What is Claude Code?
Claude Code is Anthropic's AI coding assistant that runs directly in your terminal. It operates agentically: it reads your project files on demand, proposes changes, and asks for approval before editing anything. You talk to it in natural language — like a teammate.
Beyond the terminal, Claude Code is also available in VS Code, JetBrains, as a desktop app, on the web at claude.ai/code, and in CI/CD via GitHub Actions and GitLab.
Installation
The official docs recommend the native installer, which auto-updates in the background:
macOS / Linux / WSL:
curl -fsSL https://claude.ai/install.sh | bash
Windows PowerShell:
irm https://claude.ai/install.ps1 | iex
On Windows, Git for Windows must be installed first.
Alternative methods (no auto-update — you must upgrade manually):
- Homebrew:
brew install --cask claude-code - WinGet:
winget install Anthropic.ClaudeCode - VS Code: extension
anthropic.claude-code
First-run login
Run claude in your terminal and you'll see the login prompt. Accepted accounts:
- Claude Pro, Max, Team or Enterprise (recommended)
- Claude Console (API access with pre-paid credits — a "Claude Code" workspace is created automatically for cost tracking)
- Enterprise providers: Amazon Bedrock, Google Vertex AI, Microsoft Foundry
Use /login inside a session to switch accounts. Credentials are stored locally after first login.
First flow
cd /path/to/your/project
claude
You land on a welcome screen with session info, recent conversations and updates. Type /help for commands or /resume to continue a previous conversation.
6 practical flows from the official Quick Start
1. Understand the codebase
what does this project do?
what technologies does this project use?
explain the folder structure
where is the main entry point?
2. Make a code change
add a hello world function to the main file
Claude finds the file, shows the diff, asks for approval, then edits.
3. Git operations
what files have I changed?
commit my changes with a descriptive message
create a new branch called feature/quickstart
help me resolve merge conflicts
4. Fix a bug
there's a bug where users can submit empty forms - fix it
5. Add a feature with validation
add input validation to the user registration form
6. Refactor, write tests, update docs, review code
refactor the authentication module to use async/await instead of callbacks
write unit tests for the calculator functions
update the README with installation instructions
review my changes and suggest improvements
Essential commands
| Command | What it does |
|---|---|
| claude | Start interactive mode |
| claude "task" | Run a one-time task |
| claude -p "query" | Run one-off query, then exit |
| claude -c | Continue most recent conversation in current directory |
| claude -r | Resume a previous conversation |
| /clear | Clear conversation history |
| /help | Show available commands |
| exit or Ctrl+D | Exit Claude Code |
Useful shortcuts: ? shows all keyboard shortcuts, Tab for completion, up arrow for history, / to browse all commands and skills.
Next steps
After the quick start, explore:
- How Claude Code works — the agentic loop and built-in tools
- Best practices — effective prompting and project setup
- Common workflows — step-by-step guides
- Extending Claude Code —
CLAUDE.md, skills, hooks and MCP
Community: Anthropic Discord.
Official docs: code.claude.com/docs/en/quickstart.
