"Claude Code is the first AI coding tool I have used that truly understands context across files — not just the one in front of you. For .NET projects, that is a game changer."

I have been using Claude Code daily for my .NET and Azure work. This guide covers exactly how I set it up and the specific workflows that make it genuinely useful — not just a fancy autocomplete.

What is Claude Code?

Claude Code is Anthropic's CLI tool that brings Claude AI into your terminal and IDE. Unlike Copilot, which operates primarily at the line and file level, Claude Code has access to your entire project context. You can ask it to trace a bug across multiple files, explain an architecture decision, or refactor a whole module — and it understands the codebase structure to do it properly.

Installation (5 Minutes)

Prerequisites: Node.js 18+. Active Claude.ai account (Pro plan required for Claude Code).

# Install globally via npm
npm install -g @anthropic-ai/claude-code

# Verify installation
claude --version

# Start a session from your project folder
cd your-dotnet-project
claude

On first run, it opens a browser to authenticate. After that, typing claude from any project folder starts an AI session with your full codebase in context.

The CLAUDE.md File — Your Project Standing Instructions

The most powerful configuration for .NET projects is a CLAUDE.md file in your project root. Claude reads this at the start of every session — think of it as standing instructions for your AI pair programmer.

Here is the CLAUDE.md I use for my ASP.NET Core projects:

# Project Context

## Stack
- ASP.NET Core 8, C# 12
- Entity Framework Core with SQL Server
- Azure App Service + Azure Functions
- Blazor Server for frontend

## Conventions
- Use record types for DTOs
- Repository pattern with IRepository<T>
- Services registered in Program.cs via extension methods
- xUnit for tests, Moq for mocking

## Key directories
- src/Core/Interfaces/ — all service interfaces
- src/Infrastructure/ — EF Core contexts and repos
- src/Api/ — controllers and minimal API endpoints

## Avoid
- Static classes for services
- ViewBag in Blazor components

Most Useful Commands for .NET Work

  • Debugging: Paste an error and ask "diagnose this." Claude reads the surrounding code and pinpoints the root cause.
  • Adding features: "Add pagination to the GetProducts endpoint" — it reads your existing pattern and matches it consistently.
  • Writing tests: "Write xUnit tests for OrderService" — generates tests that match your existing test file patterns.
  • Code review: "Review this PR diff and tell me what problems you see" — catches things you miss after staring at code for hours.
  • Legacy code: "Explain what this EF Core migration is doing step by step" — invaluable when onboarding to an existing codebase.

Tips for Best Results

  • Be specific about scope — "in the OrdersController" is better than "in the API." Claude works best with clear file boundaries.
  • Ask it to plan before acting — "Before making any changes, explain your plan." This catches misunderstandings before code is written.
  • Use it for architecture questions — "Should I use a domain event or a direct service call here?" gives you senior-engineer-level analysis grounded in your actual codebase.