Adopting the MCP Bundle format (.mcpb) for portable local servers

The MCP Bundle format (MCPB) is now part of the Model Context Protocol project. This distribution format simplifies how developers package and share local MCP servers, enabling users to install them across any compatible client, including the Claude desktop app, Claude Code, and MCP for Windows. What are MCP Bundles? MCP Bundles are ZIP archives containing a local MCP server and a manifest.json that describes the server and its capabilities. The format is similar to Chrome extensions (.crx) or VS Code extensions (.vsix), enabling end users to install local MCP servers with a single click. ...

November 21, 2025 · David Soria Parra (MCP Lead Maintainer), Joan Xie (MCPB Maintainer)

Server Instructions: Giving LLMs a user manual for your server

Many of us are still exploring the nooks and crannies of MCP and learning how to best use the building blocks of the protocol to enhance agents and applications. Some features, like Prompts, are frequently implemented and used within the MCP ecosystem. Others may appear a bit more obscure but have a lot of influence on how well an agent can interact with an MCP server. Server instructions fall in the latter category. ...

November 3, 2025 · Ola Hungerford (Maintainer)

Update on the Next MCP Protocol Release

Update (November 11, 2025): The specification release candidate (RC) date has been shifted from November 11th to November 14th, 2025. The specification release date remains to be November 25th, 2025. Release Timeline The next version of the Model Context Protocol specification will be released on November 25th, 2025, with a release candidate (RC) available on November 11th, 2025. We’re building in a 14-day RC validation window so client implementors and SDK maintainers can thoroughly test the protocol changes. This approach gives us the focused time we need to deliver critical improvements while applying our new governance model to the process. ...

September 26, 2025 · David Soria Parra

Introducing the MCP Registry

Today, we’re launching the Model Context Protocol (MCP) Registry—an open catalog and API for publicly available MCP servers to improve discoverability and implementation. By standardizing how servers are distributed and discovered, we’re expanding their reach while making it easier for clients to get connected. The MCP Registry is now available in preview. To get started: Add your server by following our guide on Adding Servers to the MCP Registry (for server maintainers) Access server data by following our guide on Accessing MCP Registry Data (for client maintainers) Single source of truth for MCP servers In March 2025, we shared that we wanted to build a central registry for the MCP ecosystem. Today we are announcing that we’ve launched https://registry.modelcontextprotocol.io as the official MCP Registry. As part of the MCP project, the MCP Registry, as well as a parent OpenAPI specification, are open source—allowing everyone to build a compatible sub-registry. ...

September 8, 2025 · David Soria Parra (Lead Maintainer), Adam Jones (Registry Maintainer), Tadas Antanavicius (Registry Maintainer), Toby Padilla (Registry Maintainer), Theodora Chu (MCP PM at Anthropic)

Announcing the Official PHP SDK for MCP

The official PHP SDK for the Model Context Protocol is now generally available. Built in collaboration with the PHP Foundation and Symfony, the PHP SDK handles protocol details, so developers don’t have to worry about low-level mechanics and can focus on building their applications. The initial release enables PHP developers to build MCP servers, exposing tools, prompts, and resources to AI applications. Support for PHP applications to act as MCP clients will follow. The PHP SDK now joins 9 other officially supported language SDKs in the MCP ecosystem, making it easier for developers everywhere to adopt MCP in their preferred language. ...

September 5, 2025 · David Soria Parra (Lead Maintainer), Christopher Hertel (Symfony), Roman Pronskiy (PHP Foundation)