We’re updating how Specification Enhancement Proposals (SEPs) are submitted and managed. Starting today, SEPs will be created as pull requests to the seps/ directory instead of GitHub issues. Why the Change? When we introduced SEPs in July, we chose GitHub Issues as our starting point. Issues are familiar to developers, low-friction, and got us up and running quickly. But as more proposals have come through the process, we’ve identified some key pain points: ...

Today, MCP turns one year old. You can check out the original announcement blog post if you don’t believe us. It’s hard to imagine that a little open-source experiment, a protocol to provide context to models, became the de-facto standard for this very scenario in less than twelve months. But not only do we hit the first anniversary milestone today - we’re also releasing a brand-new MCP specification version. Before we get to the details of what’s new, let’s do a bit of a retrospective. ...

Today we’re introducing the proposal for the MCP Apps Extension (SEP-1865) to standardize support for interactive user interfaces in the Model Context Protocol. This extension addresses one of the most requested features from the MCP community and builds on proven work from MCP-UI and OpenAI Apps SDK - the ability for MCP servers to deliver interactive user interfaces to hosts. MCP Apps Extension introduces a standardized pattern for declaring UI resources, linking them to tools, and enabling bidirectional communication between embedded interfaces and the host application. ...

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. ...

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. ...