⚡ Datomic MCP Server

AI. Query. Persist. Extend.
A robust Clojure-based MCP server designed for querying Datomic databases and integrating with AI-powered workflows.

🔍 Key Features

🗄️ Connect to Datomic (SQL / Dev / Cloud)

• Seamlessly connect to your Datomic database and run queries directly from AI workflows.
• Works with Datomic Pro (SQL, Dev-local) and Datomic Cloud setups.

📂 Query entity relationships

📊 Aggregate queries & computations

🧾 Entity properties and history

• Explore entity attributes
• Query temporal history (as-of, since)
• Transaction-time navigation

⚙️ Getting Started

▶️ Run the MCP Server

Run with Clojure CLI:

clojure -X:mcp

Or from Emacs REPL:

(mcp-server)

✅ Check Server Health

Use the following command to verify the MCP server is up and responding to JSON-RPC:

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 datomic-mcp.core

Expected response:

Datomic MCP Server running on STDIO transport.
{"jsonrpc":"2.0","method":"notifications/tools/list_changed"}
...
{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2024-11-05","capabilities":{"logging":{},"tools":{"listChanged":true}},"serverInfo":{"name":"datomic-server","version":"0.1.0"}}}

🖥️ MCP Client Configuration (Claude Desktop)

Example client setup for launching the server from Claude Desktop:

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

...

}

• Tools

🔮 Roadmap

inspired by https://github.com/xlisp/datascript-mcp-server

1. Query live Datomic databases 👉 connect to SQL / Dev-local / Cloud
2. Hybrid queries across Datomic + DataScript 👉 offline + persistent data https://github.com/xlisp/datascript-mcp-server
3. Visualize Datomic relationships 👉 Visualization MCP Server
4. Import/export datasets 👉 transit, edn, or AI-generated inserts
5. Filesystem MCP integration 👉 browse schema & migrations https://github.com/xlisp/filesystem-mcp-server
6. Support Datomic history queries 👉 temporal navigation (as-of, since, history)

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

FQA

change list

• [x] Datomic in-memory database already supports
• [x] Connect any Datomic database url

Run in JDK 17 (datomic client)

export JAVA_HOME="/Library/Java/JavaVirtualMachines/microsoft-17.jdk/Contents/Home" #'/Library/Java/JavaVirtualMachines/microsoft-11.jdk/Contents/Home'
export PATH=$JAVA_HOME/bin:$PATH
export CPPFLAGS="-I/Library/Java/JavaVirtualMachines/microsoft-17.jdk/Contents/Home/include"

Run datomic transactor

• datomic-pro-1.0.6165 transactor must run on java 1.8 ( brew install openjdk@8 ), other jdk will errors Execution error (ActiveMQInternalErrorException) at org.apache.activemq.artemis.core.protocol.core.impl.ChannelImpl/sendBlocking (ChannelImpl.java:404).

➜  datomic-pro-1.0.6165 ./rundatomic.sh
Launching with Java options -server -Xms4g -Xmx4g -XX:+UseG1GC -XX:MaxGCPauseMillis=50
Starting datomic:sql://<DB-NAME>?jdbc:postgresql://localhost:5432/db123123?user=postgres&password=123456, you may need to change the user and password parameters to work with your jdbc driver ...

Built with Clojure. Powered by Datomic. Inspired by the future of persistent querying. In the Source we trust.