Gemini CLI costheta costheta_witness

How to: Gemini CLI costheta costheta_witness

client:Gemini CLI transport:streamable-http tool:costheta_witness

Add costheta to Gemini CLI

01
Open ~/.gemini/settings.json and merge this in. Keep any servers already there.

{
  "mcpServers": {
    "costheta": {
      "httpUrl": "https://costheta.dev/mcp"
    }
  }
}

02
Save the file and restart Gemini CLI.
03
Ask for something costheta_witness does. Gemini CLI lists the server's tools on connect and calls costheta_witness itself — you do not invoke it by name.
04
If nothing happens, check the server is running and that costheta's identifier in your config matches the one above exactly.

Gemini expands $VAR and ${VAR} inside env values, so a secret can live in your shell rather than this file. Gemini CLI docs

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.

costheta MCP server