What problem does it solve? React Router behaves differently depending on which mode an app uses, and applying Framework Mode patterns to a Declarative app (or vice versa) produces broken routing, loaders, and data flows. This Skill identifies the installed mode first, then loads the correct mode-specific guidance and version-matched documentation. ## Core Features & Use Cases - Mode Detection: Recognizes Framework, Data, Declarative, and unstable RSC modes from dependencies, config files, route conventions, and imports. - Mode-Specific References: Loads dedicated guidance for routing, loaders, actions, forms, fetchers, pending UI, SSR, pre-rendering, middleware, and type safety per mode. - Version-Matched Docs: Reads the markdown docs shipped inside node_modules/react-router/docs so advice matches the installed package version. - Use Case: When asked to add data loading to an app using createBrowserRouter, the Skill detects Data Mode and applies route-object loader/action patterns instead of Framework route-module conventions. ## Quick Start Ask the assistant to add a loader and form action to your React Router route, and it will detect your app's mode and apply the correct patterns.