uno-agentic-support - SKILL.md Agent Skill

name: uno-agentic-support description: In-app support for agentic development of Uno Platform apps. Use when running or preparing a Uno Platform app for agent-driven execution with uno_app_start. Also use when the expected log file specified in AGENT_CONSOLE_LOG is missing or lacks "uno-agentic-support" entry, or Hot Reload / Hot Design remains visible during agent UI testing. metadata: author: https://github.com/VincentH-Net version: "1.0.2" framework: uno-platform category: agentic-support sources: https://github.com/VincentH-Net

In-app support for agentic development of Uno Platform apps

Use when using agents to run a Uno Platform app. This skill ensures that the Uno app is properly set up to support agentic development.

When the app is run by an agent - i.e. the AGENT_CONSOLE_LOG is passed in as a command-line argument or else if the AGENT_CONSOLE_LOG environment variable is set - the skill will ensure that:

comprehensive, early-start logging from the app is available in the log file specified by the agent
Uno Studio Hot Reload / Hot Design UI is disabled so it does not interfere with app UI testing and does not slow down app startup

1. When to use this skill

Select this skill for any of:

The agent is expected to run the Uno app in the current working folder
The agent did run the Uno app in the current working folder and AGENT_CONSOLE_LOG was passed in as a command-line argument or the AGENT_CONSOLE_LOG environment variable is set, and any of below is true:
- the specified log file was not created or does not contain a log entry that mentions uno-agentic-support
- the specified log file contains a log entry that mentions uno-agentic-support: true but the Uno app is still showing the Hot Reload / Hot Design UI when launched by the agent

2. STOP — prerequisite gate before applying edits

Before applying edits from this skill, run this prerequisite check in the current working folder and act on the result.

A Uno Platform app project must exist in the working folder. Find the Uno app .csproj in the working folder. A valid Uno app project must use the Uno SDK and contain App.xaml.cs in or under the project folder.

If the Uno Platform app project is not found, report this to the user and STOP.

3. Ensure App.xaml.cs is wired up for agentic development

In App.xaml.cs:

Adapt, don't paste blindly. Uno templates and application host setup vary. Preserve existing app behavior, logging providers, filters, host configuration, namespaces, and comments unless they directly conflict with agentic support.

Ensure that the App class includes these code snippets:

#if DEBUG
    readonly bool startedByAgent;
#endif

#if DEBUG
    void InitializeAgentSupport(string? agentConsoleLogPath)
    {
        if (agentConsoleLogPath is not null)
        {
            var stream = new FileStream(agentConsoleLogPath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
            #pragma warning disable CA2000 // Dispose objects before losing scope
            var writer = new StreamWriter(stream) { AutoFlush = true };
            #pragma warning restore CA2000 // Dispose objects before losing scope
            Console.SetOut(writer);
            Console.SetError(writer);
        }
        // Make sure that loggings made before the application host is initialized are captured
        LogExtensionPoint.AmbientLoggerFactory = LoggerFactory.Create(ConfigureAppLogging);
        #if HAS_UNO
            Uno.UI.Adapter.Microsoft.Extensions.Logging.LoggingAdapter.Initialize();
        #endif
    }

    static string? ResolveAgentConsoleLogPath()
    {
        const string key = "AGENT_CONSOLE_LOG";

        string prefix = key + "=";
        foreach (string arg in Environment.GetCommandLineArgs())
        {
            if (arg.StartsWith(prefix, StringComparison.Ordinal))
            {
                string value = arg[prefix.Length..];
                if (!string.IsNullOrEmpty(value)) return value;
            }
        }

        string? fromEnv = Environment.GetEnvironmentVariable(key);
        return string.IsNullOrEmpty(fromEnv) ? null : fromEnv;
    }
#endif

    void ConfigureAppLogging(ILoggingBuilder logBuilder)
    {
        _ = logBuilder.SetMinimumLevel(LogLevel.Warning);
    #if DEBUG
        // Set the default log level for the app's own namespace to Debug
        _ = logBuilder.AddFilter(GetType().Namespace!.Split('.')[0], LogLevel.Debug);
        // Make sure that agents receive the logs in the console
        if (startedByAgent) _ = logBuilder.AddConsole();

        // Uno Platform namespace filter groups
        // Uncomment individual methods to see more detailed logging
        //// Generic Xaml events
        //logBuilder.XamlLogLevel(LogLevel.Debug);
        //// Layout specific messages
        //logBuilder.XamlLayoutLogLevel(LogLevel.Debug);
        //// Storage messages
        //logBuilder.StorageLogLevel(LogLevel.Debug);
        //// Binding related messages
        //logBuilder.XamlBindingLogLevel(LogLevel.Debug);
        //// Binder memory references tracking
        //logBuilder.BinderMemoryReferenceLogLevel(LogLevel.Debug);
        //// DevServer and HotReload related
        //logBuilder.HotReloadCoreLogLevel(LogLevel.Information);
        //// Debug JS interop
        //logBuilder.WebAssemblyLogLevel(LogLevel.Debug);
    #endif
    }

The App constructor must begin with below statements. Add them if not present, or move them to the top of the constructor if present but not at the top:

#if DEBUG
    string? agentConsoleLogPath = ResolveAgentConsoleLogPath();
    startedByAgent = agentConsoleLogPath is not null;
    InitializeAgentSupport(agentConsoleLogPath);
    var logger = this.Log();
    if (logger.IsEnabled(LogLevel.Debug)) logger.LogDebug("Application Launched in DEBUG mode. uno-agentic-support: {StartedByAgent}", startedByAgent);
#endif

In the OnLaunched method:
- The application host configuration must call .UseLogging() with configure: ConfigureAppLogging and enableUnoLogging: true.
- If .UseLogging() already exists, preserve existing app-specific logging setup and adapt it so ConfigureAppLogging still runs and Uno logging remains enabled.
- If .UseLogging() is missing, add it in the existing host configuration chain:
```
    .UseLogging(
        configure: ConfigureAppLogging,
        enableUnoLogging: true
    )
```
- In ConfigureAppLogging, preserve any existing app-specific filters and providers. Add the agent-specific pieces only if they are missing:
  - logBuilder.SetMinimumLevel(LogLevel.Warning);
  - logBuilder.AddFilter(GetType().Namespace!.Split('.')[0], LogLevel.Debug);
  - if (startedByAgent) logBuilder.AddConsole();
- If an existing UseStudio call is present, replace it with:
```
    #if DEBUG
    MainWindow.UseStudio(showHotReloadIndicator: !startedByAgent, launchHotDesignOnStart: !startedByAgent);
    #endif
```

4. Validate

After editing:

Build or start the app using the repository's active Build and Run directive; pass in AGENT_CONSOLE_LOG=<new-log-path>.
Confirm the log file exists.
Confirm it contains uno-agentic-support:. Match this case-insensitively.
Confirm Hot Reload / Hot Design UI is not visible.