FastMCP 3.0 is Here | Prefab

FastMCP 3.0 just dropped with a complete backend rewrite that makes everything work better together. Jeremiah and Adam walk through the new tool-based permissions, progressive disclosure, and the new providers/transformers architecture that lets you store tools anywhere - databases, file systems, other MCP servers. Plus we're already talking about what's coming in 3.1 with Prefab, where you can write Python code and get actual React UIs without touching frontend code. Return a chart object, get a chart. Return data, get an interactive table. Breaking changes are minimal - mostly just sync-to-async conversions covered in our upgrade guide. CONTENT: 0:00 FastMCP 3.0 release announcement 0:25 Backend rewrite and new features overview 0:38 Tool-based RBAC and progressive disclosure 2:19 Providers and transformers architecture discussion 2:38 How providers and transformers work 4:19 Breaking changes and migration guide 7:25 Prefab introduction and MCP apps context 8:41 Prefab detailed explanation begins 10:16 Prefab technical details (JSON DSL and Python) 11:54 Prefab agent capabilities 13:10 Wrap up and where to find more info Links: FastMCP: gofastmcp.com Horizon: horizon.prefect.io Prefab: prefab.prefect.io Webinar Link in comments!