Motherduck MCP server

DuckDB / MotherDuck Local MCP Server

SQL analytics and data engineering for AI Assistants and IDEs.

Connect AI assistants to your data using DuckDB's powerful analytical SQL engine. Supports connecting to local DuckDB files, in-memory databases, S3-hosted databases, and MotherDuck. Allows executing SQL read- and write-queries, browsing database catalogs, and switching between different database connections on-the-fly.

Looking for a fully-managed remote MCP server for MotherDuck? → Go to the MotherDuck Remote MCP docs

Remote vs Local MCP

📝 Migrating from v0.x?

- Read-only by default: The server now runs in read-only mode by default. Add --read-write to enable write access. See Securing for Production.

- Default database changed: --db-path default changed from md: to :memory:. Add --db-path md: explicitly for MotherDuck.

- MotherDuck read-only requires read-scaling token: MotherDuck connections in read-only mode require a read-scaling token. Regular tokens require --read-write.

Quick Start

Prerequisites: Install uv via pip install uv or brew install uv

Connecting to In-Memory DuckDB (Dev Mode)

{
  "mcpServers": {
    "DuckDB (in-memory, r/w)": {
      "command": "uvx",
      "args": ["mcp-server-motherduck", "--db-path", ":memory:", "--read-write", "--allow-switch-databases"]
    }
  }
}

Full flexibility with no guardrails — read-write access and the ability to switch to any database (local files, S3, or MotherDuck) at runtime.

Connecting to a Local DuckDB File in Read-Only Mode

{
  "mcpServers": {
    "DuckDB (read-only)": {
      "command": "uvx",
      "args": ["mcp-server-motherduck", "--db-path", "/absolute/path/to/your.duckdb"]
    }
  }
}

Connects to a specific DuckDB file in read-only mode. Won't hold on to the file lock, so convenient to use alongside a write connection to the same DuckDB file. You can also connect to remote DuckDB files on S3 using s3://bucket/path.duckdb — see Environment Variables for S3 authentication. If you're considering third-party access to the MCP, see Securing for Production.

Connecting to MotherDuck in Read-Write Mode

{
  "mcpServers": {
    "MotherDuck (local, r/w)": {
      "command": "uvx",
      "args": ["mcp-server-motherduck", "--db-path", "md:", "--read-write"],
      "env": {
        "motherduck_token": "<YOUR_MOTHERDUCK_TOKEN>"
      }
    }
  }
}

See Command Line Parameters for more options, Securing for Production for deployment guidance, and Troubleshooting if you encounter issues.

Client Setup

Shortened. The full README is on GitHub.