Claude Desktop extension (.mcpb)

scripts/pack-mcpb.ps1 builds a win32 .mcpb into dist/ (gitignored). build-windows.bat runs that script after the server build. Output name: dist/filesystem-ultra-<version>-win32.mcpb. The manifest version is 4.8.0.

The bundle is Windows only. Double-click the .mcpb in Claude Desktop. The install dialog asks for allowed directories. The server exits if none are set. Copying the file into the extension directory is a manual step.

bundle/manifest.json starts the binary with:

--profile strict --compact-mode --roots-mode union --log-level error

plus the directories chosen in the dialog (user_config.allowed_directories, required, multiple).

The entry point inside the bundle is server/filesystem-ultra.exe. The canonical name is filesystem-ultra, not mcp-filesystem-server-ultra.

The bundle does not implement MCP 2026-07-28.