Ground Truth MCP

Let AI agents validate their own claims with real, live data from the web.

Live URL: https://ground-truth-mcp.anish632.workers.dev

🎯 What is Ground Truth?

Ground Truth is an MCP server that provides AI agents with fact-checking and market research tools. Instead of hallucinating or guessing, agents can:

• ✅ Check if an API endpoint actually exists

• 📊 Count real market competitors

• 💰 Extract actual pricing from websites

• 🔍 Compare packages side-by-side

• 🧪 Cross-reference claims against live sources

• ⚗️ Test hypotheses with structured tests

All results come from live data fetched in real-time, with 5-minute caching for performance.

🚀 Quick Start

Free Tier (No Signup)

Try the check_endpoint tool immediately:

curl -X POST https://ground-truth-mcp.anish632.workers.dev/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "check_endpoint",
      "arguments": {"url": "https://api.github.com"}
    },
    "id": 1
  }'

Pro Tier ($9/month)

1. Visit pricing page

2. Subscribe via Stripe

3. Get your API key: gt_live_...

4. Add to requests:

curl -X POST https://ground-truth-mcp.anish632.workers.dev/mcp \
  -H "X-API-Key: gt_live_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"estimate_market","arguments":{"query":"react","registry":"npm"}},"id":1}'

🛠️ Available Tools

Full API documentation: API_USAGE.md

💰 Pricing

Free Tier

• check_endpoint - Unlimited forever

Pro Tier - $9/month

• All 5 premium tools - Unlimited usage

• 5-minute caching - Fast responses

• 99.9% uptime SLA

• Cancel anytime - No questions asked

Subscribe now →

🏗️ Tech Stack

• Runtime: Cloudflare Workers (edge computing)

• Storage: Durable Objects with SQLite (caching + usage logs)

• API Keys: Cloudflare KV (encrypted at rest)

• Billing: Stripe Checkout + Subscriptions

• Protocol: Model Context Protocol (MCP)

• Language: TypeScript

📚 Documentation

• SETUP.md - Deployment & configuration guide

• API_USAGE.md - API reference & examples

• IMPLEMENTATION_SUMMARY.md - Implementation details

🔧 Development

Prerequisites

• Node.js 18+

• npm or pnpm

• Cloudflare account

• Stripe account

Local Setup

1. Clone the repo:

   cd "/Users/anishdas/Apps/Ground Truth/ground-truth-mcp"

2. Install dependencies:

   npm install

3. Create KV namespace:

   npx wrangler kv namespace create API_KEYS

4. Update wrangler.jsonc with KV namespace ID

5. Set secrets:

   npx wrangler secret put STRIPE_SECRET_KEY
   npx wrangler secret put STRIPE_WEBHOOK_SECRET

6. Run locally:

   npm start
   # or
   npx wrangler dev

7. Deploy:

   npm run deploy
   # or
   npx wrangler deploy

Full setup guide: SETUP.md

🧪 Testing

Test Free Tier (No Auth)

curl -X POST http://localhost:8787/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "check_endpoint",
      "arguments": {"url": "https://example.com"}
    },
    "id": 1
  }'

Test Auth Rejection

# Should return 402 (payment required)
curl -X POST http://localhost:8787/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "estimate_market",
      "arguments": {"query": "test", "registry": "npm"}
    },
    "id": 1
  }'

Test Stripe Checkout

1. Visit http://localhost:8787/pricing

2. Click "Subscribe Now"

3. Use test card: 4242 4242 4242 4242

4. Complete checkout

5. Verify API key displayed on success page

🔐 Security

• API Keys: Stored in Cloudflare KV (encrypted at rest)

• Stripe Keys: Stored as Worker secrets (encrypted)

• Webhook Validation: Signature verification (simplified for MVP)

• Key Revocation: Inactive keys marked on subscription cancellation

• Audit Trail: Keys not deleted, only marked inactive

🚦 Status & Monitoring

• Homepage: https://ground-truth-mcp.anish632.workers.dev

• Stats: https://ground-truth-mcp.anish632.workers.dev/stats

• Stripe Dashboard: https://dashboard.stripe.com

• Cloudflare Dashboard: https://dash.cloudflare.com

📊 Architecture

┌─────────────┐
│   User      │
└──────┬──────┘
       │
       ├─── Free Tier (no auth)
       │    └─► check_endpoint
       │
       ├─── Pro Tier (API key)
       │    ├─► X-API-Key header
       │    ├─► Validate against KV
       │    └─► estimate_market, check_pricing, etc.
       │
       └─── x402 (fallback)
            └─► Crypto payment for single call
       
┌─────────────────────────────────────┐
│   Cloudflare Worker                  │
├─────────────────────────────────────┤
│  ┌──────────────┐  ┌──────────────┐ │
│  │ Auth         │  │ Stripe       │ │
│  │ Middleware   │  │ Integration  │ │
│  └──────────────┘  └──────────────┘ │
│         │                 │          │
│  ┌──────▼──────┐  ┌──────▼────────┐ │
│  │ KV Store    │  │ Durable       │ │
│  │ (API Keys)  │  │ Objects       │ │
│  └─────────────┘  │ (Cache+Logs)  │ │
│                   └───────────────┘ │
└─────────────────────────────────────┘

🤝 Contributing

Not accepting external contributions at this time (private project), but feel free to fork for your own use.

📜 License

MIT License - see LICENSE file for details

🆘 Support

• Email: anishdasmail@gmail.com

• Issues: https://github.com/anish632/ground-truth-mcp/issues

• Twitter: @anish632

🎯 Use Cases

For AI Agents

• Validate market research before presenting findings

• Fact-check claims against live sources

• Compare competitors with real data

• Test hypotheses with structured verification

For Developers

• Pre-validate APIs before recommending them

• Check pricing without manual web scraping

• Estimate package counts for market sizing

• Automated fact-checking in CI/CD

For Researchers

• Cross-reference claims with live data

• Track package versions over time

• Monitor pricing changes

• Validate academic hypotheses

🏆 What Makes Ground Truth Different?

✅ Live Data: No stale databases, all results from real-time fetching
✅ Caching: 5-minute cache for performance without sacrificing freshness
✅ MCP Native: Built for AI agents from day one
✅ Edge Computing: Fast responses from Cloudflare's global network
✅ Free Tier: No credit card required to try it
✅ Transparent Pricing: $9/month, unlimited usage, no hidden fees
✅ x402 Fallback: Pay-per-call with crypto if you don't want a subscription

📈 Roadmap

• Core fact-checking tools

• Stripe billing integration

• API key authentication

• Free tier (check_endpoint)

• Webhook handling for subscriptions

• Usage analytics dashboard

• Email notifications

• Team accounts

• Enterprise tier

• Custom integrations

🙏 Acknowledgments

• Built with MCP SDK

• Powered by Cloudflare Workers

• Payments by Stripe

• x402 integration by @x402

Made with ❤️ by Anish Das

Last updated: March 20, 2026