Semantics contract for Adaptive Card elements — how labels, headings, live regions, and decorative-vs-meaningful images are exposed to screen readers, and how to test them with `tester.ensureSemantics()`. Use when adding or changing any element, input, or action widget, and at code review.
Optional flutter_adaptive_cards_host_fs package — backend invoke serialization, PlainJson/Teams adapters, AdaptiveCardBackendHandlers, and response effects. Use when wiring Submit/Execute/Refresh/onChange to a flow-service or reviewing associatedInputs + invoke round-trips.
Use when finalizing a change in the Flutter-AdaptiveCards monorepo — before you propose, commit, or merge — as the manual or AI-assisted review gate. Checks monorepo hygiene, Adaptive Cards spec compliance, theming, widget keys, accessibility, and testing.
FVM rules for the Flutter-AdaptiveCards monorepo. Prefix every `flutter` and `dart` shell command with `fvm`. Use when vendored dart/flutter skills show bare commands, when installing or switching the pinned SDK, or before analyze, test, pub, or build_runner workflows.
Classify, audit, and enforce the Diátaxis documentation framework across the Flutter-AdaptiveCards canonical `docs/` and package READMEs. Keeps each doc in exactly one quadrant (tutorial / how-to / reference / explanation) and flags mixed-mode drift. Use when writing or reviewing a doc under `docs/`, adding a `doc_type:` front-matter tag, auditing the doc set for gaps or violations, or when the user mentions Diátaxis or documentation structure. Advisory only — it proposes splits, it does not silently move or rewrite files.
Use before adding a new Adaptive Card element type — implementing its widget, registering it, or testing it. Covers the StatefulWidget + mixin pattern, CardTypeRegistry registration, the extension API, and optional packages (charts).
Use when writing or reviewing model (de)serialization or theming in this repo, or before adding a `fromJson`/`toJson`. The library packages diverge from two things generic Flutter skills assume: they hand-write serialization (no `json_serializable` / code-gen) and style elements from HostConfig (not app-level `ThemeData`/`GoogleFonts`). Read this when a generic skill or habit points you at `@JsonSerializable`, `build_runner` for models, or `ColorScheme` app theming inside `packages/`.
Use before modifying styling, colors, spacing, fonts, or HostConfig parsing in any element. Explains how Adaptive Cards HostConfig maps to Flutter rendering, how ReferenceResolver bridges the two, and how light/dark themes are structured.