49+ Claude skills and 7 specialist agents that make Claude Code an expert .NET developer — running on your real code, not toy examples. EF Core, performance, architecture, testing, security, observability, DevOps — and a legacy pack for the .NET Framework code that still pays the bills. Built for modern .NET 10 / C# 14, and honest about .NET 4.8.
Curated by Stefan Đokić — TheCodeMan, Microsoft MVP.
/plugin marketplace add StefanTheCode/dotnet-ai-toolkit
/plugin install dotnet-ai-toolkit@thecodeman-ai-toolkitThat's it. Skills trigger automatically when your request matches — e.g. "optimize this EF query", "scaffold a products endpoint", "review this PR" — and you invoke an agent by asking for what it does ("audit the security of this API").
Update anytime:
/plugin marketplace update thecodeman-ai-toolkitPrefer manual install, or using these in Cowork? See INSTALL.md.
Skill — a focused capability Claude loads automatically when your request matches it. Great for "do this specific thing well" (optimize a query, generate tests, set up auth).
Agent — a specialist reviewer with its own system prompt that explores your codebase and produces a report. Great for "look at my whole repo and tell me what's wrong" (architecture review, security audit, code review).
| Category | Skills | Agents |
|---|---|---|
| Architecture | clean-architecture-scaffolder, cqrs-mediatr-setup, result-pattern-scaffolder, minimal-api-endpoint-scaffolder, ddd-aggregate-generator, crud-vs-event-sourcing, modular-monolith-generator, microservice-template-generator | dotnet-architecture-reviewer, legacy-modernization-assistant |
| EF Core / Database | ef-core-query-optimizer, ef-migration-reviewer, ef-index-advisor, sql-linq-converter, dbcontext-config-auditor, temporal-tables-setup, specification-pattern-generator, db-resiliency-setup | db-performance-auditor |
| Performance | async-await-auditor, benchmarkdotnet-setup, memory-allocation-analyzer, span-memory-refactor, caching-strategy-setup, gc-pressure-auditor, hotpath-profiler-assistant, stj-serialization-optimizer | — |
| Observability | opentelemetry-setup, serilog-logging-setup, healthchecks-setup, distributed-tracing-diagnostics, metrics-dashboard-generator, correlation-id-middleware | observability-gap-finder |
| Testing | xunit-test-generator, integration-test-setup, test-coverage-gap-finder, mutation-testing-setup, test-data-builder-generator, netarchtest-generator | — |
| Quality | — | dotnet-code-reviewer |
| Security | jwt-auth-setup, dependency-vuln-scanner, secrets-config-auditor, authorization-policy-generator | aspnetcore-security-auditor |
| Legacy (.NET Framework) | legacy-package-migrator, adonet-data-access-auditor, winforms-maintainer | legacy-modernization-assistant |
| DevOps | dockerfile-generator, cicd-pipeline-generator, nuget-dependency-analyzer, options-pattern-generator | dotnet-upgrade-agent |
Each skill and agent ships with a companion USAGE doc — what it is, when to use it, and example prompts.
Most AI tooling assumes greenfield .NET 8/10. Real ERPs run on .NET Framework 4.8, WinForms, and classic ADO.NET — and that's exactly where migrations get painful. This pack meets that code where it is:
- legacy-package-migrator —
packages.config→PackageReference→ Central Package Management (Directory.Packages.props). Kills version drift across a multi-project, multi-vendor solution and pins transitive versions once. - adonet-data-access-auditor — classic ADO.NET: SQL injection,
using/dispose leaks, reading the same column repeatedly, transactions, async. - winforms-maintainer — safe WinForms fixes (cross-thread crashes, frozen UI, control/GDI/event leaks) — maintenance, not a UI rewrite.
- legacy-modernization-assistant (agent, now legacy-aware) — triages the solution, scans for concrete blockers (System.Web, WCF, Remoting, BinaryFormatter), and hands the edits to the three skills above.
Try them on the deliberately-broken sample in examples/legacy-pack/ — see VALIDATION-REPORT.md for every planted defect and the fix each skill produces (19/19 detected).
- 🛠️ CLAUDE.md Generator — an interactive tool that generates a tailored
CLAUDE.mdfor your project. Pick your stack, architecture, conventions, and the patterns Claude should never suggest. Opentools/claude-md-generator.htmlin a browser. - 📄 CLAUDE.md template — a ready-made starting point you can drop into your repo root and fill in.
A CLAUDE.md at your repo root is what stops Claude from writing generic C# — it loads automatically at the start of every session.
This toolkit is the free, open layer. Inside the TheCodeMan AI ToolKit community I teach you, step by step, how to actually use AI in real .NET work — Claude Code workflows, building your own agents and skills, MCP servers in C#, and shipping AI features (RAG, agents) into your own apps. Live sessions and full courses, with members getting everything first.
📬 Weekly AI-in-.NET newsletter (20k+ .NET devs): thecodeman.net ·
MIT — free to use and share. A ⭐ is always appreciated.
Built by Stefan Đokić · LinkedIn · X