Datascript

The Datascript MCP is a Clojure-based MCP server that exposes a local DataScript database to any MCP client.

It acts as a translator that lets your AI assistants run complex queries against your in-memory DataScript data.

This can be useful for AI-driven workflows where you need to ground a model’s responses with specific, structured data you have on your machine.

Features

• 🕸️ Graph Visualization: Search graph paths and visualize the results by connecting to a visualization server.
• 📂 Hierarchical Queries: Easily query parent-child relationships within your datasets.
• 📊 On-the-fly Computations: Load example data and calculate totals directly through queries.
• 🧾 Entity Inspection: Retrieve specific properties from any entity in your database.

Use Cases

• AI-Assisted Data Analysis: Pose natural language questions to an AI client about a local DataScript database. For instance, you could ask, “Show all active projects and their due dates,” and get a structured answer directly from your data.
• Interactive Knowledge Graphs: Model a personal knowledge base in DataScript and use this server with a visualization tool. This setup lets you visually explore connections and relationships between your notes and ideas.
• Rapid Prototyping: Quickly test application ideas that depend on complex data queries without the overhead of a full database and API stack. It’s an effective way to work with graph-like data on your local machine.

How to Use It

1. To get started, make sure you have the Clojure command-line interface installed.

2. Run the MCP server:

clojure -X:mcp

3. If you are working from an Emacs REPL, you can start the server with:

(mcp-server)

4. You can check if the server is running correctly by sending it a JSON-RPC request. This command pipes an initialize message to the server, which communicates over standard input and output (STDIO).

echo '{"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {"protocolVersion": "2024-11-05", "capabilities": {}, "clientInfo": {"name": "test", "version": "1.0"}}}' \
| /usr/local/bin/clojure -M -m datascript-mcp.core

A successful response confirms the server is active and returns its capabilities.

5. To connect a MCP client like Claude Desktop, you need to add a configuration that tells the application how to launch the server. You can do this by editing the claude_desktop_config.json file.

Here is an example configuration:

{
  "datascript-mcp": {
    "command": "/bin/bash",
    "args": [
      "-c",
      "cd /Users/clojure/Desktop/datascript-mcp-server && /usr/local/bin/clojure -M -m datascript-mcp.core"
    ]
  }
}

This JSON object instructs Claude Desktop to change to the server’s directory and then execute the launch command. After restarting the desktop application, the server’s tools should become available.

FAQs

Q: Does the server store my data permanently?
A: No, the Datascript MCP Server operates on an in-memory DataScript database. Data must be loaded for each session.

Q: What does “STDIO transport” mean?
A: It means the server communicates using Standard Input (STDIN) for receiving commands and Standard Output (STDOUT) for sending responses. This is a straightforward method for local inter-process communication.

Q: Can this be used with clients other than Claude Desktop?
A: Yes. Any MCP client that can execute a shell command and communicate over STDIN/STDOUT using the JSON-RPC format should be compatible.