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MCP Bundles

open source / Overall score: 3.0

A packaging format for local MCP servers: a zip archive carrying the server and a manifest describing it, so a desktop application can install one in a single click. Ships the bundle specification, a CLI that builds bundles, and the loader desktop clients use to verify them.

Two things a reader will otherwise trip over. The project is mid-rename from DXT (Desktop Extensions) to MCPB (MCP Bundles) - the CLI and the npm package both moved, and the GitHub description still says Desktop Extensions - and its README still points at the old `anthropics/mcpb` URLs rather than the `modelcontextprotocol` org it now lives in. It is also the least recently pushed record in this category, at 2026-05-26.

Openness

5 high confidence

5.0

license: Apache-2.0(OSI
source: public(the bundle specification, the CLI and the loader)
self-host: yes(the specification and its SDK are the product)
core features withheld: no — nothing withheld

Open source under the MCP project's dual transition licence, with the body cited because the classifier reports NOASSERTION over it.

https://api.github.com/repos/modelcontextprotocol/mcpb recorded 2026-09-17
Repository metadata: 2,112 stars, not archived, not a fork, last pushed 2026-05-26, description "Desktop Extensions: One-click local MCP server installation in desktop apps" - the pre-rename name.
https://raw.githubusercontent.com/modelcontextprotocol/mcpb/main/LICENSE recorded 2026-09-17
The LICENSE body, read rather than the classifier's label: the MCP project's licensing transition file, Apache-2.0 for new contributions with MIT retained where consent was not given. That shape is why the API reports NOASSERTION.

Adoption

3 medium confidence

3.0

Adoption is measured as npm downloads of `@anthropic-ai/mcpb`. The package is mid-rename from `@anthropic-ai/dxt`, so installs may still be split across the two names and this count reflects only the new one.

https://api.npmjs.org/downloads/point/last-month/@anthropic-ai/mcpb recorded 2026-09-17
npm downloads point API: 261,250 downloads for `@anthropic-ai/mcpb` over 2026-08-13 to 2026-09-11.

Capability

not assessed

MCP Bundles is a packaging format, not a client or server, so it implements no role, primitive or transport for the protocol itself. It describes how a server is shipped and installed - zip archives containing a local MCP server and a manifest.json - and its only mention of the protocol tells bundle authors to implement it themselves, a requirement it places on others rather than one it meets.

https://raw.githubusercontent.com/modelcontextprotocol/mcpb/main/README.md recorded 2026-09-17
The README: "MCP Bundles (.mcpb) are zip archives containing a local MCP server and a manifest.json that describes the server and its capabilities. The format is spiritually similar to Chrome extensions (.crx) or VS Code extensions (.vsix), enabling end users to install local MCP servers with a single click." It ships "the bundle specification in MANIFEST.md, a CLI tool for creating bundles ... and the code used by Claude for macOS and Windows to load and verify MCPB bundles", and carries the DXT-to-MCPB rename notice.

Verified 2026-09-17