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Skill

maui-ai-debugging

debug .NET MAUI application issues

Covers MAUI .NET Mobile Debugging

Description

Legacy DevFlow debug skill. USE FOR: `maui-ai-debugging`, `maui devflow`, screenshots, visual tree, Blazor CDP, simulator/emulator debugging. DO NOT USE FOR: setup, desktop automation, AppleScript, host `xdotool`.

SKILL.md

MAUI AI Debugging

Compatibility note: this legacy skill name is retained for older clients. The canonical replacement is maui-devflow-debug, installed through maui devflow init / maui devflow skills update.

Build, deploy, inspect, and debug .NET MAUI apps from the terminal. This skill enables a complete feedback loop: build → deploy → inspect → fix → rebuild.

Prerequisites

dotnet tool install --global Microsoft.Maui.Cli --prerelease || dotnet tool update --global Microsoft.Maui.Cli --prerelease
dotnet tool install --global androidsdk.tool    # Android only
dotnet tool install --global appledev.tools     # iOS/Mac only

Keep DevFlow skills up to date with maui devflow skills update. The hidden maui devflow update-skill compatibility command runs the same bundled updater and may remove this legacy skill after installing current replacements.

Optional Session Feedback Nudge

If this legacy workflow involved repeated DevFlow retries, unclear workarounds, or a long debugging session, ask whether the user wants to run maui-devflow-session-review to summarize friction for MAUI DevFlow product feedback. Do not run it automatically.

Integrating MauiDevFlow into a MAUI App

For complete setup instructions, see references/setup.md.

Quick summary:

  1. Add NuGet packages (Microsoft.Maui.DevFlow.Agent, and Microsoft.Maui.DevFlow.Blazor for Blazor Hybrid)
    • For Linux/GTK apps (detected via grep -i 'GirCore\|Maui\.Gtk' *.csproj), use Agent.Gtk and Blazor.Gtk instead
    • For macOS (AppKit) apps (detected via grep -i 'Platform\.Maui\.MacOS' *.csproj), the standard Agent and Blazor packages include macOS support
  2. Register in MauiProgram.cs inside #if DEBUG
  3. For Blazor Hybrid: chobitsu.js is auto-injected (no manual script tag needed)
  4. For Mac Catalyst: ensure network.server entitlement
  5. For Android: run adb reverse for broker + agent ports
  6. For Linux: no special network setup needed (direct localhost)
  7. For macOS (AppKit): separate app head project, uses open App.app to launch. See references/macos.md

Core Workflow

0. Verify DevFlow Availability

Before building or launching anything, determine if DevFlow is available for the current project.

Check integration (project files — the source of truth):

# Check if any csproj in the project has DevFlow packages
grep -rl "MauiDevFlow\|Maui\.DevFlow" --include="*.csproj" .

If grep returns results, DevFlow IS integrated — even if maui devflow list shows nothing.

Check runtime connection:

maui devflow list                          # shows connected agents
maui devflow broker status                 # shows broker health
maui devflow diagnose                      # full end-to-end health check (recommended)

Decision tree — what to do based on results:

Project has DevFlow packages?Agent in list?Action
✅ Yes✅ YesReady — proceed to inspection/interaction
✅ Yes❌ NoApp not running in Debug, or broker issue. Launch app, then maui devflow wait
❌ NoNeed to integrate DevFlow (see "Integrating MauiDevFlow into a MAUI App")

⚠️ CRITICAL: maui devflow list shows RUNTIME state (connected agents), NOT project integration. An empty list does NOT mean "DevFlow is not installed." Always check project files first.

After launching the app (via dotnet build -t:Run or through Aspire):

maui devflow wait                          # blocks until agent connects (default 120s)
maui devflow wait --project path/to/App.csproj  # filter to specific project

ALWAYS run wait after launching. Never assume the agent is connected — verify it.

1. Ensure a Device/Simulator/Emulator is Running

⚠️ Multi-project conflict avoidance: When multiple projects may run simultaneously (common with AI agents), each project should use its own dedicated simulator/emulator to prevent apps from replacing each other. Check what's already in use first:

maui devflow list     # check if any agents are already connected (runtime state only — see Step 0 for integration check)

If another iOS or Android agent is already registered, create a new simulator/emulator for your project instead of reusing the one that's already booted.

iOS Simulator:

xcrun simctl list devices booted                              # check booted sims

# Create a project-dedicated simulator to avoid conflicts
xcrun simctl create "MyApp-iPhone17Pro" "iPhone 17 Pro" "iOS 26.2"
xcrun simctl boot <UDID>                                      # boot the new sim

Android Emulator:

android avd list                                              # list AVDs

# Create a project-dedicated emulator to avoid conflicts
android avd create --name "MyApp-Pixel8" \
  --sdk "system-images;android-35;google_apis;arm64-v8a" --device pixel_8
android avd start --name "MyApp-Pixel8"

Mac Catalyst / macOS (AppKit) / Linux/GTK: No device setup needed — runs as desktop app. Multiple desktop apps can run simultaneously without conflicts.

2. Detect the TFM

IMPORTANT: Before building, detect the correct Target Framework Moniker from the project. Do NOT assume net10.0 — many projects use net9.0, net8.0, etc.

grep -i 'TargetFrameworks' *.csproj Directory.Build.props 2>/dev/null

Use the detected version (e.g. net9.0) in all build commands. The examples use $TFM.

3. Build, Deploy, and Connect

Follow these steps for every launch and rebuild.

Step 1: Kill any previous instance (skip on first launch). A stale app's agent stays registered with the broker, causing maui devflow wait to return the old port instantly instead of waiting for the new build.

# Stop the async shell from the previous launch, then confirm:
maui devflow list                 # should show no agents (or only unrelated ones)

Step 2: Launch in an async shell.

# iOS Simulator
dotnet build -f $TFM-ios -t:Run -p:_DeviceName=:v2:udid=<UDID>

# Android Emulator
dotnet build -f $TFM-android -t:Run

# Mac Catalyst
dotnet build -f $TFM-maccatalyst -t:Run

# macOS AppKit — build exits after compiling; launch separately
dotnet build -f $TFM-macos <path-to-macos-project>
open path/to/bin/Debug/$TFM-macos/osx-arm64/AppName.app

# Linux/GTK
dotnet run --project <path-to-gtk-project>

⚠️ Process lifecycle rules:

  • dotnet build -t:Run (iOS, Android, Mac Catalyst) and dotnet run (Linux/GTK) block for the lifetime of the app. Killing or stopping the shell kills the app. Use mode: "async" with initial_wait: 120 and do NOT stop the shell until you are done.
  • macOS (AppKit) is the exception: dotnet build exits after compiling, and open launches the app independently — the app survives shell termination.

Step 3: Wait for the agent — never use sleep.

maui devflow wait                                # blocks until agent registers (default 120s)
maui devflow wait --project path/to/App.csproj   # filter to specific project

maui devflow wait prints the assigned port as soon as the agent connects. Exit code 1 means timeout. If wait times out, run maui devflow diagnose to identify the issue. Check async shell output for build errors.

Android only — set up port forwarding after the agent connects:

adb reverse tcp:19223 tcp:19223   # Broker (lets agent in emulator reach host broker)
adb forward tcp:<port> tcp:<port> # Agent (lets CLI reach agent in emulator)

To rebuild: repeat from Step 1. See references/troubleshooting.md if the build fails.

4. Inspect and Interact

Typical inspection flow:

  1. maui devflow ui tree --depth 15 --fields "id,type,text,automationId" — tree with key fields only (depth 15 reaches most controls)
  2. maui devflow ui tree --window 1 — filter to a specific window (0-based index)
  3. maui devflow ui query --automationId "MyButton" — find specific elements
  4. maui devflow ui query --type Entry --fields "id,text,automationId" — all Entry fields with specific fields
  5. maui devflow ui element <id> — get full details (type, bounds, visibility, children)
  6. maui devflow ui property <id> Text — read any property by name
  7. maui devflow ui screenshot --output screen.png — visual verification (auto-scaled to 1x on HiDPI)
  8. maui devflow ui screenshot --id <elementId> --output el.png — element-only screenshot
  9. maui devflow ui screenshot --selector "Button" --output btn.png — screenshot by CSS selector

Property inspection is more reliable than screenshots for verifying exact runtime values:

maui devflow ui property <id> BackgroundColor    # verify dark mode colors
maui devflow ui property <id> IsVisible          # check element visibility

Live editing (no rebuild needed):

maui devflow ui set-property <id> TextColor "Tomato"
maui devflow ui set-property <id> FontSize "24"

Supports: string, bool, int, double, Color (named/hex), Thickness, enums. Changes persist until the app restarts — safe for experimentation.

Typical interaction flow:

  1. maui devflow ui fill --automationId "MyEntry" "text" — type into Entry/Editor fields (no query needed)
  2. maui devflow ui tap --automationId "MyButton" — tap buttons, checkboxes, list items
  3. maui devflow ui clear --automationId "MyEntry" — clear text fields
  4. Or use element IDs from tree/query: maui devflow ui tap <elementId>
  5. Take screenshot to verify result, or use --and-screenshot on the action

Blazor WebView (if applicable):

  1. maui devflow webview snapshot — DOM tree as accessible text (best for AI)
  2. maui devflow webview Input fill "css-selector" "text" — fill inputs
  3. maui devflow webview Input dispatchClickEvent "css-selector" — click elements
  4. maui devflow webview Runtime evaluate "js-expression" — run JS

Multiple BlazorWebViews: If the app has more than one BlazorWebView, each is registered independently with its AutomationId. Use webview webviews to list them, then target a specific one with --webview (or -w):

maui devflow webview webviews                                  # list all WebViews
maui devflow webview -w BlazorLeft snapshot                    # snapshot of a specific WebView
maui devflow webview -w 1 Runtime evaluate "document.title"    # target by index

Without --webview, commands target the first (index 0) WebView.

Live CSS/DOM editing in Blazor (no rebuild needed):

maui devflow webview Runtime evaluate "document.querySelector('h1').style.color = 'tomato'"
maui devflow webview Runtime evaluate "document.documentElement.style.setProperty('--bg-color', '#1a1a2e')"

5. Reading Application Logs

MauiDevFlow automatically captures all ILogger output and WebView console.* calls to rotating log files, retrievable remotely:

maui devflow ui logs                   # fetch 100 most recent log entries
maui devflow ui logs --limit 50        # fetch 50 entries
maui devflow ui logs --source webview  # only WebView/Blazor console logs
maui devflow ui logs --source native   # only native ILogger logs
maui devflow ui logs --follow          # stream logs in real-time (Ctrl+C to stop)
maui devflow ui logs -f --source native  # stream only native logs
maui devflow ui logs -f --json         # stream as JSONL (machine-readable)

Debugging workflow: Reproduce the issue → maui devflow ui logs --limit 20 → check for errors. Add temporary ILogger calls for more detail, rebuild, reproduce, and fetch logs again.

6. Screen Recording

Capture video of the app while performing interactions. Recording is host-side (not in-app) using platform-native tools.

# Start recording (default 30s timeout)
maui devflow recording start --output demo.mp4

# Interact with the app
maui devflow ui tap <buttonId>
maui devflow ui navigate "//blazor"
maui devflow ui fill <entryId> "Hello World"

# Stop and save
maui devflow recording stop

Platform tools used automatically by MauiDevFlow's recording backend (implementation detail — do not invoke these directly unless the user explicitly asked for host-level recording):

  • Android: adb screenrecord (max 180s, capped with warning)
  • iOS Simulator: xcrun simctl io recordVideo
  • Mac Catalyst / macOS (AppKit): screencapture -v (targets app window when possible)
  • Windows/Linux: ffmpeg (must be on PATH)

Options: --timeout <seconds> (default 30), --output <path> (default recording_<timestamp>.mp4). Only one recording at a time — stop before starting a new one.

7. Network Request Monitoring

Monitor HTTP requests made by the app in real-time. MauiDevFlow automatically intercepts all IHttpClientFactory-based HTTP traffic via a DelegatingHandler — no app code changes needed beyond the standard AddMauiDevFlowAgent() setup.

# Live monitor — streams requests as they happen (Ctrl+C to stop)
maui devflow network

# JSONL streaming — machine-readable, one JSON object per line
maui devflow network --json

# One-shot: list recent captured requests
maui devflow network list

# Filter by method or host
maui devflow network list --method POST
maui devflow network list --host api.example.com

# Full request/response details (headers + body)
maui devflow network detail <requestId>

# Clear captured requests
maui devflow network clear

How it works:

  • A DelegatingHandler wraps the platform's HTTP handler (AndroidMessageHandler, NSUrlSessionHandler, etc.), capturing request/response metadata, headers, and bodies
  • Auto-injected via ConfigureHttpClientDefaults — works for all IHttpClientFactory clients
  • For new HttpClient() outside DI, use DevFlowHttp.CreateClient() helper
  • Bodies up to 256KB are captured (configurable via AgentOptions.MaxNetworkBodySize)
  • A ring buffer (default 500 entries) stores recent requests in-memory

JSONL output is ideal for AI parsing — pipe to jq or process programmatically:

maui devflow network --json | jq 'select(.statusCode >= 400)'

WebSocket streaming: The live monitor uses WebSocket (/ws/network) for real-time push. Connecting clients receive a replay of buffered history, then live entries as they arrive.

8. App Storage (Preferences & Secure Storage)

Read, write, and delete app preferences and secure storage entries remotely. Useful for debugging state, resetting app configuration, or injecting test values.

# Preferences (typed key-value store)
maui devflow preferences list                       # list all known keys
maui devflow preferences get theme_mode             # get a string value
maui devflow preferences get counter --type int     # get a typed value
maui devflow preferences set api_url "https://dev.example.com"
maui devflow preferences set dark_mode true --type bool
maui devflow preferences delete temp_key
maui devflow preferences clear                      # clear all

# Shared preferences containers
maui devflow preferences list --sharedName settings
maui devflow preferences set key val --sharedName settings

# Secure Storage (encrypted, string values only)
maui devflow secure-storage get auth_token
maui devflow secure-storage set auth_token "eyJhbGc..."
maui devflow secure-storage delete auth_token
maui devflow secure-storage clear

Note: Preference key listing uses an internal registry (keys set via the agent are tracked). Keys set directly in app code won't appear in list unless also set via the agent.

9. Platform Info & Device Features

Query read-only device and app state. These are one-shot snapshot reads.

maui devflow platform app-info         # app name, version, build, theme
maui devflow platform device-info      # manufacturer, model, OS, idiom
maui devflow platform display          # screen density, size, orientation
maui devflow platform battery          # charge level, state, power source
maui devflow platform connectivity     # WiFi/Cellular/Ethernet, network access
maui devflow platform version-tracking # version history, first launch detection
maui devflow platform permissions      # check all common permission statuses
maui devflow platform permissions camera  # check a specific permission
maui devflow platform geolocation      # current GPS coordinates
maui devflow platform geolocation --accuracy High --timeout 15

10. Device Sensors

Start, stop, and stream real-time sensor data. Sensors auto-start when streaming.

maui devflow sensors list                    # list sensors + status
maui devflow sensors start accelerometer     # start a sensor
maui devflow sensors stop accelerometer

# Stream readings to stdout (JSONL)
maui devflow sensors stream accelerometer          # Ctrl+C to stop
maui devflow sensors stream gyroscope --speed Game  # higher frequency
maui devflow sensors stream compass --duration 10  # stop after 10 seconds

Available sensors: accelerometer, barometer, compass, gyroscope, magnetometer, orientation. Speed options: UI (default), Game, Fastest, Default.

WebSocket streaming: Sensor data uses WebSocket (/ws/sensors?sensor=<name>) for real-time push. Each reading is a JSON object with sensor, timestamp, and data fields.

Command Reference

maui devflow ui (Native Agent)

Global options (work on any subcommand):

  • --agent-host (default localhost), --agent-port (auto-discovered via broker), --platform
  • --json — force JSON output. Auto-enabled when stdout is piped/redirected (TTY auto-detection).
  • --no-json — force human-readable output even when piped.
  • Env var: MAUIDEVFLOW_OUTPUT=json for persistent JSON mode.

Implicit element resolution: Commands that take an <elementId> (tap, fill, clear, focus) also accept --automationId, --type, --text, --index to resolve the element in a single call. This eliminates the query→act round-trip. The <elementId> argument is optional when resolution options are provided.

Post-action flags: tap, fill, clear accept --and-screenshot [path], --and-tree, --and-tree-depth N to return verification data alongside the action result.

CommandDescription
ui status [--window W]Agent connection status, platform, app name, window count
ui tree [--depth N] [--window W] [--fields F] [--format compact]Visual tree. --fields "id,type,text" projects specific fields. --format compact returns only id, type, text, automationId, bounds
ui query [--type T] [--automationId A] [--text T] [--selector S] [--fields F] [--format compact] [--wait-until exists|gone] [--timeout N]Find elements. --wait-until polls until condition met (default 30s timeout). --fields and --format same as tree
ui hittest <x> <y> [--window W]Find elements at a point (deepest first). Returns IDs, types, bounds
ui tap [elementId] [--automationId A] [--type T] [--text T] [--index N] [--and-screenshot [path]] [--and-tree] [--and-tree-depth N]Tap element by ID or implicit resolution
ui fill [elementId] <text> [--automationId A] [--type T] [--text T] [--index N] [--and-screenshot [path]] [--and-tree]Fill text into Entry/Editor. elementId optional when using resolution options
ui clear [elementId] [--automationId A] [--type T] [--text T] [--index N] [--and-screenshot [path]] [--and-tree]Clear text. elementId optional when using resolution options
MAUI focus [elementId] [--automationId A] [--type T] [--text T] [--index N]Set focus. elementId optional when using resolution options
MAUI assert [--id ID] [--automationId A] <property> <expected>Assert element property value. Exit 0 if match, 1 if mismatch. Ideal for verification without screenshots
MAUI screenshot [--output path.png] [--window W] [--id ID] [--selector SEL] [--overwrite] [--max-width N] [--scale native]PNG screenshot. Auto-scales to 1x logical resolution on HiDPI displays (2x, 3x). Use --scale native for full resolution. --max-width N overrides auto-scaling with explicit width. --overwrite replaces existing file
MAUI property <elementId> <prop>Read property (Text, IsVisible, FontSize, etc.)
MAUI set-property <elementId> <prop> <value>Set property (live editing — colors, text, sizes, etc.)
MAUI element <elementId>Full element JSON (type, bounds, children, etc.)
MAUI navigate <route>Shell navigation (e.g. //native, //blazor)
MAUI scroll [--element id] [--dx N] [--dy N] [--item-index N] [--group-index N] [--position P] [--window W]Scroll by delta, item index, or scroll element into view. --item-index scrolls to a specific item in CollectionView/ListView (works even for virtualized off-screen items). --position: MakeVisible (default), Start, Center, End. Delta scroll (--dy -500) uses native platform scroll for CollectionView
MAUI resize <width> <height> [--window W]Resize app window. Window is 0-based index; default first window
MAUI logs [--limit N] [--skip N] [--source S] [--follow]Fetch or stream application logs. --follow / -f streams in real-time (Ctrl+C to stop). Source: native, webview, or omit for all
MAUI recording start [--output path] [--timeout 30]Start screen recording. Default timeout 30s
MAUI recording stopStop active recording and save the video file
MAUI recording statusCheck if a recording is currently in progress
MAUI networkLive network monitor — streams HTTP requests in real-time (Ctrl+C to stop)
MAUI network list [--host H] [--method M]One-shot: dump recent captured HTTP requests
MAUI network detail <requestId>Full request/response details: headers, body, timing
MAUI network clearClear the captured request buffer
MAUI preferences list [--sharedName N]List all known preference keys and values
MAUI preferences get <key> [--type T] [--sharedName N]Get a preference value. Types: string, int, bool, double, float, long, datetime
MAUI preferences set <key> <value> [--type T] [--sharedName N]Set a preference value
MAUI preferences delete <key> [--sharedName N]Remove a preference
MAUI preferences clear [--sharedName N]Clear all preferences
MAUI secure-storage get <key>Get a secure storage value
MAUI secure-storage set <key> <value>Set a secure storage value
MAUI secure-storage delete <key>Remove a secure storage entry
MAUI secure-storage clearClear all secure storage entries
MAUI platform app-infoApp name, version, build, package, theme
MAUI platform device-infoDevice manufacturer, model, OS, idiom
MAUI platform displayScreen density, size, orientation, refresh rate
MAUI platform batteryBattery level, state, power source
MAUI platform connectivityNetwork access and connection profiles
MAUI platform version-trackingCurrent/previous/first version, build history, isFirstLaunch
MAUI platform permissions [name]Check permission status. Omit name to check all common permissions
MAUI platform geolocation [--accuracy A] [--timeout N]Get current GPS coordinates. Accuracy: Lowest, Low, Medium (default), High, Best
MAUI sensors listList available sensors and their current state (started/stopped)
MAUI sensors start <sensor> [--speed S]Start a sensor. Sensors: accelerometer, barometer, compass, gyroscope, magnetometer, orientation. Speed: UI (default), Game, Fastest, Default
MAUI sensors stop <sensor>Stop a sensor
MAUI sensors stream <sensor> [--speed S] [--duration N]Stream sensor readings via WebSocket. Duration 0 = indefinite (Ctrl+C to stop)
commands [--json]List all available commands with descriptions. --json returns machine-readable schema with command names, descriptions, and whether they mutate state

Element IDs come from MAUI tree or MAUI query. AutomationId-based elements use their AutomationId directly. Others use generated hex IDs. When multiple elements share the same AutomationId, suffixes are appended: TodoCheckBox, TodoCheckBox_1, TodoCheckBox_2, etc.

Element ID lifecycle: IDs are ephemeral — they're regenerated on each tree walk. After navigation, page changes, or significant UI updates, re-query to get fresh IDs. AutomationIds are stable across rebuilds (they come from XAML), so prefer --automationId for scripted flows.

maui devflow webview (Blazor WebView CDP)

Global options: --agent-host (default localhost), --agent-port (auto-discovered via broker). CDP commands use the same agent port — all communication goes through a single port. Use --webview <id> (or -w <id>) on any CDP command to target a specific WebView by index, AutomationId, or element ID. Default: first WebView.

CommandDescription
cdp statusCDP connection status and WebView count
cdp webviews [--json]List available CDP WebViews (index, AutomationId, ready status)
cdp snapshotAccessible DOM text (best for AI agents)
cdp sourceGet full page HTML source
cdp Browser getVersionBrowser/WebView version info
cdp Runtime evaluate <expr>Evaluate JavaScript
cdp DOM getDocumentFull DOM document
cdp DOM querySelector <sel>Find first matching element
cdp DOM querySelectorAll <sel>Find all matching elements
cdp DOM getOuterHTML <sel>Get outer HTML of element
cdp Page navigate <url>Navigate to URL
cdp Page reloadReload page
cdp Page captureScreenshotScreenshot as base64
cdp Input dispatchClickEvent <sel>Click element by CSS selector
cdp Input insertText <text>Insert text at focused element
cdp Input fill <selector> <text>Focus + fill text into element

Multi-WebView targeting: If the app has multiple BlazorWebViews, use cdp webviews to list them, then --webview <index-or-automationId> on any command to target a specific one. Example: maui devflow webview --webview 1 snapshot or maui devflow webview -w MyWebView Runtime evaluate "1+1".

maui devflow broker & discovery

The broker is a background daemon that manages port assignments for all running agents. The CLI auto-starts the broker on first use — no manual setup needed.

CommandDescription
listShow all registered agents (ID, app, platform, TFM, port, uptime)
wait [--timeout 120] [--project path] [--wait-platform P] [--json]Wait for an agent to connect. Outputs the port (or JSON with --json). Useful after dotnet build -t:Run to block until the app is ready
broker statusBroker daemon status and connected agent count
broker startStart broker daemon (auto-started by CLI — rarely needed manually)
broker stopStop broker daemon
broker logShow broker log file

maui devflow batch (Multi-Command Execution)

Execute multiple commands in one invocation via stdin. Returns JSONL responses. Use for multi-step interactions to avoid repeated port resolution.

echo "ui fill textUsername user; ui fill textPassword pwd123; ui tap buttonLogin" | maui devflow batch

For full options, JSONL format, and streaming details, see references/batch.md.

Platform Details

For detailed platform-specific setup, simulator/emulator management, and troubleshooting:

⚠️ Non-Disruptive Operation

CRITICAL: Never run commands that steal focus, move windows, simulate mouse/keyboard input, or otherwise disrupt the user's desktop. The user is likely working on the same computer.

Some platform reference notes mention osascript or xdotool. Treat those as implementation details or explicit-consent edge cases, not the default debugging workflow.

Never directly use:

  • osascript to focus/activate windows, click UI elements, send keystrokes, or change host macOS appearance without the user's approval
  • screencapture interactively (the MauiDevFlow screenshot command captures in-process instead)
  • xdotool focus/activate/key commands from the shell that affect the active window
  • Any command that moves the mouse cursor or simulates input at the OS level
  • open -a to bring apps to the foreground (use open only to launch, not to focus)

Instead: All inspection and interaction goes through maui devflow CLI commands, which communicate with the in-app agent over HTTP — no foreground focus required. Simulator-scoped commands such as xcrun simctl privacy, xcrun simctl ui <UDID> appearance ..., and xcrun simctl io screenshot are fine because they target the simulator rather than the user's desktop. If recovery requires OS-level control outside the app, ask the user to do it manually or get explicit approval before making a disruptive host-level change.

Tips

  • maui devflow list shows runtime state, not project integration. Empty list ≠ "not installed." Always check project files (grep -rl "MauiDevFlow" --include="*.csproj" .) before concluding DevFlow is unavailable.
  • maui devflow diagnose is the fastest way to check the entire chain: CLI → broker → agents → projects.
  • After launching through Aspire, always run maui devflow wait before attempting any interaction.
  • Use maui devflow batch for multi-step interactions — resolves port once, adds delays, returns structured JSONL. See references/batch.md.
  • Always use maui devflow ui screenshot — captures in-process, app does NOT need foreground focus.
  • Use AutomationId on important MAUI controls for stable element references.
  • For Blazor Hybrid, cdp snapshot is the most AI-friendly way to read page state.
  • Port discovery, multi-project setup, and custom ports: see references/setup.md.
  • Shell apps: Read AppShell.xaml to discover routes before navigating. Routes are case-sensitive and often lowercase.
  • CollectionView items: Tap the container Grid/StackLayout, not inner Labels/Images. Use --item-index to scroll to off-screen items.
  • Ambiguous --text: When text appears on multiple pages, use explicit IDs from tree.

AI Agent Best Practices

Output Format

  • Always use --json or rely on TTY auto-detection (JSON is auto-enabled when stdout is piped/redirected).
  • Set MAUIDEVFLOW_OUTPUT=json in your environment for consistent machine-readable output.
  • Use --no-json only when you specifically need human-readable output in a pipe.
  • Errors go to stderr as structured JSON: {"error": "...", "type": "RuntimeError", "retryable": false, "suggestions": [...]}.
  • Check exit codes: 0 = success, non-zero = failure.

Reducing Token Usage

  • Use --depth 15 (or higher) for MAUI tree — MAUI visual trees are deeply nested (a simple control is often at depth 10-15). Start with --depth 15; if you see truncated children, increase. After your first successful tree dump, note the depth where meaningful controls appear and reuse that depth for subsequent calls. If the tree is still too large, combine with --fields to reduce width.
  • Use --fields "id,type,text,automationId" to project only the fields you need.
  • Use --format compact for minimal tree output (id, type, text, automationId, bounds).
  • Prefer MAUI query --automationId over full tree traversal — much smaller response.
  • Use element-level screenshots (--id <elementId>) when you only need to see one control.

Adaptive Depth Learning

MAUI app trees vary in depth — a simple app might have controls at depth 8, while a complex app with Shell + NavigationPage + nested layouts might need depth 20+. After your first MAUI tree call, look at where the leaf-level controls (Button, Entry, Label) appear and remember that depth. Use it for all subsequent tree calls in the same session. If you navigate to a new page that seems deeper, bump the depth up. This avoids both truncating useful content and wasting tokens on excessively deep dumps.

Screenshot Auto-Scaling (HiDPI)

Screenshots are automatically scaled to 1x logical resolution by default. The agent detects the device's display density (2x on Retina, 3x on iPhone Pro Max, 1x on desktop) and divides the screenshot dimensions accordingly. This happens server-side before transfer.

  • No action needed — just use maui devflow ui screenshot --output screen.png and the image will be appropriately sized for AI understanding.
  • Full resolution: Use --scale native when you need pixel-perfect images (e.g., verifying exact colors, alignment, or anti-aliasing).
    maui devflow ui screenshot --output full-res.png --scale native
    
  • Explicit max width: Use --max-width N to override auto-scaling with a specific pixel width.
    maui devflow ui screenshot --output screen.png --max-width 600
    

Eliminating Round-Trips

  • Use implicit resolution instead of query-then-act:
    # Instead of: query → get ID → tap
    maui devflow ui tap --automationId "LoginButton"
    maui devflow ui fill --automationId "Username" "admin"
    maui devflow ui tap --type Button --index 0  # first Button
    
  • Use --wait-until instead of polling loops:
    maui devflow ui query --automationId "ResultsList" --wait-until exists --timeout 10
    maui devflow ui query --automationId "Spinner" --wait-until gone --timeout 30
    
  • Use post-action flags to verify in one call:
    maui devflow ui tap abc123 --and-screenshot --and-tree --and-tree-depth 5
    
  • Use MAUI assert for quick state checks:
    maui devflow ui assert --id abc123 Text "Welcome!"
    maui devflow ui assert --automationId "Counter" Text "5"
    

Element IDs

  • Element IDs are ephemeral — re-query after navigation or state changes.
  • Don't cache element IDs across multiple actions — refresh with tree or query.
  • Prefer --automationId for stable references (set in XAML).
  • Use maui devflow commands --json to discover available commands at runtime.

Shell Navigation

  • Routes are case-sensitive and come from ShellContent Route="" in XAML, not from FlyoutItem Title. Discover routes by reading AppShell.xaml:
    grep -i 'Route=' AppShell.xaml
    
  • Flyout menu items use generated IDs like FlyoutItem_D_FAULT_FlyoutItem0. Find them at the top level of the tree output. Don't try to tap Labels inside flyout items.
  • Flyout dismissal: After tapping a flyout item, the flyout may stay open. Dismiss with:
    maui devflow ui set-property <shellId> FlyoutIsPresented "false"
    

CollectionView / ListView

  • Tapping items: Always tap the item's container (Grid/StackLayout), not inner elements (Label/Image). The item template's root element handles selection.
  • Virtualization: CollectionView/ListView use item virtualization — only visible items (plus a small buffer) exist in the visual tree. Off-screen items have NO visual element. The tree shows itemCount in the CollectionView's properties so you know total items.
  • Scrolling by item index (best for reaching off-screen items):
    maui devflow ui scroll --element <cvId> --item-index 20 --position Center
    
    This works even for items not in the tree yet — the platform scrolls to materialize them.
  • Scrolling by pixel delta (for fine-grained scrolling):
    maui devflow ui scroll --element <cvId> --dy -500
    
    Uses native platform scroll (UIScrollView/RecyclerView) — works on CollectionView.
  • Workflow: Get tree → note itemCount → scroll by index → re-query tree → interact:
    maui devflow ui tree --depth 15   # CollectionView shows itemCount: 25
    maui devflow ui scroll --item-index 20
    maui devflow ui tree --depth 15   # items around index 20 now visible
    

Implicit Resolution Gotchas

  • --text searches the entire visual tree, including hidden pages (other Shell tabs). If the text is ambiguous (e.g., "+", "OK", "Cancel"), it may match a wrong element on a different page.
  • Prefer --automationId for reliable targeting. Fall back to explicit element IDs from tree/query for elements without AutomationIds.
  • Use --type + --text together to narrow matches when text alone is ambiguous.

Canonical Workflows

Login flow:

maui devflow ui query --automationId "LoginPage" --wait-until exists --timeout 15
maui devflow ui fill --automationId "UsernameField" "admin"
maui devflow ui fill --automationId "PasswordField" "password"
maui devflow ui tap --automationId "LoginButton" --and-screenshot
maui devflow ui query --automationId "HomePage" --wait-until exists --timeout 10

Shell navigation:

# Discover routes from XAML
grep -i 'Route=' AppShell.xaml                              # find route names
maui devflow ui navigate "//home"                         # navigate to a route
maui devflow ui tap FlyoutButton                          # open flyout
maui devflow ui tree --depth 3 --fields "id,type,text"    # find flyout items
maui devflow ui tap <flyoutItemId>                        # tap item
maui devflow ui set-property <shellId> FlyoutIsPresented "false"  # dismiss flyout

Element inspection:

maui devflow ui query --automationId "MyControl" --json --fields "id,type,text,bounds"
maui devflow ui element <id> --json
maui devflow ui property <id> Text

State verification:

maui devflow ui tap --automationId "IncrementButton"
maui devflow ui assert --automationId "CounterLabel" Text "1"

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