Claude Code litmus check_server
How to: Claude Code litmus check_server
Add litmus to Claude Code
-
01
Run this in your project directory.
claude mcp add --transport http litmus https://polygraph.so/api/mcp-
02
Restart your session so the server is picked up.
-
03
Ask for something check_server does. Claude Code lists the server's tools on connect and calls check_server itself — you do not invoke it by name.
-
04
If nothing happens, check the server is running and that litmus's identifier in your config matches the one above exactly.
Adds it for this project only. Append --scope user to make it available everywhere. Claude Code 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.