Skip to content

Grok litmus check_server

How to: Grok litmus check_server

client:Grok transport:streamable-http tool:check_server

Add litmus to Grok

  1. 01

    Open .mcp.json (in your project root) and merge this in. Keep any servers already there.

{
  "mcpServers": {
    "litmus": {
      "type": "http",
      "url": "https://polygraph.so/api/mcp"
    }
  }
}
  1. 02

    Save the file and restart Grok.

  2. 03

    Ask for something check_server does. Grok lists the server's tools on connect and calls check_server itself — you do not invoke it by name.

  3. 04

    If nothing happens, check the server is running and that litmus's identifier in your config matches the one above exactly.

Grok Build reads Claude Code's .mcp.json and Claude Desktop's config unchanged, so a server you have already set up there needs nothing new. The Grok web app and X integration do not take custom servers. Grok docs

Set these first

litmus will not start until these are set, so check_server never becomes available.

  • POLYGRAPH_API_URL
  • NEXT_PUBLIC_POLYGRAPH_NETWORK

Same tool, other clients

This list was read from the server itself, by connecting to it and calling tools/list on 24 September 2026. It is what the server actually exposes, not what its listing claims.

Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.