mcpb

MCPB is a bundle tool for creating and installing local MCP servers as MCP Bundles (.mcpb). The repository provides a CLI that helps you generate a manifest.json and package a local server into a single .mcpb file, making it easy for desktop applications to discover, install, and configure local MCP servers. With MCPB, you can build bundles for Node.js, Python, or other environments by including the server code and dependencies inside the bundle, along with a manifest describing the server's capabilities and configuration options. The CLI guides you through the manifest creation process and bundle packing, and it supports both creating new bundles and validating their structure against the MCP Bundle specification.

To get started, install the MCPB CLI, initialize a bundle in your server directory, and then pack it into a .mcpb file. Applications that support MCPB can then present users with a one-click installation experience that wires up environment variables, server entry points, and tools exposed by your server.

Prerequisites:

• Node.js and npm installed on your system
• Basic familiarity with your local MCP server code and its entry point

Install the MCPB CLI globally:

npm install -g @anthropic-ai/mcpb

Create a new bundle from your existing MCP server folder:

cd /path/to/your/server
mcpb init

This step will guide you through creating the manifest.json with required and optional fields.

Pack the bundle into an .mcpb file:

mcpb pack

The resulting bundle.mcpb file can be distributed and installed by applications that support MCP Bundles. For further customization, edit manifest.json to configure server metadata, tools, and environment variables as described in MANIFEST.md.

Tips and considerations:

• Ensure your server’s entry point and tools are clearly defined in manifest.json under the server section.
• Include all necessary dependencies inside the bundle (for Node.js bundles, that means node_modules; for Python bundles, include lib or venv as needed).
• Validate the bundle against the MCP Bundle spec and test installation with a supported host application to catch issues early.
• If your server requires environment variables, document them in manifest.json and provide sensible defaults or placeholders in the bundle for easier setup.
• MCPB bundles are designed for local installation and discovery by desktop applications; keep paths and resources self-contained within the bundle to maximize portability.