DeFi execution. It uses eXpress402 MCP tools for paid market intelligence and LI.FI SDK for optimal swap routing across chains.

Wallet Setup

Generate an AI agent wallet for authentication and payments:

npm run generate-wallet

This creates:

• YELLOW_AGENT_PRIVATE_KEY - Your AI agent's wallet private key
• YELLOW_AGENT_ADDRESS - Your AI agent's public address

The wallet will be automatically funded with test tokens via Yellow Network faucet.

Environment Setup

Required environment variables (auto-configured by setup):

# Agent Wallet (auto-generated)
YELLOW_AGENT_PRIVATE_KEY=0x...
YELLOW_AGENT_ADDRESS=0x...

# Merchant Wallet (auto-generated)
YELLOW_MERCHANT_ADDRESS=0x...
YELLOW_MERCHANT_PRIVATE_KEY=0x...

# Optional: Market Research
TAVILY_API_KEY=your_tavily_key

# Optional: Redis (default works in devcontainer)
KV_URL=redis://redis:6379

Copy .env.example to .env and run:

npm run setup  # Generates wallets, funds them, installs dependencies

Run Sentifi

Start the trading agent with live dashboard:

npm run demo:sentifi

# Open dashboard in browser
open http://localhost:3456

The dashboard provides:

• Payment rail selector - Switch between Yellow Network (off-chain) and Arc Gateway (on-chain)
• Real-time sentiment analysis - Live market data from Reddit and news sources
• Trading decisions - AI-powered strategy with confidence scores
• Portfolio tracking - Real-time P&L and position monitoring

How Sentifi Uses eXpress402

Autonomous Decision Loop:

1. MONITOR - Fetch sentiment data via eXpress402 MCP tools (choose Yellow or Arc rail)
2. DECIDE - Analyze signals and determine strategy (bullish/bearish/neutral)
3. EXECUTE - Route trades through LI.FI SDK across 30+ DEXs for best prices
4. RECORD - Track P&L and update portfolio state

The dashboard lets you switch between payment rails to see both Yellow Network (off-chain) and Arc Gateway (on-chain) in action.

Configuration

Customize trading behavior via environment variables:

# Strategy Thresholds
SENTIFI_BULLISH_THRESHOLD=40      # Score above this = buy signal
SENTIFI_BEARISH_THRESHOLD=-40     # Score below this = sell signal
SENTIFI_MIN_CONFIDENCE=0.5        # Minimum confidence to trade

# Risk Management
SENTIFI_MAX_POSITION_PCT=25       # Max position size (% of portfolio)
SENTIFI_CONFIDENCE_SCALING=true   # Scale size by confidence

# Execution
SENTIFI_CHAIN_ID=42161            # Chain ID (Arbitrum One)

Additional Projects

Suifi: Alternative implementation using Sui blockchain for AI vault investment decisions. Records and evaluates DeFi vault strategies using DefiLlama data. Fully implemented in src/suifi/ but not integrated into the main demo due to time constraints.

For complete documentation, architecture details, and additional demos, see docs/README.md.