MCP Bundler

A tool for bundling Smithery MCP servers into MCPB (MCP Bundle) format for easy distribution and deployment.

Features

• Smithery Integration: Reads smithery.yaml configuration files
• MCPB Compliance: Generates MCPB-compliant bundles with proper manifest
• Smart Configuration: Converts Smithery config schemas to MCPB user config format
• Type Safety: Proper JSON Schema to MCPB type mapping
• Nested Config Support: Flattens nested configurations using dot notation
• Automatic Detection: Smart entry point detection and TypeScript support
• Optimized Builds: Minification, tree-shaking, and Node.js built-in externals

Installation

npm install @mcps/bundler

Or use directly:

npx @mcps/bundler <project-name>

Usage

CLI

# Bundle a project
mcp-bundler mcp-shrimp-task-manager

# With options
mcp-bundler my-server --minify=false --entry=src/main.ts

Programmatic API

import { bundleMCPServer } from '@mcps/bundler';

const result = await bundleMCPServer(
  '/path/to/project',
  '/path/to/output',
  {
    minify: true,
    entry: 'src/index.ts'
  }
);

console.log(`Bundle created: ${result.outputDir} (${result.bundleSize}KB)`);

Configuration

The bundler reads smithery.yaml files and converts them to MCPB format:

Input (smithery.yaml)

startCommand:
  configSchema:
    type: object
    properties:
      dataDir:
        type: string
        description: Directory for data storage
      auth:
        type: object
        properties:
          apiKey:
            type: string
            description: API key for authentication
    required: [dataDir]

Output (manifest.json)

{
  "manifest_version": "0.2",
  "name": "my-server",
  "version": "1.0.0",
  "user_config": {
    "dataDir": {
      "type": "directory",
      "title": "Data Dir",
      "description": "Directory for data storage",
      "required": true
    },
    "auth.apiKey": {
      "type": "string",
      "title": "Auth API Key",
      "description": "API key for authentication",
      "sensitive": true
    }
  },
  "server": {
    "type": "node",
    "entry_point": "server.cjs",
    "mcp_config": {
      "command": "node",
      "args": ["${__dirname}/server.cjs"],
      "env": {
        "DATADIR": "${user_config.dataDir}",
        "AUTH_API_KEY": "${user_config.auth.apiKey}"
      }
    }
  }
}

Features

Smart Type Conversion

• Automatically detects directory/path fields
• Maps JSON Schema types to MCPB types
• Handles sensitive fields (passwords, keys, tokens)
• Supports validation constraints (min/max for numbers)

Dot Notation Flattening

• Converts nested objects to flat dot notation
• auth.apiKey becomes AUTH_API_KEY environment variable
• Generates user-friendly titles: auth.apiKey → "Auth API Key"

Build Optimization

• Minification enabled by default
• Tree-shaking for smaller bundles
• Node.js built-ins marked as external
• TypeScript support with automatic tsconfig detection

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | minify | boolean | true | Enable minification | | entry | string | auto-detect | Override entry point |

Output Structure

project-name.mcpb/
├── server.cjs      # Bundled executable server
└── manifest.json   # MCPB manifest with metadata

API Reference

bundleMCPServer(projectPath, outputDir, options)

Bundles an MCP server project.

Parameters:

• projectPath (string): Path to the project directory
• outputDir (string): Output directory for the bundle
• options (object): Bundle options

Returns: Promise resolving to bundle result with outputDir, bundleSize, and warnings.

parseSmitheryYaml(yamlContent)

Parses Smithery YAML configuration.

smitheryConfigToUserConfig(configSchema)

Converts Smithery config schema to MCPB user config format.

smitheryToManifest(smitheryConfig, packageInfo)

Generates MCPB manifest from Smithery config and package info.

Requirements

• Node.js >= 18.0.0
• Valid smithery.yaml configuration file
• Valid package.json in project root

License

MIT