williamzujkowski/C# .NET Tooling Specialist

Purpose & When-To-Use

Trigger conditions:

• Starting a new C# .NET project requiring modern tooling
• Creating ASP.NET Core web APIs or Blazor applications
• Building cross-platform console applications or libraries
• Setting up .NET MAUI mobile applications
• Creating NuGet packages for distribution
• Migrating .NET Framework projects to .NET Core/5+

Not for:

• Legacy .NET Framework 4.x projects (use older MSBuild templates)
• Unity game development (use Unity's project templates)
• Xamarin projects (migrated to .NET MAUI)

Pre-Checks

Time normalization:

• Compute NOW_ET using NIST/time.gov semantics (America/New_York, ISO-8601)
• Use NOW_ET for all citation access dates

Input validation:

• project_type must be one of: library, console, web-api, blazor, wpf, maui
• dotnet_version must be one of: 6.0, 7.0, 8.0
• test_framework must be one of: xunit, nunit, mstest
• project_name must be valid .NET identifier (PascalCase recommended)

Source freshness:

• .NET docs must be accessible accessed 2025-10-26
• ASP.NET Core docs must be accessible accessed 2025-10-26
• xUnit docs must be accessible accessed 2025-10-26
• NuGet docs must be accessible accessed 2025-10-26

Procedure

T1: Basic Project Structure (≤2k tokens)

Fast path for common cases:

1. Directory Layout Generation

ProjectName/ src/ ProjectName/ ProjectName.csproj Class1.cs tests/ ProjectName.Tests/ ProjectName.Tests.csproj UnitTest1.cs ProjectName.sln .gitignore README.md

1. Core .csproj accessed 2025-10-26

xml <Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <Nullable>enable</Nullable> <ImplicitUsings>enable</ImplicitUsings> <LangVersion>latest</LangVersion> </PropertyGroup>

<ItemGroup> <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.556"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets> </PackageReference> </ItemGroup> </Project>

1. Solution File (.sln)

Microsoft Visual Studio Solution File, Format Version 12.00 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProjectName", "src\ProjectName\ProjectName.csproj", "{GUID}" EndProject Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProjectName.Tests", "tests\ProjectName.Tests\ProjectName.Tests.csproj", "{GUID}" EndProject

Decision: If only basic scaffolding needed → STOP at T1; otherwise proceed to T2.

T2: Full Tooling Setup (≤6k tokens)

Extended configuration with testing and web frameworks:

1. Testing Framework Configuration

xUnit accessed 2025-10-26 xml <Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <IsPackable>false</IsPackable> <IsTestProject>true</IsTestProject> </PropertyGroup>

<ItemGroup> <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" /> <PackageReference Include="xunit" Version="2.7.0" /> <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets> </PackageReference> <PackageReference Include="Moq" Version="4.20.70" /> <PackageReference Include="FluentAssertions" Version="6.12.0" /> <PackageReference Include="coverlet.collector" Version="6.0.0"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets> </PackageReference> </ItemGroup>

<ItemGroup> <ProjectReference Include="..\..\src\ProjectName\ProjectName.csproj" /> </ItemGroup> </Project>

NUnit (alternative) accessed 2025-10-26 xml <ItemGroup> <PackageReference Include="NUnit" Version="4.1.0" /> <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" /> <PackageReference Include="NUnit.Analyzers" Version="4.1.0" /> </ItemGroup>

1. Code Quality and Analyzers

StyleCop + Roslyn Analyzers accessed 2025-10-26 xml <ItemGroup> <PackageReference Include="StyleCop.Analyzers" Version="1.2.0-beta.556"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets> </PackageReference> <PackageReference Include="SonarAnalyzer.CSharp" Version="9.23.0.88079"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets> </PackageReference> </ItemGroup>

.editorconfig: ini # Top-most EditorConfig file root = true

.cs] # Code style rules dotnet_sort_system_directives_first = true csharp_style_var_for_built_in_types = true csharp_style_var_when_type_is_apparent = true

# Naming conventions dotnet_naming_rule.interfaces_should_be_prefixed_with_i.severity = warning dotnet_naming_rule.interfaces_should_be_prefixed_with_i.symbols = interface dotnet_naming_rule.interfaces_should_be_prefixed_with_i.style = begins_with_i

# StyleCop rules dotnet_diagnostic.SA1633.severity = none # File header dotnet_diagnostic.SA1200.severity = none # Using directives placement

1. ASP.NET Core Web API

Minimal API accessed 2025-10-26 xml <Project Sdk="Microsoft.NET.Sdk.Web"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <Nullable>enable</Nullable> <ImplicitUsings>enable</ImplicitUsings> </PropertyGroup>

<ItemGroup> <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.4" /> <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" /> </ItemGroup> </Project>

Program.cs (minimal API): csharp var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer(); builder.Services.AddSwaggerGen();

var app = builder.Build();

if (app.Environment.IsDevelopment()) { app.UseSwagger(); app.UseSwaggerUI(); }

app.UseHttpsRedirection();

app.MapGet("/api/health", () => Results.Ok(new { status = "healthy" })) .WithName("GetHealth") .WithOpenApi();

app.Run();

1. Blazor WebAssembly

xml <Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> </PropertyGroup>

<ItemGroup> <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="8.0.4" /> <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="8.0.4" PrivateAssets="all" /> </ItemGroup> </Project>

T3: Advanced Configuration (≤12k tokens)

Deep configuration for NuGet packaging and production:

1. NuGet Package Configuration accessed 2025-10-26

xml <Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <GeneratePackageOnBuild>true</GeneratePackageOnBuild> <PackageId>CompanyName.ProjectName</PackageId> <Version>1.0.0</Version> <Authors>Your Name</Authors> <Company>Company Name</Company> <Description>Package description</Description> <PackageTags>tag1;tag2;tag3</PackageTags> <PackageLicenseExpression>MIT</PackageLicenseExpression> <PackageProjectUrl>https://github.com/user/repo</PackageProjectUrl> <RepositoryUrl>https://github.com/user/repo</RepositoryUrl> <RepositoryType>git</RepositoryType> <PublishRepositoryUrl>true</PublishRepositoryUrl> <EmbedUntrackedSources>true</EmbedUntrackedSources> <IncludeSymbols>true</IncludeSymbols> <SymbolPackageFormat>snupkg</SymbolPackageFormat> </PropertyGroup>

<ItemGroup> <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" /> </ItemGroup> </Project>

1. Multi-Target Framework

xml <PropertyGroup> <TargetFrameworks>net6.0;net7.0;net8.0</TargetFrameworks> </PropertyGroup>

<ItemGroup Condition="'$(TargetFramework)' == 'net6.0'"> <PackageReference Include="System.Text.Json" Version="6.0.0" /> </ItemGroup>

<ItemGroup Condition="'$(TargetFramework)' == 'net8.0'"> <PackageReference Include="System.Text.Json" Version="8.0.0" /> </ItemGroup>

1. Native AOT Publishing accessed 2025-10-26

xml <PropertyGroup> <PublishAot>true</PublishAot> <InvariantGlobalization>true</InvariantGlobalization> <JsonSerializerIsReflectionEnabledByDefault>false</JsonSerializerIsReflectionEnabledByDefault> </PropertyGroup>

Publish command: bash dotnet publish -c Release -r linux-x64 --self-contained

1. Docker Configuration

Dockerfile (multi-stage): dockerfile FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build WORKDIR /src COPY "src/ProjectName/ProjectName.csproj", "src/ProjectName/"] RUN dotnet restore "src/ProjectName/ProjectName.csproj" COPY . . WORKDIR "/src/src/ProjectName" RUN dotnet build "ProjectName.csproj" -c Release -o /app/build

FROM build AS publish RUN dotnet publish "ProjectName.csproj" -c Release -o /app/publish

FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS final WORKDIR /app EXPOSE 8080 COPY --from=publish /app/publish . ENTRYPOINT "dotnet", "ProjectName.dll"]

.dockerignore: **/bin **/obj **/out **/.vs **/.vscode

1. CI/CD Pipeline (GitHub Actions)

.github/workflows/dotnet.yml name: .NET CI

on: push: branches: main ] pull_request: branches: main ]

jobs: build: runs-on: ubuntu-latest steps:

• uses: actions/checkout@v4
• name: Setup .NET

uses: actions/setup-dotnet@v4 with: dotnet-version: 8.0.x

• name: Restore dependencies

run: dotnet restore

• name: Build

run: dotnet build --no-restore

• name: Test

run: dotnet test --no-build --verbosity normal --collect:"XPlat Code Coverage"

• name: Upload coverage

uses: codecov/codecov-action@v4

1. Solution-Level Configuration

Directory.Build.props (applies to all projects): xml <Project> <PropertyGroup> <TreatWarningsAsErrors>true</TreatWarningsAsErrors> <AnalysisMode>AllEnabledByDefault</AnalysisMode> <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild> <EnableNETAnalyzers>true</EnableNETAnalyzers> </PropertyGroup> </Project>

Decision Rules

Project Type Selection:

• library: Class library for NuGet distribution, multi-targeting
• console: Command-line application, single executable
• web-api: ASP.NET Core minimal API or MVC for REST services
• blazor: Blazor WebAssembly or Server for SPAs
• wpf: Windows desktop application (Windows-only)
• maui: Cross-platform mobile and desktop (.NET MAUI)

Test Framework Selection:

• xUnit: Modern, recommended for new projects, parallel execution
• NUnit: Mature, feature-rich, parameterized tests
• MSTest: Microsoft's framework, Visual Studio integration

Abort Conditions:

• Invalid project_name (contains spaces, special chars) → error
• Conflicting frameworks (WPF + MAUI) → error
• Unsupported .NET version → error

.NET Version Selection:

• Use .NET 8.0 for new projects (LTS with long-term support)
• .NET 6.0 for compatibility with older systems (LTS)
• .NET 7.0 for latest features (standard support)

Output Contract

Schema (JSON):

json
{
  "project_name": "string",
  "project_type": "library | console | web-api | blazor | wpf | maui",
  "dotnet_version": "string",
  "test_framework": "xunit | nunit | mstest",
  "structure": {
    "directories": ["string"],
    "files": {
      "path/to/file": "file content (string)"
    }
  },
  "commands": {
    "restore": "string",
    "build": "string",
    "test": "string",
    "run": "string",
    "publish": "string"
  },
  "next_steps": ["string"],
  "timestamp": "ISO-8601 string (NOW_ET)"
}

Required Fields:

• All fields mandatory
• File contents must be syntactically valid (XML, C#, JSON)
• Include inline comments explaining configuration choices

Examples

Quick Start: C# Library (26 lines)

csharp
// examples/LibraryExample.cs
namespace Example.Utils;

public sealed class TextAnalyzer
{
    public record AnalysisResult(int Length, int WordCount, DateTime Analyzed);

    private readonly List<string> _history = new();

    public AnalysisResult Analyze(string text)
    {
        ArgumentException.ThrowIfNullOrWhiteSpace(text);
        _history.Add(text);
        var wordCount = text.Split(' ', StringSplitOptions.RemoveEmptyEntries).Length;
        return new AnalysisResult(text.Length, wordCount, DateTime.UtcNow);
    }

    public IReadOnlyList<string> GetHistory() => _history.AsReadOnly();

    public void Clear() => _history.Clear();
}

Additional Examples:

• CLI Tool: examples/CliExample.cs (22 lines) - System.CommandLine, async/await, file I/O
• Minimal API: examples/ApiExample.cs (30 lines) - ASP.NET Core endpoints, concurrent collections

Template Resources (see resources/)

• .csproj: Library.csproj / Console.csproj / WebApi.csproj
• Testing: Tests.csproj with xUnit, Moq, FluentAssertions / ExampleTest.cs
• Packaging: NuGetPackage.csproj - complete NuGet metadata and SourceLink

Quality Gates

Token Budgets:

• T1: ≤2k tokens (basic structure + .csproj + .sln)
• T2: ≤6k tokens (testing, analyzers, ASP.NET Core, Blazor)
• T3: ≤12k tokens (NuGet packaging, multi-targeting, Docker, CI/CD, native AOT)

Safety:

• No hardcoded API keys or secrets
• .gitignore includes bin/, obj/, .vs/, .user files
• Roslyn analyzers configured to catch security issues

Auditability:

• All configurations cite official Microsoft documentation
• Version constraints explicit
• Generation timestamp included

Determinism:

• Same inputs → identical structure
• Versions pinned where appropriate
• No randomness in generation

Performance:

• T1 generation: <1 second
• T2 generation: <3 seconds
• T3 generation: <5 seconds

Resources

Official Documentation (accessed 2025-10-26):

1. .NET Documentation - Core .NET reference
2. ASP.NET Core Documentation - Web framework
3. xUnit Getting Started - Testing framework
4. NuGet Documentation - Package management
5. StyleCop Analyzers - Code quality
6. Blazor Documentation - WebAssembly/Server
7. .NET MAUI Documentation - Cross-platform apps

Testing:

• NUnit - Alternative testing framework
• MSTest - Microsoft testing framework
• Moq - Mocking library
• FluentAssertions - Assertion library

Build Tools:

• MSBuild - Build engine
• Native AOT - Ahead-of-time compilation

Best Practices:

• C# Coding Conventions - Style guide
• .NET Design Guidelines - API design