Add LocalChatClientWithAgents sample (Apple Intelligence + Agent Framework)

[mattleibow]

Summary

Adds a new AI sample under 10.0/AI/LocalChatClientWithAgents/ — a .NET MAUI Travel Planner app powered entirely by on-device Apple Intelligence. No cloud API keys or endpoints required.

Landmarks	Trip Planning	Itinerary	Chat

What it demonstrates

• Microsoft.Extensions.AI (IChatClient) backed by Apple Intelligence on iOS/macCatalyst
• Microsoft Agent Framework (Microsoft.Agents.AI) with a 4-agent pipeline:
  • Travel Planner → Researcher (RAG) → Itinerary Planner (tools + streaming) → Translator (conditional)
• On-device RAG using NLEmbeddingGenerator for semantic landmark and continent search
• Streaming JSON deserialization for progressive UI updates
• Tool calling with agents to discover points of interest
• Conditional routing (translation skipped for English)
• Chat assistant with floating overlay, tool calling, and embedding-based search

App flow

1. Landmarks page — Browse 21 world landmarks across 7 continents with semantic search
2. Trip planning page — Select duration (1-7 days) and language for a selected landmark
3. Itinerary page — Stream a multi-day itinerary with weather forecasts and map views
4. Chat assistant — Floating chat overlay with tool calling (landmark search, continent listing, trip planning)

Architecture

User Input → [Travel Planner] → [Researcher] → [Itinerary Planner] → [Translator?] → Output

Agent	Purpose	Key Feature
Travel Planner	Extracts destination, duration, and language	NLP intent parsing
Researcher	Matches destination against local landmark database	RAG with NL embeddings
Itinerary Planner	Generates multi-day itinerary with real places	Tool calling + streaming JSON
Translator	Translates itinerary if non-English language requested	Conditional routing

Platform support

• ✅ iOS 26+ / macCatalyst 26+ (Apple Intelligence)
• ❌ Android / Windows (PlatformNotSupportedException at startup)

Key packages

• Microsoft.Maui.Essentials.AI (dotnet10 preview feed)
• Microsoft.Agents.AI / Microsoft.Agents.AI.Hosting / Microsoft.Agents.AI.Workflows
• Microsoft.Extensions.AI 10.3.0
• CommunityToolkit.Mvvm 8.4.0

Structure

Follows the same folder structure as the existing 10.0/AI/ChatClient and 10.0/AI/ChatClientWithTools samples with README (frontmatter, screenshots, key files, sample prompts), images directory, and NuGet.config.

[Copilot]

Pull request overview

Adds a new .NET MAUI AI sample (10.0/AI/LocalChatClientWithAgents/) demonstrating an on-device Apple Intelligence travel planner that combines Microsoft.Extensions.AI (IChatClient) with a multi-agent Microsoft Agent Framework workflow (RAG + streaming itinerary + conditional translation), plus a chat overlay with tool calling.

Changes:

• Introduces a 4-agent itinerary workflow (Travel Planner → Researcher/RAG → Itinerary Planner/tools+streaming → Translator/conditional) and associated streaming/merge utilities.
• Adds new MAUI pages/views/viewmodels for landmark browsing, trip planning, streaming itinerary rendering, and a chat overlay UI with markdown rendering.
• Adds sample resources (styles, icons, splash, embedded JSON datasets) and platform scaffolding (iOS/macCatalyst/Android/Windows).

Reviewed changes

Copilot reviewed 93 out of 141 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkListItemView.xaml.cs	Landmark list item control code-behind + tap event plumbing
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkListItemView.xaml	Landmark list item UI layout (thumbnail + title)
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkHorizontalListView.xaml.cs	Horizontal list wrapper control code-behind + event forwarding
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkHorizontalListView.xaml	Horizontal scroll + BindableLayout templating for landmarks
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkFeaturedItemView.xaml.cs	Featured landmark control code-behind + tap event plumbing
10.0/AI/LocalChatClientWithAgents/src/Views/Landmarks/LandmarkFeaturedItemView.xaml	Featured landmark UI (background image + title overlay)
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/MessageView.xaml.cs	Simple wrapper view code-behind for itinerary status/error display
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/MessageView.xaml	Status/error overlay UI for itinerary page
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/LandmarkDetailMapView.xaml.cs	Map view code-behind (pins + region positioning)
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/LandmarkDetailMapView.xaml	Map view XAML with pin template
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/LandmarkDescriptionView.xaml.cs	Simple wrapper view code-behind for landmark details section
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/LandmarkDescriptionView.xaml	Landmark title/tags/description UI
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ItineraryView.xaml.cs	Simple wrapper view code-behind for itinerary content section
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ItineraryView.xaml	Itinerary header/rationale/day list UI
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ItineraryPlanningView.xaml.cs	Simple wrapper view code-behind for planning progress section
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ItineraryPlanningView.xaml	“planning” progress UI with fading status trail
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/DayView.xaml.cs	Simple wrapper view code-behind for a single day card
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/DayView.xaml	Day card UI (map + weather/title/subtitle + activities)
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ActivityListView.xaml.cs	Simple wrapper view code-behind for day activities list
10.0/AI/LocalChatClientWithAgents/src/Views/Itinerary/ActivityListView.xaml	Activities list UI (bullet + title/description)
10.0/AI/LocalChatClientWithAgents/src/Views/Chat/MarkdownConverter.cs	Markdig-based markdown → FormattedString converter for chat bubbles
10.0/AI/LocalChatClientWithAgents/src/Views/Chat/ChatOverlayView.xaml.cs	Chat overlay behavior (sizing, show/hide animation, autoscroll)
10.0/AI/LocalChatClientWithAgents/src/Views/Chat/ChatOverlayView.xaml	Chat overlay UI templates (user/assistant/tool call/result)
10.0/AI/LocalChatClientWithAgents/src/Views/Chat/ChatBubbleTemplateSelector.cs	Template selection based on bubble type
10.0/AI/LocalChatClientWithAgents/src/ViewModels/TripPlanningViewModel.cs	Trip configuration VM (day count, language, tag generation)
10.0/AI/LocalChatClientWithAgents/src/ViewModels/LandmarksViewModel.cs	Landmarks browsing VM + embedding progress UI state
10.0/AI/LocalChatClientWithAgents/src/ViewModels/ItineraryViewModel.cs	Itinerary VM wrapper + day VM creation
10.0/AI/LocalChatClientWithAgents/src/ViewModels/ItineraryPageViewModel.cs	Orchestrates streaming itinerary generation + weather enrichment
10.0/AI/LocalChatClientWithAgents/src/ViewModels/DayPlanViewModel.cs	Day plan VM (activities, weather)
10.0/AI/LocalChatClientWithAgents/src/ViewModels/ChatViewModel.cs	Chat UI VM (streaming updates, tool call/result bubbles)
10.0/AI/LocalChatClientWithAgents/src/ViewModels/ChatBubbleViewModel.cs	Bubble VM + expand/collapse for tool details
10.0/AI/LocalChatClientWithAgents/src/Services/WeatherService.cs	Open-Meteo integration for daily forecasts
10.0/AI/LocalChatClientWithAgents/src/Services/TaggingService.cs	Tag extraction via IChatClient structured output
10.0/AI/LocalChatClientWithAgents/src/Services/StreamingJsonDeserializer.cs	Streaming JSON reconstruction + incremental deserialization helper
10.0/AI/LocalChatClientWithAgents/src/Services/JsonMerger.cs	Deep-merge utility for progressively overlaying translated JSON
10.0/AI/LocalChatClientWithAgents/src/Services/ItineraryService.cs	Streams workflow output, incremental parsing, translation merge handling
10.0/AI/LocalChatClientWithAgents/src/Services/DataService.cs	Loads datasets + generates embeddings + semantic search
10.0/AI/LocalChatClientWithAgents/src/Services/ChatService.cs	Tool-enabled chat service + navigation tool callback
10.0/AI/LocalChatClientWithAgents/src/Services/BufferedChatClient.cs	Delegating chat client that buffers streaming text updates
10.0/AI/LocalChatClientWithAgents/src/Resources/Styles/Styles.xaml	App-wide control styles
10.0/AI/LocalChatClientWithAgents/src/Resources/Styles/Colors.xaml	App-wide color palette + brushes
10.0/AI/LocalChatClientWithAgents/src/Resources/Splash/splash.svg	Splash SVG asset
10.0/AI/LocalChatClientWithAgents/src/Resources/Raw/pointsOfInterestData.json	Embedded points-of-interest dataset for the sample
10.0/AI/LocalChatClientWithAgents/src/Resources/Raw/landmarkData.json	Embedded landmarks dataset for the sample
10.0/AI/LocalChatClientWithAgents/src/Resources/Raw/AboutAssets.txt	MAUI template raw-assets guidance file
10.0/AI/LocalChatClientWithAgents/src/Resources/AppIcon/appiconfg.svg	App icon foreground SVG
10.0/AI/LocalChatClientWithAgents/src/Resources/AppIcon/appicon.svg	App icon background SVG
10.0/AI/LocalChatClientWithAgents/src/Properties/launchSettings.json	Debug launch profile settings
10.0/AI/LocalChatClientWithAgents/src/Platforms/iOS/Resources/PrivacyInfo.xcprivacy	iOS privacy manifest
10.0/AI/LocalChatClientWithAgents/src/Platforms/iOS/Program.cs	iOS app entry point
10.0/AI/LocalChatClientWithAgents/src/Platforms/iOS/Info.plist	iOS app metadata
10.0/AI/LocalChatClientWithAgents/src/Platforms/iOS/AppDelegate.cs	iOS app delegate
10.0/AI/LocalChatClientWithAgents/src/Platforms/Windows/app.manifest	Windows manifest (template)
10.0/AI/LocalChatClientWithAgents/src/Platforms/Windows/Package.appxmanifest	Windows packaging manifest (template)
10.0/AI/LocalChatClientWithAgents/src/Platforms/Windows/App.xaml.cs	Windows app bootstrap
10.0/AI/LocalChatClientWithAgents/src/Platforms/Windows/App.xaml	Windows XAML app definition
10.0/AI/LocalChatClientWithAgents/src/Platforms/MacCatalyst/Program.cs	MacCatalyst app entry point
10.0/AI/LocalChatClientWithAgents/src/Platforms/MacCatalyst/Info.plist	MacCatalyst app metadata
10.0/AI/LocalChatClientWithAgents/src/Platforms/MacCatalyst/Entitlements.plist	MacCatalyst entitlements (network client + sandbox)
10.0/AI/LocalChatClientWithAgents/src/Platforms/MacCatalyst/AppDelegate.cs	MacCatalyst app delegate
10.0/AI/LocalChatClientWithAgents/src/Platforms/Android/Resources/values/colors.xml	Android color resources
10.0/AI/LocalChatClientWithAgents/src/Platforms/Android/MainApplication.cs	Android application bootstrap
10.0/AI/LocalChatClientWithAgents/src/Platforms/Android/MainActivity.cs	Android main activity
10.0/AI/LocalChatClientWithAgents/src/Platforms/Android/AndroidManifest.xml	Android manifest + network permissions
10.0/AI/LocalChatClientWithAgents/src/Pages/TripPlanningPage.xaml.cs	Trip planning page navigation + lifecycle cancellation
10.0/AI/LocalChatClientWithAgents/src/Pages/TripPlanningPage.xaml	Trip planning UI (duration/language picker + generate CTA)
10.0/AI/LocalChatClientWithAgents/src/Pages/LandmarksPage.xaml.cs	Landmarks page interactions + chat overlay wiring
10.0/AI/LocalChatClientWithAgents/src/Pages/LandmarksPage.xaml	Landmarks browsing UI + embedding-generation blocker overlay
10.0/AI/LocalChatClientWithAgents/src/Pages/ItineraryPage.xaml.cs	Itinerary page lifecycle (generate/cancel) + back navigation
10.0/AI/LocalChatClientWithAgents/src/Pages/ItineraryPage.xaml	Itinerary UI switching (planning/results/error)
10.0/AI/LocalChatClientWithAgents/src/NuGet.config	Adds dotnet10 preview feed for Apple Intelligence package
10.0/AI/LocalChatClientWithAgents/src/Models/Weather.cs	Weather forecast DTOs + weather code mapping helpers
10.0/AI/LocalChatClientWithAgents/src/Models/PointOfInterest.cs	POI model + embeddings field
10.0/AI/LocalChatClientWithAgents/src/Models/Landmark.cs	Landmark model + computed image names + location + embeddings field
10.0/AI/LocalChatClientWithAgents/src/Models/Itinerary.cs	Itinerary schema + validation metadata + example generator
10.0/AI/LocalChatClientWithAgents/src/MauiProgram.cs	DI registration + Apple Intelligence gating + workflow registration
10.0/AI/LocalChatClientWithAgents/src/MauiAppBuilderExtensions.cs	Apple Intelligence + embeddings DI helpers
10.0/AI/LocalChatClientWithAgents/src/LocalChatClientWithAgents.slnx	Solution entry for the new sample
10.0/AI/LocalChatClientWithAgents/src/LocalChatClientWithAgents.csproj	Project definition + NuGet package references + assets
10.0/AI/LocalChatClientWithAgents/src/Converters/IsNotNullOrEmptyConverter.cs	Converter used for conditional UI visibility
10.0/AI/LocalChatClientWithAgents/src/Converters/IsNotNullConverter.cs	Converter used for null checks in XAML
10.0/AI/LocalChatClientWithAgents/src/Converters/InvertedBoolConverter.cs	Converter used for boolean inversion in XAML
10.0/AI/LocalChatClientWithAgents/src/AppShell.xaml.cs	Shell route registration
10.0/AI/LocalChatClientWithAgents/src/AppShell.xaml	Shell structure (LandmarksPage as root)
10.0/AI/LocalChatClientWithAgents/src/App.xaml.cs	Application bootstrap
10.0/AI/LocalChatClientWithAgents/src/App.xaml	Resource dictionaries + converters registration
10.0/AI/LocalChatClientWithAgents/src/AI/WorkflowModels.cs	Workflow model types exchanged between executors/agents
10.0/AI/LocalChatClientWithAgents/src/AI/WorkflowEvents.cs	Custom workflow events for status + streaming text chunks
10.0/AI/LocalChatClientWithAgents/src/AI/ItineraryWorkflowTools.cs	RAG provider + POI tool exposed to itinerary agent
10.0/AI/LocalChatClientWithAgents/src/AI/ItineraryWorkflowExtensions.cs	Agent registrations + workflow graph + conditional translation routing
10.0/AI/LocalChatClientWithAgents/src/AI/5_OutputExecutor.cs	Workflow output executor (final status event)
10.0/AI/LocalChatClientWithAgents/src/AI/4_TranslatorExecutor.cs	Translator executor streaming translated JSON as workflow events
10.0/AI/LocalChatClientWithAgents/src/AI/3_ItineraryPlannerExecutor.cs	Itinerary planner executor streaming itinerary JSON as workflow events
10.0/AI/LocalChatClientWithAgents/src/AI/2_ResearcherExecutor.cs	Researcher executor using RAG context to pick best destination
10.0/AI/LocalChatClientWithAgents/src/AI/1_TravelPlannerExecutor.cs	Travel planner executor extracting intent into a typed message
10.0/AI/LocalChatClientWithAgents/README.md	Sample documentation (architecture, prerequisites, run instructions)

[PureWeen]

�� Multi-Model Code Review -- PR #744 (LocalChatClientWithAgents)

CI Status: ✅ All checks passing

Consensus Findings (flagged by 2+ of 5 models)

🟡 MODERATE -- Race condition: embeddings never awaited (5/5 consensus)

File: src/Services/DataService.cs:44,114

ContinueWith schedules the _embeddingsTask assignment asynchronously after _initializationTask completes, on a thread pool thread. WaitUntilReadyAsync() awaits _initializationTask, then immediately checks if (_embeddingsTask is not null) -- but the ContinueWith callback may not have run yet, so _embeddingsTask is still null. The method returns with embeddings not yet started.

Fix:

// Replace ContinueWith with direct chaining:
_embeddingsTask = _initializationTask.ContinueWith(_ => Task.Run(GenerateEmbeddingsAsync)).Unwrap();

🟡 MODERATE -- Cancel() leaves disposed CTS; ObjectDisposedException on iOS swipe-abort (5/5 consensus)

File: src/ViewModels/ItineraryPageViewModel.cs:113-117

Cancel() disposes _cancellationTokenSource without replacing it. On iOS, a swipe-back gesture fires NavigatingFrom (which calls Cancel()) but can be aborted -- the page stays alive with a disposed CTS. Any subsequent GenerateAsync() call hits _cancellationTokenSource.Cancel() on the disposed instance and throws ObjectDisposedException.

Fix:

public void Cancel()
{
    _cancellationTokenSource.Cancel();
    _cancellationTokenSource.Dispose();
    _cancellationTokenSource = new CancellationTokenSource();
}

🟡 MODERATE -- JsonDocument never disposed; memory leak per streaming session (5/5 consensus)

Files: src/Services/JsonMerger.cs:22 + src/Services/ItineraryService.cs:79

JsonMerger holds _baseDocument (a JsonDocument which rents pooled/native memory) but never implements IDisposable. In ItineraryService.StreamItineraryAsync, old merger instances are silently overwritten on executor switch without disposal. Per streaming session, at least one JsonDocument's pooled memory leaks.

Fix: JsonMerger must implement IDisposable and dispose _baseDocument; ItineraryService must use using at call sites.

🟡 MODERATE -- SearchLandmarksAsync skips embedding wait; silent semantic-search degradation (5/5 consensus)

File: src/Services/DataService.cs:118

Both SearchLandmarksAsync and SearchPointsOfInterestAsync only await _initializationTask (data load), never _embeddingsTask. If called before embedding generation completes, every item's Embeddings is null, scores -1f, and results are ranked by keyword substring boost only. Semantic search silently falls back to substring matching.

🟢 MINOR -- Single embedding failure stops all remaining items (2/5 consensus)

File: src/Services/DataService.cs:178

The entire embedding loop is wrapped in a single try/catch. An exception on one item aborts all remaining landmarks and POIs.

🟢 MINOR -- Full ItineraryViewModel rebuild per streaming chunk (2/5 consensus)

File: src/ViewModels/ItineraryPageViewModel.cs:82

A new ItineraryViewModel is allocated on every streamed JSON chunk, forcing full UI rebind and causing visible flicker.

---

Recommended Action: ⚠️ Request Changes

1. Fix ContinueWith race with .Unwrap() chaining in DataService
2. Replace disposed CTS in Cancel()
3. Make JsonMerger implement IDisposable and use using at call sites
4. Await embedding readiness in SearchLandmarksAsync / SearchPointsOfInterestAsync

Review generated by multi-model consensus (Claude Opus, Claude Sonnet, Gemini Pro, GPT-Codex)