FastMCP 2.13.0: Cache Me If You Can
FastMCP 2.13 “Cache Me If You Can” represents a fundamental maturation of the framework. After months of community feedback on authentication and state management, this release delivers the infrastructure FastMCP needs to handle production workloads: persistent storage, response caching, and pragmatic OAuth improvements that reflect real-world deployment challenges.💾 Pluggable storage backends bring persistent state to FastMCP servers. Built on py-key-value-aio, a new library from FastMCP maintainer Bill Easton (@strawgate), the storage layer provides encrypted disk storage by default, platform-aware token management, and a simple key-value interface for application state. We’re excited to bring this elegantly designed library into the FastMCP ecosystem - it’s both powerful and remarkably easy to use, including wrappers to add encryption, TTLs, caching, and more to backends ranging from Elasticsearch, Redis, DynamoDB, filesystem, in-memory, and more!🔐 OAuth maturity brings months of production learnings into the framework. The new consent screen prevents confused deputy and authorization bypass attacks discovered in earlier versions, while the OAuth proxy now issues its own tokens with automatic key derivation. RFC 7662 token introspection support enables enterprise auth flows, and path prefix mounting enables OAuth-protected servers to integrate into existing web applications. FastMCP now supports out-of-the-box authentication with WorkOS and AuthKit, GitHub, Google, Azure (Entra ID), AWS Cognito, Auth0, Descope, Scalekit, JWTs, and RFC 7662 token introspection.⚡ Response Caching Middleware dramatically improves performance for expensive operations, while Server lifespans provide proper initialization and cleanup hooks that run once per server instance instead of per client session.✨ Developer experience improvements include Pydantic input validation, icon support, RFC 6570 query parameters for resource templates, improved Context API methods, and async file/directory resources.
FastMCP 2.8: Transform and Roll Out
FastMCP 2.8 is here, and it’s all about taking control of your tools.This release is packed with new features for curating the perfect LLM experience:🛠️ Tool TransformationThe headline feature lets you wrap any tool—from your own code, a third-party library, or an OpenAPI spec—to create an enhanced, LLM-friendly version. You can rename arguments, rewrite descriptions, and hide parameters without touching the original code.This feature was developed in close partnership with Bill Easton. As Bill brilliantly put it, “Tool transformation flips Prompt Engineering on its head: stop writing tool-friendly LLM prompts and start providing LLM-friendly tools.”🏷️ Component ControlNow that you’re transforming tools, you need a way to hide the old ones! In FastMCP 2.8 you can programmatically enable/disable any component, and for everyone who’s been asking what FastMCP’s tags are for—they finally have a purpose! You can now use tags to declaratively filter which components are exposed to your clients.🚀 Pragmatic by DefaultLastly, to ensure maximum compatibility with the ecosystem, we’ve made the pragmatic decision to default all OpenAPI routes to Tools, making your entire API immediately accessible to any tool-using agent. When the industry catches up and supports resources, we’ll restore the old default — but no reason you should do extra work before OpenAI, Anthropic, or Google!
