Which integrations are available for this server?

Allows for querying the npm registry to count packages, retrieve version history, and analyze activity signals to verify market competition and software availability. Enables searching the PyPI registry to count packages and assess market presence by checking update history and activity signals.

Ground Truth MCP Server

Validate AI claims against live data.

An MCP server that lets AI agents fact-check their own research in real time — probing endpoints, counting competitors, and testing hypotheses against live registries instead of guessing.

Origin

This tool was born from an AI agent catching itself giving bad advice. During a research conversation about MCP business opportunities, the agent recommended building products based on claims like "competition is low" and "this API is freely available" — then built a prototype to test those claims and discovered several were wrong. Competitors it said didn't exist already had packages on npm. An API it recommended building on top of couldn't even be reached.

Ground Truth is the tool that conversation needed.

Tools

`check_endpoint`

Probe a URL or API endpoint. Returns HTTP status, content type, response time, auth requirements, rate limit headers, and a structural summary of the response.

"Is this API actually accessible, or am I recommending something that doesn't work?"

`estimate_market`

Count packages/servers in a space on npm or PyPI. Returns total count, top results with version history and update dates, and activity signals.

"I'm about to say 'competition is low' — is that actually true?"

`test_hypothesis`

Test a factual claim against multiple live checks. Returns pass/fail per test and an overall verdict: SUPPORTED, REFUTED, or PARTIALLY SUPPORTED.

"Before I present this conclusion, let me verify it."

Connect

MCP Inspector (quickest test)

npx @modelcontextprotocol/inspector@latest # Enter: https://ground-truth-mcp.<your-subdomain>.workers.dev/mcp

Claude Desktop

Add to claude_desktop_config.json:

{ "mcpServers": { "ground-truth": { "url": "https://ground-truth-mcp.<your-subdomain>.workers.dev/mcp" } } }

Any MCP Client

Connect to https://ground-truth-mcp.<your-subdomain>.workers.dev/mcp via Streamable HTTP transport.

Develop

npm install npm start # local dev server at http://localhost:8787/mcp npm run deploy # deploy to Cloudflare Workers

What It Caught (First Run)

Claim	Verdict
"Memory MCP server competition is Medium"	⚠️ Medium but actively growing — 12+ packages, several updated this week
"Email/SMS MCP servers: very low competition"	❌ Wrong — `twilio-mcp` and `mcp-send-email` already exist
"Business verification MCP space is empty"	✅ Confirmed — no relevant packages found
"OpenCorporates has a free API"	❌ Could not verify — API unreachable