david-dacruz/engrave-protocol

🪶 Engrave Protocol

Pay-per-use Bitcoin mempool data for AI Agents via x402 micropayments on Solana

Built for Solana x402 Hackathon (MCP Track)

🧩 Overview

Engrave Protocol is an MCP (Model Context Protocol) Server that gives AI Agents access to Bitcoin blockchain data through micropayment-protected APIs.

Instead of expensive monthly subscriptions, AI agents pay tiny amounts (as low as $0.01 USDC) for each query they make. Payments are instant via Solana, and the data comes from Bitcoin's mempool.

Key Innovation: No API keys, no subscriptions, no upfront costs. Payment IS authentication.

❗ Problem Statement

Traditional blockchain data APIs require:

• $99+/month subscriptions (regardless of usage)
• API key management (security risks)
• Rate limits (even if you pay)
• Wasted money if you don't use it

For AI Agents with unpredictable, on-demand usage patterns, this model is broken.

⚙️ Solution

True pay-as-you-go API access powered by:

• x402 HTTP Payment Protocol - Payment requirements via 402 status code
• Solana USDC micropayments - Instant, sub-cent transactions
• MCP Integration - Seamless AI agent access via Claude, Gemini, etc.
• Bitcoin Mempool Data - Real-time blockchain analytics

AI Agent asks: "What are current Bitcoin fees?"
     ↓
Pays $0.01 USDC on Solana (instant)
     ↓
Gets live mempool data
     ↓
AI responds with fee recommendations

🚀 Quick Start

Prerequisites

• Node.js 18+ installed
• MCP-compatible client (Claude Desktop recommended)
• Solana wallet with USDC on Devnet

1. Install & Setup

# Clone and install
git clone https://github.com/david-dacruz/engrave-protocol.git
cd engrave-protocol/api
npm install

# Configure environment
cp .env.example .env
# Edit .env with your treasury wallet address

2. Start API Server

cd api
npm run dev

# API starts on http://localhost:3000
# Test health: curl http://localhost:3000/health

3. Create MCP Wallet

# Generate wallet for MCP server (stores in api/mcp_wallet.json)
npm run mcp:create-wallet

# Fund wallet with USDC on Solana Devnet
# Visit: https://faucet.circle.com

4. Configure Your MCP Client

For Claude Code CLI:

cd engrave-protocol/api
claude mcp add engrave-protocol \
  -e PORT=3000 \
  -e TREASURY_WALLET_ADDRESS=your_solana_treasury_address \
  -- sh -c "cd $(pwd) && node src/mcp/server.js"

For Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json):

{
	"mcpServers": {
		"engrave-protocol": {
			"command": "sh",
			"args": [
				"-c",
				"cd /ABSOLUTE/PATH/TO/engrave-protocol/api && node src/mcp/server.js"
			],
			"env": {
				"PORT": "3000",
				"TREASURY_WALLET_ADDRESS": "your_solana_treasury_address"
			}
		}
	}
}

5. Test It!

Restart Claude Desktop and try:

What are the current Bitcoin testnet fee recommendations?

The MCP server will automatically:

• Pay $0.01 USDC on Solana
• Query the mempool API
• Return live fee data

🔧 Available MCP Tools (8 Total)

All prices in USDC on Solana Devnet

🏗️ Architecture

┌────────────────────────────────────────┐
│  AI Agent (Claude/Gemini)              │
│  "What are Bitcoin fees?"              │
└──────────────┬─────────────────────────┘
               │ MCP Protocol (stdio)
               ▼
┌────────────────────────────────────────┐
│  MCP Server (Engrave Protocol)         │
│  • Manages Solana wallet               │
│  • Handles x402 payments               │
│  • 8 mempool query tools               │
└──────────────┬─────────────────────────┘
               │ HTTP + x402-axios
               ▼
┌────────────────────────────────────────┐
│  Express API (Payment Gateway)         │
│  • Verifies payment signatures         │
│  • Rate limiting (10 req/s)            │
│  • Async payment settlement            │
└──────────────┬─────────────────────────┘
               │ Rate-limited HTTP
               ▼
┌────────────────────────────────────────┐
│  Mempool.space API                     │
│  • Bitcoin blockchain data             │
│  • Testnet & Mainnet support           │
└────────────────────────────────────────┘

Key Innovation: Payment happens transparently between MCP server and API, user just asks questions.

💡 Example Use Cases

1. Trading Bot

Monitor mempool congestion every 30 seconds to time transactions
Cost: $0.03/check = $87/day (if running 24/7)
Traditional API: $300/month (whether you use it or not)
Savings: 70-99% depending on actual usage

2. Blockchain Explorer

User queries their transaction → pay $0.10 → return data
Explorer charges user $0.12 (20% markup)
Zero fixed costs, instant profit margin

3. Research & Analysis

Academic studying Bitcoin patterns sporadically
Heavy analysis: $50/week when active
Quiet periods: $0/week
Traditional API: $99/month ALWAYS
Savings: ~$600/year

4. AI Assistant

User: "Should I send my Bitcoin transaction now?"
Agent: Checks fees ($0.01) + mempool stats ($0.01)
Agent: "Fees are low at 3 sat/vB, good time to send!"
Total cost: $0.02 per question

📊 Cost Comparison

Traditional API (mempool.space equivalent)

• Monthly subscription: $99/month
• Annual cost: $1,188/year
• Cost per query (30/month): $3.30
• Wasted if unused: $99/month

Engrave Protocol

• Pay per query: $0.01 - $0.25
• Annual cost: Only what you use
• Cost per query: $0.01 - $0.25
• Wasted if unused: $0.00

Break-even point: ~400 queries/month

🛠️ Development Scripts

# API Server
npm run dev              # Start API with hot reload
npm run start            # Start API in production mode

# MCP Server
npm run mcp:create-wallet # Generate new MCP wallet
npm run mcp:inspect # Test MCP server with inspector

# Testing
npm run dev
npm run test

🔐 Security Notes

• ⚠️ Development Only: Currently on Bitcoin testnet + Solana devnet
• 💰 Limited Funds: Keep minimal USDC in MCP wallet
• 🔒 Environment Variables: Use .env for sensitive config

🤝 Contributing

This project is built for the Solana x402 Hackathon (MCP Track).

Contributions welcome:

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

🔗 Links

• Landing page: https://engrave-protocol.ai/
• GitHub: https://github.com/david-dacruz/engrave-protocol
• Twitter: https://x.com/engraveprotocol
• x402 Protocol: https://solana.com/developers/guides/getstarted/intro-to-x402
• MCP Protocol: https://modelcontextprotocol.io
• USDC Faucet: https://faucet.circle.com
• Mempool.space: https://mempool.space

Built during the Solana x402 Hackathon 🏆 Making blockchain data affordable for AI Agents

📁 Resources

This repository includes several supporting materials for demos, developers, and presentations.

🎥 Demo

• Hackathon Demo Video
  Short demonstration video created for the Solana x402 Hackathon.

👨‍💻 Developer Docs

• API Endpoints (PDF)
  Detailed documentation of API endpoints for developers integrating Engrave Protocol.

🪄 Pitch Deck

• Pitch Deck (HTML)
• Pitch Deck (Markdown)
• Pitch Deck (PDF)
• Pitch Deck Notes

Each resource provides a different format or view of the Engrave Protocol presentation and developer materials.

🪶 Engrave Protocol - Pay for what you use, nothing more.

📜 License

MIT License