Use Stack Facts from Claude Code, Cursor or Codex (MCP)

Updated 2026-10-12. Stack Facts is an MCP server (Streamable HTTP) at https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp. No account and no API key: add the URL to your client and the tools appear.

Claude Code

claude mcp add --transport http stackfacts https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp

Or, for everyone on a project, in .mcp.json at the project root:

{
  "mcpServers": {
    "stackfacts": {
      "type": "http",
      "url": "https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp"
    }
  }
}

Cursor

In .cursor/mcp.json (one project) or ~/.cursor/mcp.json (every project):

{
  "mcpServers": {
    "stackfacts": {
      "url": "https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp"
    }
  }
}

Codex

codex mcp add stackfacts --url https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp

Or in ~/.codex/config.toml:

[mcp_servers.stackfacts]
url = "https://g5joilnmeep4ntz3nwezxt5dmu.srv.us/mcp"

What the tools do

• Free tools answer in the client: stackfacts_preview, stackfacts_try, stackfacts_index, stackfacts_validate, stackfacts_manifest, stackfacts_keys.
• Paid tools: stackfacts_eol_product, stackfacts_eol_cycle, stackfacts_eol_check, stackfacts_eol_image, stackfacts_eol_snapshot, stackfacts_kev_lookup, stackfacts_kev_check, stackfacts_kev_changes, stackfacts_kev_snapshot, stackfacts_models_lookup, stackfacts_models_estimate, stackfacts_models_cheapest, stackfacts_models_changes, stackfacts_models_snapshot, stackfacts_stack_check, stackfacts_osv_check, stackfacts_preflight, stackfacts_cve_lookup, stackfacts_stack_watch. Each answers with an x402 offer (isError) holding the price and the URL: send that HTTP request again with a PAYMENT-SIGNATURE header from any x402 v2 client to get the signed answer. MCP itself takes no payment.
• Every tool with its input schema and an example answer: llms-full.txt. The server card: /.well-known/mcp/server-card.json.

Data is provided as is, without warranty of any kind. Payments are final. Every dataset is normalised (modified) from the sources named here, and no source endorses this service.