FactStamp MCP

FactStamp provides an MCP server for verifying factual claims, legal entities, citations, and software packages. It offers tools to check dated figure claims, validate company identities against official registers, verify academic citations, and check software package statuses. The service provides cited verdicts (verified, stale, contradicted, unknown) and operates on a pay-per-use model via x402.

Endpoint and access

No sign-in: your client connects and lists tools immediately, with no account or key.

No sign-inEndpoint checked 2026-10-19Operated by FactStamp

MCP endpoint (Streamable HTTP)

https://agents.factstamp.dev/mcp

Vendor documentation

What you can do with it

Verify dated figure claims against primary sources
Check legal entity identity and registration status
Verify academic citations from DOI or arXiv
Check software package version existence and advisories

Tools advertised by the last live check:

list_series
route_claim
list_card_packages
buy_card_package
check_figure
check_entity
check_entity_file
check_sanctions
check_vat
verify_citation
verify_package
watch_add
watch_portfolio
verify_bulk
check_document

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers a Streamable HTTP server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport http factstamp-mcp https://agents.factstamp.dev/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).

Codex configuration

codex mcp add factstamp-mcp --url https://agents.factstamp.dev/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable factstamp-mcp in your MCP settings.

Cursor configuration

{
  "mcpServers": {
    "factstamp-mcp": {
      "url": "https://agents.factstamp.dev/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure). The type must be streamableHttp for a remote HTTP server.

Cline configuration

{
  "mcpServers": {
    "factstamp-mcp": {
      "type": "streamableHttp",
      "url": "https://agents.factstamp.dev/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start factstamp-mcp and inspect its tools.

VS Code configuration

{
  "servers": {
    "factstamp-mcp": {
      "type": "http",
      "url": "https://agents.factstamp.dev/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport http factstamp-mcp https://agents.factstamp.dev/mcp

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.

Claude Desktop configuration

{
  "mcpServers": {
    "factstamp-mcp": {
      "url": "https://agents.factstamp.dev/mcp"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.

Windsurf configuration

{
  "mcpServers": {
    "factstamp-mcp": {
      "serverUrl": "https://agents.factstamp.dev/mcp"
    }
  }
}

See all 2,103

Do you run FactStamp MCP?

Prove ownership with a DNS record, a well-known file, or your Official MCP Registry entry, and your edits publish immediately. Proofs are re-checked weekly; admins can still hide or remove a listing.

Claim this listing