build-mcpb

# Build an MCPB (Bundled Local MCP Server) MCPB is a local MCP server **packaged with its runtime**. The user installs one file; it runs without needing Node, Python, or any toolchain on their machine. It's the sanctioned way to distribute local MCP servers. > MCPB is the **secondary** distribution path. Anthropic recommends remote MCP servers for directory listing — see https://claude.com/docs/connectors/building/what-to-build. **Use MCPB when the server must run on the user's machine** — reading local files, driving a desktop app, talking to localhost services, OS-level APIs. If your server only hits cloud APIs, you almost certainly want a remote HTTP server instead (see `build-mcp-server`). Don't pay the MCPB packaging tax for something that could be a URL. --- ## What an MCPB bundle contains ``` my-server.mcpb (zip archive) ├── manifest.json ← identity, entry point, config schema, compatibility ├── server/ ← your MCP server code │ ├── index.js │ └── node_modules/ ← bundled dependencies (or vendored) └── icon.png ``` The host reads `manifest.json`, launches `server.mcp_config.command` as a **stdio** MCP server, and pipes messages. From your code's perspective it's identical to a local stdio server — the only difference is packaging. --- ## Manifest ```json { "$schema": "https://raw.githubusercontent.com/anthropics/mcpb/main/schemas/mcpb-manifest-v0.4.schema.json", "manifest_version": "0.4", "name": "local-fil...