Thebrain MCP Server

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add thebrain -e 'THEBRAIN_API_KEY=<THEBRAIN_API_KEY>' -- npx -y thebrain-mcp-server

{
  "mcpServers": {
    "thebrain": {
      "command": "npx",
      "args": [
        "-y",
        "thebrain-mcp-server"
      ],
      "env": {
        "THEBRAIN_API_KEY": "<THEBRAIN_API_KEY>"
      }
    }
  }
}

[mcp_servers.thebrain]
command = "npx"
args = ["-y", "thebrain-mcp-server"]
env = { THEBRAIN_API_KEY = "<THEBRAIN_API_KEY>" }

{
  "mcpServers": {
    "thebrain": {
      "command": "npx",
      "args": [
        "-y",
        "thebrain-mcp-server"
      ],
      "env": {
        "THEBRAIN_API_KEY": "<THEBRAIN_API_KEY>"
      }
    }
  }
}

{
  "servers": {
    "thebrain": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "thebrain-mcp-server"
      ],
      "env": {
        "THEBRAIN_API_KEY": "<THEBRAIN_API_KEY>"
      }
    }
  }
}

Put your own value in place of <THEBRAIN_API_KEY> (Local API key from TheBrain: Settings > User > Local API Key). The author’s registry entry marks it as required.

Optional settings from the registry entry, left out of the block above: THEBRAIN_BASE_URL (Address of the local API. Default http://localhost:11522, then http://localhost:8001 for older TheBrain builds), THEBRAIN_DATA_DIR (Where semantic indexes are stored. Default ~/.thebrain-mcp), THEBRAIN_ALLOW_DESTRUCTIVE (Set to 1 to allow deleting thoughts. Deletion still requires human confirmation. Default 0), THEBRAIN_EMBEDDING_MODEL (Embedding model for semantic search. Default Xenova/multilingual-e5-small), THEBRAIN_EMBEDDING_DTYPE (Weight precision: fp32, fp16, q8 or q4. Default q8), THEBRAIN_TIMEOUT_MS (API request timeout in milliseconds. Default 30000).