adaptive-cards-backend-host

name	adaptive-cards-backend-host
description	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.

Backend Host Integration Skill

Optional package: packages/flutter_adaptive_cards_host_fs

• Depends on: flutter_adaptive_cards_fs, http
• Published: Yes — pub.dev (barrel: lib/flutter_adaptive_cards_host_fs.dart)
• Docs: docs/backend-host-integration.md
• Design history: docs/archive/specs/2026-06-07-backend-host-integration-design.md

When to use

Scenario	Package
Render cards; hand-wire InheritedAdaptiveCardHandlers	Core only
Teams-correct invoke payloads (associatedInputs)	Core (always)
Serialize → POST → parse → applyTo automatically	flutter_adaptive_cards_host_fs

Key types

• AdaptiveCardBackendHandlers — wraps card subtree; wires onSubmit, onExecute, onRefresh, onChange
• AdaptiveCardBackendClient / HttpAdaptiveCardBackendClient — transport
• PlainJsonInvokeAdapter / TeamsInvokeAdapter — request/response JSON shapes
• AdaptiveCardInvokeResponse.applyTo — applyPatches, setInputErrors, replaceCard (via onCardReplaced)

Requires shared GlobalKey<RawAdaptiveCardState> on handlers and RawAdaptiveCard (except onChange, which uses invoke.cardState).

Tests

No golden tests. Run from package directory:

cd packages/flutter_adaptive_cards_host_fs
fvm flutter test

Primary files:

• test/handlers/backend_handlers_test.dart
• test/adapters/plain_json_invoke_adapter_test.dart
• test/adapters/teams_invoke_adapter_test.dart
• test/client/http_backend_client_test.dart

Core associatedInputs tests remain in packages/flutter_adaptive_cards_fs/test/utils/associated_inputs_test.dart and related input tests.

Related skills

• adaptive-cards-monorepo-workspace — workspace layout and fvm working directories
• adaptive-cards-testing — core widget/notifier test patterns
• adaptive-cards-release-engineer — sync version: and flutter_adaptive_cards_fs: ^<version> on post-release bump