urchin mcp - Orinadus

Synopsis

urchin mcp

No flags. The server starts on stdin/stdout and runs until the parent process closes the pipe.

Protocol

JSON-RPC 2.0 over stdio. Each message is a newline-terminated JSON object. The server speaks the Model Context Protocol — IDEs that support MCP (Cursor, Zed, VS Code with the Copilot extension) can connect by launching this command as a subprocess.

Tools exposed

The server exposes 10 tools. See MCP Overview for the full list.

IDE configuration

VS Code / Copilot Chat
Cursor
Zed

Create .vscode/mcp.json in your workspace root:

{
  "servers": {
    "urchin": {
      "type": "stdio",
      "command": "urchin",
      "args": ["mcp"]
    }
  }
}

Restart VS Code. The MCP tools appear in Copilot Chat automatically.

Create or update .cursor/mcp.json at the repo root:

{
  "mcpServers": {
    "urchin": {
      "command": "urchin",
      "args": ["mcp"]
    }
  }
}

Cursor picks this up when you open the folder.

Add to ~/.config/zed/settings.json:

{
  "context_servers": {
    "urchin": {
      "command": {
        "path": "urchin",
        "args": ["mcp"]
      }
    }
  }
}

Requirements

urchin must be on PATH. Install via:

cargo install --path crates/urchin-cli

Or add ~/.cargo/bin to your PATH if you built locally.

Notes

The MCP server does not require urchin serve to be running. It reads and writes the journal file directly.
Each tool call reads the journal from disk. There is no in-memory cache between calls.
If the journal does not exist, query tools return empty results (not an error).
Errors from tool calls return isError: true in the MCP response envelope.

Urchin

Documentation Index

​Synopsis

​Protocol

​Tools exposed

​IDE configuration

​Requirements

​Notes