Build payment-enabled agents in 5 minutes

Complete TypeScript monorepo with working agent examples that can autonomously pay for API access using payment protocols like x402, AP2, and more.

Get a working payment-enabled agent in under 5 minutes:

# 1. Clone and install
git clone https://github.com/xpaysh/agent-kit.git
cd agent-kit
pnpm install

# 2. Set up environment
cp .env.example .env
# Edit .env with your keys (see setup section below)

# 3. Start the mock API
npm run docker:up

# 4. Run an example agent
npm run start:demo

Your agent will start making autonomous payments for premium API access! 🎉

This monorepo provides everything you need to build x402-paying agents:

• @xpaysh/agent-kit-core - Core payment protocol client with spending controls
• @xpaysh/agent-kit-langchain - LangChain tools for autonomous payments
• @xpaysh/agent-kit-testing - Mock payment-protected API server for testing
• @xpaysh/agent-kit-examples - Working agent implementations

• apps/demo - Next.js web interface for testing agents

• Autonomous Payments - Agents pay for API access automatically
• Spending Controls - Daily limits, per-call limits, total budgets
• Multi-API Support - Weather, crypto, news, data analysis APIs
• Cost Transparency - Real-time cost tracking and reporting

• Spending Limits - Prevent runaway costs
• Payment Verification - Cryptographic proof of payments
• Error Recovery - Automatic retry with backoff
• Audit Trail - Complete payment history

• TypeScript First - Full type safety
• Easy Setup - Docker compose for instant development
• Live Examples - Working agents you can run immediately
• Comprehensive Docs - Integration guides for popular frameworks

• Node.js 18+ and pnpm 8+
• Docker and Docker Compose
• Ethereum wallet with testnet funds (Base Sepolia for x402, testnet for AP2)
• OpenAI API key

Create .env file:

# Required
OPENAI_API_KEY=your_openai_api_key
PRIVATE_KEY=your_ethereum_private_key

# Optional (uses defaults)
FACILITATOR_URL=http://localhost:3000
CHAIN_ID=84532
PAY_TO_ADDRESS=0x742d35Cc6631C0532925a3b8D000cE3D

1. Get Base Sepolia ETH: Base Sepolia Faucet
2. Get USDC: Use Circle's testnet faucet or swap ETH for USDC

⚠️ Security: Never use mainnet keys in development. Use testnet only.

Interactive agent that pays for multiple services:

npm run multi-api-agent

# Try asking:
# "What's the weather in Tokyo and current Bitcoin price?"
# "Get me tech news and analyze the sentiment"
# "Compare Ethereum and Bitcoin price trends"

APIs Used:

• Weather API: $0.01 per request
• Crypto Prices: $0.005 per request
• News API: $0.02 per request
• Data Analysis: $0.05 per request

Automated research workflows:

npm run research-agent

Demonstrates:

• Market research combining multiple APIs
• Travel planning with weather data
• Investment research with news + prices

Advanced data analysis:

npm run data-agent

Shows:

• Statistical analysis of datasets
• Correlation analysis between variables
• Trend analysis with forecasting

# Start all services
npm run docker:up

# Development mode
npm run dev

This starts:

• Mock x402 API server (port 3001)
• Local facilitator (port 3000)
• Demo web app (port 3002)

Visit http://localhost:3001/api for complete API documentation.

# Build all packages
npm run build

# Run tests
npm run test

# Type check
npm run typecheck

# Lint
npm run lint

agent-kit/
├── packages/
│   ├── core/           # Payment client & utilities
│   ├── langchain/      # LangChain integration
│   ├── mock-api/       # Test API server
│   └── examples/       # Agent implementations
├── apps/
│   └── demo/           # Web interface
└── docker-compose.yml  # Local development

sequenceDiagram
    participant Agent
    participant API
    participant Blockchain
    
    Agent->>API: Request data
    API->>Agent: 402 Payment Required
    Agent->>Blockchain: Pay USDC
    Agent->>API: Retry with payment proof
    API->>Agent: Return data

import { X402Agent, WeatherTool, CryptoPriceTool } from '@xpaysh/agent-kit-langchain';

const agent = new X402Agent({
  openaiApiKey: process.env.OPENAI_API_KEY!,
  privateKey: process.env.PRIVATE_KEY!,
  spendingLimits: {
    dailyLimit: 1.0,    // $1/day
    perCallLimit: 0.1   // $0.10/call
  },
  enabledTools: ['weather', 'crypto']
});

const result = await agent.invoke(
  "What's the weather in NYC and current Bitcoin price?"
);

import { X402Tool } from '@xpaysh/agent-kit-langchain';

const customTool = new X402Tool({
  toolName: 'premium_data',
  toolDescription: 'Access premium dataset ($0.10/request)',
  apiUrl: 'https://api.example.com/premium',
  privateKey: process.env.PRIVATE_KEY!,
  spendingLimits: { perCallLimit: 0.10 }
});

For production deployments, use {xpay✦} Smart Proxy to route all your agent's API calls through a managed infrastructure with enterprise-grade spending controls and observability:

import { X402Agent } from '@xpaysh/agent-kit-langchain';

const agent = new X402Agent({
  openaiApiKey: process.env.OPENAI_API_KEY!,
  // Point all API calls through Smart Proxy
  proxyConfig: {
    proxyUrl: 'https://proxy.xpay.sh/your-customer-id/your-agent-id',
    apiKey: process.env.XPAY_API_KEY!
  },
  spendingLimits: {
    dailyLimit: 50.0,    // $50/day managed by Smart Proxy
    perCallLimit: 5.0    // $5/call safety limit
  }
});

// All API calls are automatically:
// ✅ Routed through Smart Proxy
// ✅ Payment-enabled (x402/AP2)  
// ✅ Spending-controlled
// ✅ Logged and monitored
// ✅ Cached for performance

const result = await agent.invoke(
  "Get weather for London, crypto prices for BTC/ETH, and latest tech news"
);

Benefits:

• Zero Payment Friction: Smart Proxy handles all payment protocols automatically
• Enterprise Spending Controls: Daily limits, per-call limits, budget management
• Real-time Observability: Transaction logs, spending analytics, cost optimization
• Multi-Protocol Support: x402, AP2, and future protocols without code changes
• Performance: Intelligent caching and request optimization

Smart Proxy Features:

• 🛡️ Spending Controls: Prevent runaway costs with configurable limits
• 💳 Payment Automation: Auto-pay for x402/AP2 APIs transparently
• 📊 Real-time Analytics: Track spending, usage patterns, and cost optimization
• ⚡ Performance: Sub-500ms latency with global edge deployment
• 🔒 Security: Non-custodial, enterprise-grade security

Learn more about Smart Proxy →

Part of the {xpay✦} opensource ecosystem:

• awesome-x402 - Curated payment protocol resources
• x402-local - Local development environment
• x402-sdk - TypeScript-first payment protocol SDK
• x402-server-kit - Server middleware

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

git clone https://github.com/xpaysh/agent-kit.git
cd agent-kit
pnpm install
npm run dev

MIT License - see LICENSE for details.

• Documentation: Full docs
• Examples: Live examples
• Issues: GitHub Issues
• Discord: {xpay✦} Community

🚀 Built by {xpay✦} - Enabling autonomous agents to pay for services across all payment protocols

awesome-x402 • x402-local • agent-kit • x402-sdk