Unified MCP Server Plugin for JavaScript Build Tools

Overview

The Unified MCP Server Plugin is a versatile tool designed to integrate the Model Context Protocol (MCP) with various JavaScript build tools such as Rollup, Vite, Webpack, and more. This plugin creates and manages an MCP server, enabling AI assistants to interact with your codebase, build tools, and even control the build process. It provides a unified interface for MCP clients, making it easier to integrate AI capabilities into your development workflow.

Features

• Cross-Platform MCP Integration: Seamlessly integrates with multiple build tools.
• Bi-directional AI Integration: Allows AI to both understand and modify your build process.
• Rich Built-in Tools: Includes tools for analyzing module dependencies, inspecting build configurations, and debugging errors.
• Extensible Tool Framework: Enables the creation of custom MCP tools.
• Build Process Integration: Hooks into the build process at any point.
• Persistent Server: Continues running in watch mode for continuous AI interaction.
• Standard Transport Layer: Uses HTTP and Server-Sent Events (SSE) for compatibility.

Installation

To install the plugin, run the following command:

# Install the plugin
pnpm add -D unplugin-mcp

# Or install a bundler-specific version
pnpm add -D rollup-plugin-mcp

Usage

Build Tool Integration

Here’s an example of how to use the plugin with Rollup:

// rollup.config.js
import { defineConfig } from 'rollup';
import { rollupPlugin as mcp } from 'unplugin-mcp';
import { ModuleTool, BuildConfigTool, BuildErrorTool } from 'unplugin-mcp/tools';

export default defineConfig({
  plugins: [
    mcp({
      provideUnpluginMcpTools: () => [
        new ModuleTool(),
        new BuildConfigTool(),
        new BuildErrorTool()
      ]
    }),
  ]
});

Usage in Cursor

To integrate with Cursor, add the MCP server to your Cursor settings:

{
  "mcpServers": {
    "rollup": {
      "url": "http://localhost:14514/mcp/sse"
    }
  }
}

Options

For all available options, refer to the McpPluginOptions in the types file.

Built-in Tools Compatibility

Custom Tools

You can extend the plugin with custom tools by implementing the UnpluginMcpTool interface:

import { InputOptions } from "rollup";
import { UnpluginMcpTool, UnpluginMcpToolSetupOptions } from "unplugin-mcp";
import DeferredCtor, { Deferred } from 'promise-deferred';
import { UnpluginOptions } from "unplugin";

export class BuildConfigTool implements UnpluginMcpTool {
  private buildConfig: Deferred<InputOptions>;

  affectsBuildProcess: boolean = false;

  constructor() {
    this.buildConfig = new DeferredCtor<InputOptions>();
  }

  setupMcpServer(mcpServer: any, options?: any) {
    mcpServer.tool(
      `get-build-config`,
      "Get build configuration",
      {},
      async () => {
        const cfg = await this.buildConfig.promise;
        return {
          content: [
            {
              type: 'text',
              text: `Build configuration: ${JSON.stringify(cfg)}`
            }
          ]
        };
      }
    );
    return mcpServer;
  }

  registerPlugins(options?: UnpluginMcpToolSetupOptions): UnpluginOptions {
    let self = this;
    return {
      name: 'build-config-tool',
      rollup: {
        options(config) {
          self.buildConfig.resolve(config);
        }
      }
    }
  }
}

Register the custom tool in your Rollup config:

// rollup.config.js
plugins: [
  mcp({
    provideUnpluginMcpTools: () => [
      new BuildConfigTool()
    ]
  })
]

Examples

Check out the examples directory for working examples.

How It Works

1. Creates and sets up a singleton MCP server instance.
2. Registers UnpluginMcpTool instances to the MCP server.
3. Creates an HTTP server and sets up HTTP routes for the MCP server.
4. Starts the HTTP server, listening on the specified port and host.
5. Registers hooks created by UnpluginMcpTool instances to build tools.

License

MIT License. Copyright (c) 2025 situ2001.

About

A unified MCP (Model Context Protocol) server plugin for any JavaScript build tools.

Topics

• mcp
• rollup
• rollup-plugin
• unplugin
• mcp-server
• modelcontextprotocol

Resources

• Readme
• License

Contributors

• situ2001
• github-actions[bot]

Languages

• TypeScript 89.3%
• JavaScript 10.7%