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Shadow-cljs MCP Server

Monitors running shadow-cljs builds and exposes real-time build status updates to MCP clients.

Installation
Add the following to your MCP client configuration file.

Configuration

View docs
{
  "mcpServers": {
    "bigsy-shadow-cljs-mcp": {
      "command": "npx",
      "args": [
        "shadow-cljs-mcp"
      ]
    }
  }
}

This MCP server watches shadow-cljs builds and streams real-time status updates to clients. It helps you verify build progress, catch failures early, and see which files were compiled along with timing and metrics during development.

How to use

You run the MCP server locally and connect to it with an MCP client. After each edit to your ClojureScript files, you query the server to get the latest build status. The server reports whether the last build completed, failed, or is in progress, which files were involved, and any errors or warnings. Use this to quickly validate changes and iterate faster.

How to install

Prerequisites: Node.js and npm installed on your machine.

1) Install and run the MCP server using the local command shown here.

{
  "mcpServers": {
    "shadow_cljs_mcp": {
      "command": "npx",
      "args": [
        "shadow-cljs-mcp"
      ],
      "disabled": false,
      "autoApprove": [],
      "timeout": 60
    }
  }
}

Additional configuration and notes

If you want the server to listen on a specific host and port, you can provide optional arguments during startup. For example, you can run the MCP server on localhost:9630.

{
  "mcpServers": {
    "shadow_cljs_mcp": {
      "command": "npx",
      "args": [
        "shadow-cljs-mcp",
        "--host",
        "localhost",
        "--port",
        "9630"
      ],
      "disabled": false,
      "autoApprove": [],
      "timeout": 60
    }
  }
}

Security and usage notes

Ensure shadow-cljs is running before starting this MCP server. The server connects to a running shadow-cljs instance and reports build progress, failures, and completions to your MCP client.

Tools and endpoints you can use

The MCP server provides a tool you can call to verify the status of the last build after edits to ClojureScript files.

Available tools

get_last_build_status

Retrieves the latest shadow-cljs build status from the MCP server, including status (completed or failed), compiled files, duration, and any errors or warnings.