Claude Code CLI: Complete Commands Reference with Examples

Claude Code's command-line interface is where the magic happens. Whether you're navigating projects, customizing behavior, or building complex workflows, understanding the CLI is essential. This reference covers every command, flag, and configuration option available.

Getting Started

Installation

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

# Or use npx for one-time usage
npx @anthropic-ai/claude-code

First Run

# Start Claude Code in current directory
claude

# Start in a specific directory
claude /path/to/project

# Start with a specific prompt
claude "Explain the architecture of this project"

Authentication

# Login to your Anthropic account
claude login

# Check authentication status
claude auth status

# Logout
claude logout

Core Commands

Starting Sessions

Examples:

# Start fresh session
claude

# Start with context
claude "Review the authentication flow in this project"

# Resume where you left off
claude --resume

# Open specific project
claude ~/projects/my-app

Session Management

Examples:

> /save feature-implementation
Session saved as "feature-implementation"

> /load feature-implementation
Session loaded. 24 messages restored.

> /sessions
Available sessions:
- feature-implementation (2 hours ago)
- bug-investigation (yesterday)
- refactoring-session (3 days ago)

> /history
Showing last 10 messages...

Built-in Slash Commands

File Operations

Examples:

> /read src/components/Button.tsx
Reading Button.tsx...
[File contents displayed]

> /find "*.test.ts"
Found 47 test files:
- src/components/__tests__/Button.test.ts
- src/hooks/__tests__/useAuth.test.ts
...

> /grep "TODO:"
Found 12 TODO comments:
- src/api/users.ts:45 - TODO: Add validation
- src/utils/format.ts:23 - TODO: Handle edge case
...

> /tree src/components
src/components/
├── Button/
│   ├── Button.tsx
│   ├── Button.test.tsx
│   └── index.ts
├── Card/
│   ├── Card.tsx
│   └── index.ts
└── index.ts

Git Operations

Examples:

> /git status
On branch feature/auth
Changes not staged for commit:
  modified: src/auth/login.ts
  modified: src/auth/register.ts

> /git diff src/auth/login.ts
Showing diff for login.ts...
[Diff output]

> /git log -5
Recent commits:
abc1234 - Add password validation (2 hours ago)
def5678 - Fix login redirect (yesterday)
...

Navigation

Examples:

> /pwd
/Users/dev/projects/my-app

> /cd src/components
Changed to /Users/dev/projects/my-app/src/components

> /ls
Button/
Card/
Form/
Modal/
index.ts

Help and Information

Examples:

> /help
Available commands:
  /clear      Clear conversation
  /reset      Reset session
  /save       Save session
  /load       Load session
  ...

> /help commit
/commit - Create a git commit

Usage: /commit [message]

Creates a conventional commit based on staged changes.
If no message provided, generates one automatically.

> /tools
Available tools:
- Bash: Execute shell commands
- Read: Read file contents
- Edit: Edit files
- Grep: Search file contents
- Glob: Find files by pattern

MCP Servers:
- postgres: Database operations
- github: GitHub API access

CLI Flags and Options

Startup Flags

Examples:

# Use specific model
claude --model claude-3-opus

# Start fresh without project context
claude --no-context

# Show version
claude --version
Claude Code v1.0.45

Output Flags

Examples:

# One-shot query with output
claude -p "What's in package.json?" > analysis.txt

# JSON output for scripting
claude --json "List all dependencies" | jq '.dependencies'

# Verbose mode for debugging
claude --verbose "Debug this error"

Configuration Flags

Examples:

# Use custom config
claude --config ./custom-settings.json

# Override CLAUDE.md
claude --claude-md ./docs/AI_CONTEXT.md

# Disable MCP for testing
claude --no-mcp

# Pre-approve specific permissions
claude --allow bash --allow write

Configuration

Configuration Files

Claude Code reads configuration from multiple sources (in order of precedence):

1. CLI flags
2. Environment variables
3. Project config (.claude/settings.json)
4. User config (~/.claude/settings.json)
5. Default values

Settings File Structure

{
  "model": "claude-3-5-sonnet-20241022",
  "maxTokens": 8192,
  "temperature": 0.7,
  "theme": "dark",
  "editor": "vscode",
  "shell": "/bin/zsh",
  "autoSave": true,
  "historyLength": 100,
  "permissions": {
    "bash": "ask",
    "write": "ask",
    "network": "deny"
  },
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"]
    }
  }
}

Key Configuration Options

Model Settings:

Interface Settings:

Permission Settings:

Environment Variables

# API Key (required)
export ANTHROPIC_API_KEY="sk-ant-..."

# Optional overrides
export CLAUDE_MODEL="claude-3-opus"
export CLAUDE_MAX_TOKENS="4096"
export CLAUDE_CONFIG="~/.claude/custom-settings.json"

# Debug mode
export CLAUDE_DEBUG="true"

Common Workflows

Code Review Workflow

# Start Claude Code
claude

# Review changes
> Review the changes in this PR for security issues and best practices.
> Focus on the authentication module.

# Get specific file review
> /read src/auth/middleware.ts
> What security vulnerabilities exist in this middleware?

# Commit the fixes
> /commit "Fix authentication vulnerabilities"

Bug Investigation Workflow

# Start with error context
claude "I'm seeing this error: 'Cannot read property of undefined'"

# Search for related code
> /grep "property of undefined"

# Investigate specific file
> /read src/utils/dataProcessor.ts

# Find all usages
> /find "**/dataProcessor*"

# Review related tests
> /read src/utils/__tests__/dataProcessor.test.ts

# Implement fix
> Fix the null check issue in dataProcessor.ts

Refactoring Workflow

# Start session
claude

# Understand current structure
> /tree src/components

# Analyze component
> /read src/components/UserProfile.tsx
> This component is too large. How should I split it?

# Plan the refactoring
> Create a refactoring plan for UserProfile.tsx

# Execute refactoring
> Implement step 1 of the refactoring plan

# Verify tests still pass
> Run the tests for UserProfile

Documentation Workflow

# Generate docs
claude "Generate API documentation for the auth module"

# Review generated docs
> /read docs/api/auth.md

# Update README
> Update README.md with setup instructions for the new auth system

# Create examples
> Add code examples for common authentication flows

Power User Tips

Command Chaining

Execute multiple operations in sequence:

# Multiple prompts in one session
claude << 'EOF'
First, review the authentication code.
Then, identify any security issues.
Finally, suggest fixes with code examples.
EOF

Scripting with Claude Code

Use Claude Code in shell scripts:

#!/bin/bash

# Generate commit message
MESSAGE=$(claude -p "Generate a commit message for these changes: $(git diff --staged)")
git commit -m "$MESSAGE"

# Analyze code changes
claude -p "Review this diff for issues: $(git diff HEAD~1)" > review.md

# Generate documentation
for file in src/api/*.ts; do
  claude -p "Generate JSDoc for: $(cat $file)" > "docs/$(basename $file .ts).md"
done

Aliases for Common Operations

Add to your shell profile:

# ~/.zshrc or ~/.bashrc

# Quick Claude commands
alias c="claude"
alias cr="claude --resume"
alias cc="claude --continue"

# Code review
alias review="claude 'Review the staged changes for issues'"

# Quick documentation
alias doc="claude 'Generate documentation for this file'"

# Explain code
explain() {
  claude -p "Explain this code: $(cat $1)"
}

# Fix linting errors
alias fixlint="claude 'Fix all linting errors in the project'"

Session Templates

Create reusable session starters:

# ~/.claude/templates/code-review.md
I'm doing a code review session. For each file I show you:
1. Check for security vulnerabilities
2. Identify performance issues
3. Suggest improvements
4. Note any anti-patterns

Be thorough but concise.

Use with:

claude "$(cat ~/.claude/templates/code-review.md)"

Advanced Grep Patterns

# Find all TODO comments with context
> /grep -C 3 "TODO:|FIXME:|HACK:"

# Find all exported functions
> /grep "^export (async )?function"

# Find all React components
> /grep "^export (default )?(function|const) [A-Z]"

# Find all API endpoints
> /grep "app\.(get|post|put|delete)\("

Custom File Patterns

# Find all config files
> /find "*.config.{js,ts,json}"

# Find all test files
> /find "**/*.{test,spec}.{ts,tsx}"

# Find all markdown docs
> /find "**/*.md" --ignore "node_modules"

# Find large files
> /find "**/*.ts" --size ">100k"

Troubleshooting

Common Issues

Claude Code won't start:

# Check installation
which claude

# Reinstall
npm uninstall -g @anthropic-ai/claude-code
npm install -g @anthropic-ai/claude-code

# Check API key
echo $ANTHROPIC_API_KEY

Session not loading:

# Clear cache
rm -rf ~/.claude/cache

# Reset configuration
mv ~/.claude/settings.json ~/.claude/settings.json.backup

# Check permissions
ls -la ~/.claude/

MCP servers not working:

# Check MCP configuration
> /config

# Test server manually
npx @modelcontextprotocol/server-postgres

# Check logs
> /tools

Slow performance:

# Reduce history length
# In settings.json:
{
  "historyLength": 50
}

# Clear old sessions
rm ~/.claude/sessions/*.json

# Use smaller model
claude --model claude-3-haiku

Debug Mode

Enable debug output:

CLAUDE_DEBUG=true claude

# Or in session
> /debug on
Debug mode enabled. Showing tool calls and API requests.

Getting Help

# In-app help
> /help

# Command-specific help
> /help <command>

# Online documentation
claude docs

# Report issues
claude feedback

Quick Reference Card

Essential Commands

Essential Flags

Essential Shortcuts

Conclusion

The Claude Code CLI is your gateway to AI-assisted development. Master these commands, and you'll find yourself navigating projects, debugging issues, and writing code faster than ever.

Start with the basics: /help, /read, /find. Then gradually incorporate more advanced workflows. Before long, Claude Code becomes an extension of your development environment—always ready, always helpful.

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Ready to extend Claude Code further? Check out our Plugin Development Guide to build your own integrations.