MAUI AI Debugging

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

Prerequisites

Install (or update) the CLI tool and ensure it's the latest version:

dotnet tool install --global Redth.MauiDevFlow.CLI || dotnet tool update --global Redth.MauiDevFlow.CLI

For platform-specific tools: dotnet tool install --global androidsdk.tool (Android) and dotnet tool install --global appledev.tools (iOS/Mac).

Keep the skill up to date: Run maui-devflow update-skill periodically (or at the start of a new session) to download the latest version of this skill from GitHub. The skill evolves alongside the CLI — outdated skill files may reference removed options or miss new commands.

Integrating MauiDevFlow into a MAUI App

For complete setup instructions including NuGet packages, MauiProgram.cs registration, Blazor script tag, Mac Catalyst entitlements, and Android port forwarding, see references/setup.md.

Quick summary:

1. •Add NuGet packages (Redth.MauiDevFlow.Agent, and Redth.MauiDevFlow.Blazor for Blazor Hybrid)
2. •Register in MauiProgram.cs inside #if DEBUG
3. •Create .mauidevflow with a random port (see below)
4. •For Blazor Hybrid: add <script src="chobitsu.js"></script> to wwwroot/index.html
5. •For Mac Catalyst: ensure network.server entitlement
6. •For Android: run adb reverse for the configured port

Port configuration: If no .mauidevflow exists in the project directory, create one with a random port between 9223–9899 to avoid collisions with other projects:

{
  "port": <pick a random number between 9223 and 9899>
}

Both the build and the CLI read this file automatically — no need to pass -p:MauiDevFlowPort or --agent-port flags. Run CLI commands from the project directory for automatic detection. If the file already exists, use the port specified in it.

Core Workflow

1. Ensure a Device/Simulator/Emulator is Running

iOS Simulator:

xcrun simctl list devices booted                              # check booted sims
xcrun simctl boot <UDID>                                      # boot if needed
apple simulator list --booted                                 # alternative
apple simulator boot <UDID>                                   # alternative

Android Emulator:

android avd list                                              # list AVDs
android avd start --name <avd-name>                           # start emulator
adb devices                                                   # verify connected

Mac Catalyst: No device setup needed — runs as desktop app.

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.

# Read TargetFrameworks from the .csproj or Directory.Build.props
grep -i 'TargetFrameworks' *.csproj Directory.Build.props 2>/dev/null

Look for entries like net9.0-ios;net9.0-android;net9.0-maccatalyst. Use that version (e.g. net9.0) in all build commands below. The examples use $TFM as a placeholder.

3. Build and Deploy

CRITICAL: -t:Run keeps the process alive until the app exits. Run it in background (async bash) or a separate shell — do NOT run it synchronously and expect to execute subsequent commands in the same shell.

# iOS Simulator (run in background/async shell)
dotnet build -f $TFM-ios -t:Run -p:_DeviceName=:v2:udid=<UDID>

# Android Emulator (run in background/async shell)
dotnet build -f $TFM-android -t:Run

# Mac Catalyst (run in background/async shell)
dotnet build -f $TFM-maccatalyst -t:Run

Replace $TFM with the actual version detected in step 2 (e.g. net9.0, net10.0). Build + Run can take 30-120+ seconds. Use initial_wait: 120 or higher for async monitoring. Wait for "Running app..." or similar output before proceeding to connectivity checks.

Device/simulator compatibility: The TFM compile target (e.g. net10.0-android targets API 36, net10.0-ios targets iOS 26) does NOT mean you need a matching emulator/simulator version. Apps run on any device at or above SupportedOSPlatformVersion (check Directory.Build.props or .csproj). Use whatever emulator/simulator is available — don't waste time finding one that matches the TFM.

For Android emulators, set up port forwarding after deploy:

adb reverse tcp:9223 tcp:9223    # Agent + CDP (single port)

4. Verify Connectivity

maui-devflow MAUI status          # Agent connection + CDP readiness
maui-devflow cdp status           # CDP-specific connection check

5. Inspect and Interact

See Command Reference below for the full command set.

Typical inspection flow:

1. •maui-devflow MAUI tree — see the full visual tree with element IDs, types, text, bounds
2. •maui-devflow MAUI query --automationId "MyButton" — find specific elements
3. •maui-devflow MAUI element <id> — get full details (type, bounds, visibility, children)
4. •maui-devflow MAUI property <id> Text — read any property by name
5. •maui-devflow MAUI screenshot --output screen.png — visual verification

Debugging styling/layout with property inspection: Use property to verify runtime values without relying solely on screenshots:

maui-devflow MAUI property <id> BackgroundColor    # verify dark mode colors
maui-devflow MAUI property <id> TextColor          # check text visibility
maui-devflow MAUI property <id> IsVisible          # check element visibility
maui-devflow MAUI property <id> Width              # verify layout sizing
maui-devflow MAUI property <id> Opacity            # check transparency

Combine tree + property for systematic debugging: get element IDs from tree, then inspect specific properties. This is more reliable than screenshots for verifying exact color values, font sizes, and layout metrics.

Live editing native MAUI elements (no rebuild needed): Use set-property to change any writable property at runtime. Changes are immediate and visible — experiment with colors, sizes, text, and layout before committing to code.

# Change text
maui-devflow MAUI set-property <id> Text "New Title"

# Change colors (named colors, hex, or rgba)
maui-devflow MAUI set-property <id> TextColor "Tomato"
maui-devflow MAUI set-property <id> BackgroundColor "#2a1f5e"
maui-devflow MAUI set-property <id> TextColor "DodgerBlue"

# Change sizing and layout
maui-devflow MAUI set-property <id> FontSize "24"
maui-devflow MAUI set-property <id> Padding "10,5,10,5"
maui-devflow MAUI set-property <id> Opacity "0.5"
maui-devflow MAUI set-property <id> WidthRequest "200"

# Toggle visibility
maui-devflow MAUI set-property <id> IsVisible "false"

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 MAUI fill <entryId> "text" — type into Entry/Editor fields
2. •maui-devflow MAUI tap <buttonId> — tap buttons, checkboxes, list items
3. •maui-devflow MAUI clear <entryId> — clear text fields
4. •Take screenshot to verify result

Blazor WebView (if applicable):

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

Live CSS/DOM editing in Blazor (no rebuild needed): Use Runtime evaluate to experiment with styles and DOM changes in-place before committing to code. Changes are immediate and non-destructive — lost on page reload.

# Change an element's style directly
maui-devflow cdp Runtime evaluate "document.querySelector('h1').style.color = 'tomato'"

# Bulk-update elements
maui-devflow cdp Runtime evaluate "document.querySelectorAll('.todo-item').forEach(el => el.style.borderRadius = '20px')"

# Set or override CSS variables
maui-devflow cdp Runtime evaluate "document.documentElement.style.setProperty('--bg-color', '#1a1a2e')"

# Inject a whole style rule (great for testing complex changes)
maui-devflow cdp Runtime evaluate "document.head.insertAdjacentHTML('beforeend', '<style>.btn { background: linear-gradient(135deg, #667eea, #764ba2) !important; }</style>')"

# Change element text to preview copy changes
maui-devflow cdp Runtime evaluate "document.querySelector('h1').textContent = 'New Title'"

Reading computed styles (verify actual rendered values):

maui-devflow cdp Runtime evaluate "getComputedStyle(document.querySelector('.my-class')).backgroundColor"
maui-devflow cdp Runtime evaluate "getComputedStyle(document.querySelector('.my-class')).borderRadius"
maui-devflow cdp Runtime evaluate "window.matchMedia('(prefers-color-scheme: dark)').matches"

Use computed style reads to verify exact color values, font sizes, and layout metrics — more reliable than screenshots for precise debugging.

6. Reading Application Logs

MauiDevFlow automatically captures all Microsoft.Extensions.Logging (ILogger) output to rotating log files on the device. This means any ILogger<T> calls in the app's code (or in libraries) are available for remote retrieval — invaluable for debugging.

maui-devflow MAUI logs                   # fetch 100 most recent log entries
maui-devflow MAUI logs --limit 50        # fetch 50 entries
maui-devflow MAUI logs --skip 100        # skip newest 100, get next batch

Output is color-coded by level (red=Critical/Error, yellow=Warning, green=Info, gray=Debug/Trace). Each entry includes timestamp, log level, category (logger name), and message.

Debugging workflow with logs:

1. •Reproduce the issue (tap a button, navigate, etc.)
2. •maui-devflow MAUI logs --limit 20 — check recent log entries for errors or warnings
3. •If needed, add temporary ILogger calls to the app code for more detail:
   csharp

   _logger.LogInformation("Button tapped, item count: {Count}", items.Count);
   _logger.LogWarning("Unexpected state: {State}", currentState);
   

4. •Rebuild, redeploy, reproduce, and fetch logs again

Log configuration (in AddMauiDevFlowAgent options):

• •EnableFileLogging (default: true) — toggle file logging
• •MaxLogFileSize (default: 1 MB) — max size per log file before rotation
• •MaxLogFiles (default: 5) — number of rotated files to keep

The agent also exposes logs via REST: GET /api/logs?limit=N&skip=N returns a JSON array.

7. Live Preview Before Rebuilding

Before rebuilding, use live editing to prototype small changes directly on the running app. This skips the build→deploy cycle entirely — test colors, text, sizes, and styles in seconds instead of minutes. Make several tweaks in a batch, evaluate the result visually, then commit only the changes you're happy with to code.

Workflow: tweak → evaluate → tweak → ... → commit to code → rebuild once

For native MAUI elements — use set-property:

maui-devflow MAUI set-property <id> TextColor "DodgerBlue"
maui-devflow MAUI set-property <id> FontSize "20"
maui-devflow MAUI set-property <id> Padding "12,8,12,8"
maui-devflow MAUI screenshot --output preview.png    # check the result

For Blazor Hybrid pages — use cdp Runtime evaluate:

maui-devflow cdp Runtime evaluate "document.querySelector('h1').style.color = 'tomato'"
maui-devflow cdp Runtime evaluate "document.documentElement.style.setProperty('--primary', '#667eea')"
maui-devflow cdp Runtime evaluate "document.querySelector('.card').style.borderRadius = '16px'"
maui-devflow cdp Page captureScreenshot                # check the result

Mix both on apps with native + Blazor tabs — tweak native properties on one tab and Blazor styles on another, all without a single rebuild. Once satisfied, apply the changes to source code and rebuild once.

8. Rebuild

After live preview confirms the desired look, edit source code to make changes permanent. The full cycle: edit code → dotnet build -f $TFM-<platform> -t:Run ... → maui-devflow MAUI status → inspect. If the build fails, see Troubleshooting below.

Command Reference

maui-devflow MAUI (Native Agent)

Global options: --agent-host (default localhost), --agent-port (default 9223), --platform.

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.

maui-devflow cdp (Blazor WebView CDP)

Global options: --agent-host (default localhost), --agent-port (default 9223). CDP commands use the same agent port — all communication goes through a single port.

Agent REST API (Direct HTTP)

The agent exposes JSON endpoints on port 9223 (configurable via -p:MauiDevFlowPort):

Platform Details

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

• •Setup & Installation: See references/setup.md
• •iOS / Mac Catalyst: See references/ios-and-mac.md
• •Android: See references/android.md

Multi-Project / Custom Ports

The default port is 9223. For custom ports, create a .mauidevflow file in the project directory. Both the MSBuild targets and the CLI read this file automatically:

{
  "port": 9225
}

With this file in place:

• •Build: dotnet build -f $TFM-maccatalyst -t:Run — automatically uses port 9225
• •CLI: maui-devflow MAUI status — automatically uses port 9225 (reads from cwd)
• •Android: match the port: adb reverse tcp:9225 tcp:9225

No need to pass -p:MauiDevFlowPort or --agent-port — the config file handles it.

Port priority: Code-set options.Port > MSBuild -p:MauiDevFlowPort > .mauidevflow > Default 9223.

The CLI looks for .mauidevflow in the current working directory. Run CLI commands from the project directory (where the file lives) for automatic port detection.

Troubleshooting

Connection Refused / Cannot Connect

If maui-devflow MAUI status fails with connection refused:

1. •App not running? Verify the app launched: check the build output for errors.
2. •Wrong port? Ensure .mauidevflow port matches between build and CLI. Run CLI from the project directory so it auto-detects the config file.
3. •Port already in use? Another process may hold the port. Check with:
   bash

   lsof -i :<port>       # macOS/Linux
   

   Pick a different port in .mauidevflow and rebuild.
4. •Android? Did you run adb reverse tcp:<port> tcp:<port>? Re-run it after each deploy.
5. •Mac Catalyst? Check entitlements include network.server (see setup.md step 5).

Build Failures

Missing workloads:

error NETSDK1147: To build this project, the following workloads must be installed: maui-ios

Fix: dotnet workload install maui (installs all MAUI workloads).

SDK version mismatch:

error : The current .NET SDK does not support targeting .NET 10.0

Fix: Install the required .NET SDK version, or check global.json for version pins.

Android SDK not found:

error XA0000: Could not find Android SDK

Fix: Install Android SDK via android sdk install or set $ANDROID_HOME.

iOS provisioning / signing errors: Fix: For simulators, ensure no signing is configured (default). For devices, set up provisioning profiles via apple appstoreconnect profiles list.

General build failure recovery:

1. •dotnet clean then retry the build
2. •Delete bin/ and obj/ directories: rm -rf bin obj then rebuild
3. •Check the full build output (not just the last error) — earlier warnings often reveal the root cause

CDP Not Connecting (Blazor Hybrid)

If maui-devflow cdp status fails but MAUI status works:

1. •Missing script tag? Ensure <script src="chobitsu.js"></script> is in wwwroot/index.html
2. •Blazor not initialized? Navigate to a Blazor page first, then retry
3. •Check app logs: maui-devflow MAUI logs --limit 20 — look for [BlazorDevFlow] errors

Mac Catalyst: Repeated Permission Dialogs on Rebuild

If macOS prompts "App would like to access your Documents folder" on every rebuild:

Cause: TCC permissions are tied to the app's code signature. Ad-hoc Debug builds produce a different signature each rebuild → macOS forgets the grant and re-prompts. This happens even with App Sandbox disabled.

Fix: Don't access TCC-protected directories (~/Documents, ~/Downloads, ~/Desktop, or dotfiles like ~/.myapp/ in the home root) programmatically. Instead use:

• •Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) → ~/Library/Application Support/ (not TCC-protected)
• •NSOpenPanel/NSSavePanel for user-initiated file access (grants automatic TCC exemption)

If you can't avoid TCC paths, sign Debug builds with a stable Apple Development certificate so the code signature stays consistent across rebuilds.

Tips

• •Use AutomationId on important MAUI controls for stable element references.
• •The visual tree only reflects what's currently rendered. Off-screen items in CollectionView may not appear until scrolled into view.
• •Shell navigation: Use maui-devflow MAUI navigate "//route" for Shell-based apps. Routes are defined in AppShell.xaml via Route property on ShellContent elements.
• •For Blazor Hybrid, cdp snapshot is the most AI-friendly way to read page state.
• •Build times: Mac Catalyst ~5-10s, iOS ~30-60s, Android ~30-90s. Set appropriate timeouts.
• •After Android deploy, always run adb reverse for port forwarding (match the port in .mauidevflow or default 9223).
• •Property inspection is more reliable than screenshots for verifying exact runtime values (colors, sizes, visibility). Use tree → property workflow for systematic debugging.
• •Application logs are captured automatically from ILogger. Use MAUI logs to fetch them remotely. Add temporary ILogger calls for extra debug output, then fetch logs after reproducing issues. This is often faster than attaching a debugger.
• •Single port: Both MAUI native and CDP commands share port 9223 (configurable). No separate WebSocket endpoint needed.