.NET Framework 4.8 Master Architect Skill

The only production-ready multi-agent orchestrator for .NET Framework 4.8/4.8.1. Six domain specialists work together to maintain, secure, test, and modernize legacy enterprise code — without the big bang.

Why This Exists

.NET Framework 4.8 powers millions of enterprise apps in 2026: banking cores, hospital systems, government portals, factory SCADA. Most AI coding skills treat it as an afterthought. This one doesn't.

The problem with monolithic skills: Asking one AI to be expert in WPF threading, WebForms ViewState, EF6 query plans, WCF bindings, and legacy test coverage simultaneously produces shallow, often wrong answers.

Our solution: An Orchestrator that routes your request to the right specialist — just like a real architecture team.

┌─────────────────────────────────────────┐
│           [Your Request]                │
│  "Refactor this WinForms app + add      │
│   tests + migrate WCF to gRPC"         │
└──────────────────┬──────────────────────┘
                   │
        ┌──────────▼──────────┐
        │    Orchestrator     │  ← Classifies intent
        │   (SKILL.md main)   │
        └──────────┬──────────┘
                   │
    ┌──────────────┼──────────────┐
    │              │              │
    ▼              ▼              ▼
[Desktop]      [Test]        [Modernize]
  Agent         Agent          Agent
  (MVVM)    (TDD + Mock)  (Strangler Fig)
    │              │              │
    └──────────────┼──────────────┘
                   │
        ┌──────────▼──────────┐
        │  Synthesized Plan   │  ← One coherent answer
        │  + Code + Tests     │
        └─────────────────────┘

The 6 Specialists

Agent	Trigger	Deep Expertise
🖥️ Desktop	WPF, WinForms, XAML, MVVM, MVP	Dispatcher.Invoke, WeakEventManager, GDI+ leaks, COM interop, Prism/Caliburn.Micro
🌐 Web	ASP.NET, MVC 5, WebForms, IIS	Routing, ViewState, output caching, IIS thread tuning, WebForms→Blazor migration
🗄️ Data	EF6, ADO.NET, Dapper, SQL	Compiled queries, AsNoTracking, connection pooling, N+1 prevention, Repository+UoW
🔒 Security	TLS, JWT, OAuth, OWASP	TLS 1.2 enforcement, System.IdentityModel.Tokens.Jwt, OWIN Katana, DPAPI, XXE prevention
🧪 Test	NUnit, xUnit, Moq, coverage	TDD for new code, characterization tests for legacy, integration tests with LocalDB rollback
🚀 Modernize	Migration, .NET Standard, CoreWCF	Strangler Fig pattern, YARP gateway, EF6→EF Core coexistence, gRPC adoption

What You Get

• 36 files — 1 orchestrator, 6 sub-agents, 15 code snippets, 4 audit prompts, 2 docs, 8 platform configs
• Zero hallucinations — Every claim fact-checked against .NET 4.8 runtime limits (C# 7.3, no TLS 1.3, no Span)
• Test-first — The only .NET 4.8 skill that generates characterization tests before allowing legacy refactors
• Migration-ready — Clear paths from WebForms→Blazor, WCF→gRPC, EF6→EF Core without downtime

Universal Install (8 Platforms)

One repo, every major AI agent.

Platform	One-liner install
Claude Code	git clone https://github.com/vzubcu/dotnet-48-master-architect-skill.git && cp -r dotnet-48-master-architect-skill/.claude/skills/* ~/.claude/skills/
OpenAI Codex CLI	git clone https://github.com/vzubcu/dotnet-48-master-architect-skill.git && cp -r dotnet-48-master-architect-skill/.codex/skills/* ~/.codex/skills/
Gemini CLI	git clone https://github.com/vzubcu/dotnet-48-master-architect-skill.git && cp -r dotnet-48-master-architect-skill/.gemini/skills/* ~/.gemini/skills/
Cline	git clone https://github.com/vzubcu/dotnet-48-master-architect-skill.git && cp -r dotnet-48-master-architect-skill/.cline/skills/* ~/.cline/skills/
GitHub Copilot	git clone https://github.com/vzubcu/dotnet-48-master-architect-skill.git && cp -r dotnet-48-master-architect-skill/.github/skills/* .github/skills/ && cp dotnet-48-master-architect-skill/.github/copilot-instructions.md .github/
Cursor	curl -L https://raw.githubusercontent.com/vzubcu/dotnet-48-master-architect-skill/main/.cursorrules -o .cursorrules
Aider	curl -L https://raw.githubusercontent.com/vzubcu/dotnet-48-master-architect-skill/main/docs/aider-system-prompt.md -o docs/aider-system-prompt.md
Continue.dev	curl -L https://raw.githubusercontent.com/vzubcu/dotnet-48-master-architect-skill/main/docs/continue-system-prompt.md -o docs/continue-system-prompt.md

Cursor (project-level)

cp dotnet-48-master-architect-skill/.cursorrules ./MyProject/

Feature Deep-Dive

🧪 Testing: Not an Afterthought

Most skills say "write tests if you want." We enforce it:

Scenario	Our Approach
New feature	TDD: failing test → code → refactor. Coverage >80% line, >70% branch.
Legacy refactor	Characterization tests FIRST. Lock current behavior. Then improve.
Integration	LocalDB + TransactionScope rollback. WCF self-host. File system isolation.
Coverage gates	New code >80%, legacy post-refactor >60%, critical paths (payments, auth) 100%.

// Example: Characterization test before touching legacy
[Test]
public void CalculateDiscount_VIPCustomer_Returns20Percent()
{
    // Documents CURRENT behavior — even if it's a bug
    var result = _legacy.CalculateDiscount("VIP", 100m);
    Assert.That(result, Is.EqualTo(20m)); // Lock it. Then fix it.
}

🚀 Modernization: No Big Bang

Week 1-4:   Extract domain logic → .NET Standard 2.0 libraries
Week 5-8:   Deploy YARP gateway → route legacy + modern side-by-side
Week 9-12:  Migrate WCF → CoreWCF (stopgap) or gRPC (target)
Week 13+:   WebForms → Blazor Server page-by-page (Strangler Fig)

Every phase is deployable. Every phase has rollback. Every phase has tests.

🔒 Security: Honest About Limits

• TLS 1.2 — explicitly enforced. We never falsely claim TLS 1.3 support for .NET 4.8 runtime.
• JWT — System.IdentityModel.Tokens.Jwt (compatible version), not modern Microsoft.Identity.Web.
• OAuth2 — OWIN Katana middleware, not ASP.NET Core Identity.
• CVE tracking — References 2026 patches (CVE-2026-32177, CVE-2026-35433).

Code Snippets Included

15 production-ready snippets in snippets/:

File	What it solves
result-pattern.cs	Business logic without exceptions
guard-clauses.cs	Fail-fast validation
immutable-value-object.cs	Records without C# 9
wpf-mvvm-base.cs	INotifyPropertyChanged + RelayCommand
winforms-mvp.cs	Testable WinForms with presenter
ef6-repository.cs	Generic repository with caution notes
ef6-compiled-query.cs	Hot-path query optimization
ado-net-async.cs	Async ADO.NET pattern
wcf-security-binding.cs	BasicHttp/WSHttp/NetTcp with security
jwt-auth-filter.cs	Web API 2 JWT validation
async-composition.cs	Task.WhenAll + ConfigureAwait(false)
test-nunit-async.cs	Async test patterns
test-moq-mvp.cs	Mocking WinForms presenters
test-integration-ef6.cs	LocalDB + transaction rollback
test-legacy-coverage.cs	Characterization tests template

Audit Prompts

4 ready-to-use prompts in prompts/:

• code-review.md — Line-by-line review with [CRITICAL]/[WARNING]/[INFO]
• modernization-audit.md — Full migration roadmap with effort/risk matrix
• security-check.md — OWASP Top 10 for .NET 4.8 with CVE references
• test-generation-prompt.md — Auto-generate TDD + characterization tests

Who This Is For

• 🏦 Enterprise teams maintaining 10+ year old .NET systems
• 🏥 Healthcare devs where stability > bleeding edge
• 🏭 Industrial software with Windows-only dependencies
• 🎓 Consultants modernizing client legacy codebases
• 🤖 AI power users who want correct answers, not hallucinations

GitHub Topics (click to filter)

dotnet dotnet-framework csharp wpf winforms aspnet mvc webforms wcf ef6 legacy-modernization enterprise architecture testing tdd multi-agent orchestrator claude codex gemini copilot cline cursor skill agent-skill skillsmp mcp

License

MIT — free for commercial use, attribution appreciated.

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⭐ Star this repo if it helps your legacy codebase. SkillsMP indexes starred repos first.

🐛 Found a bug? Open an issue — we fact-check every claim against .NET 4.8 runtime.

🚀 Using it in production? We'd love to hear your story.