What Gofastmcp changed

• Added support for "Modern" vs "Legacy" protocol eras (v4.0.0).
• Introduced a new response caching system for tools and resources to reduce network lag.
• Added "Client Extensions" to support non-standard vendor features.
• Added configuration-based client creation (v2.4.0) compatible with Claude Desktop.
• Expanded documentation for specific use cases like AI agents, testing, and "skills" discovery.
• Removed high-level marketing content about "Prefect Horizon" in favor of deep technical client documentation.

The framework is moving from a simple server builder to a complex client-side manager. It now handles multiple protocol versions and adds caching to improve speed, which is critical for developers building responsive AI agents.

• Released version 4.0.5 with support for the new MCP protocol.
• Added a new Response Caching feature (SEP-2549) to improve performance by allowing clients to reuse server responses.
• Introduced "Client Groups" and updated operations and authentication for clients.
• Added experimental capabilities support to the server initialization process.
• Redesigned the documentation structure with a new sidebar navigation and a dedicated "What's New" section.
• Deprecated the SSE (Server-Sent Events) legacy web transport in favor of HTTP and STDIO.

The framework has been overhauled to support the latest Model Context Protocol (MCP) standards. This update introduces significant new features like response caching and client groups, signaling a shift toward more complex, production-ready AI agent architectures.

• Released FastMCP version 4.0.5 with support for the latest protocol.

• Added a new FastMCP server class that acts as a central container for tools, resources, and prompts.

• Introduced response caching (SEP-2549) to allow clients to reuse data for a set time.

• Added tag-based filtering to selectively show or hide tools based on user types or environments.

• Added support for custom HTTP routes (like health checks) directly within the MCP server.

• Updated the documentation structure to focus on three pillars: Servers, Clients, and Apps.

• Added a "Client Groups" feature and updated authentication and operations for clients.

• Added support for the "modern" MCP protocol era (version 2026-07-28) alongside legacy handshakes.

• Introduced a new response caching system for tools, resources, and prompts to reduce network latency.

• Added "Client Extensions" (SEP-2133) to support vendor-specific capabilities outside the core protocol.

• Detailed three distinct transport mechanisms: In-memory, STDIO (subprocess), and HTTP.

• Added specific guides for testing servers using a Client(server) instance.

• Introduced "Client Groups" for managing tools across multiple independent servers.

• Removed high-level marketing content about Prefect Horizon and general framework philosophy.

The framework has moved to a new version of the Model Context Protocol. This update introduces more granular control over how AI agents interact with tools, including new caching and filtering features that improve performance and security.

FastMCP has moved from a simple framework overview to a technical deep dive. The update introduces support for the "modern" MCP protocol era, client-side response caching, and advanced extension capabilities, signaling a shift toward production-grade performance and enterprise features.