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Claude Code Cheat Sheet

Quick reference guide for Claude Code CLI commands, shortcuts, and workflows.

Installation & Quick Start

npm install -g @anthropic-ai/claude-code
claude                    # Launch interactive REPL
claude --version         # Check version
claude update            # Update to latest

Essential Commands

Navigation & Session

Command Description
/help Display available commands
/exit Terminate REPL
/clear Reset conversation history
/config Access configuration panel
/doctor Verify installation status
/cos Display session costs and duration
/compact Summarize conversation to save context

Keyboard Shortcuts

Shortcut Action
Ctrl+C Cancel current operation
Ctrl+D Exit application
Tab Auto-complete
Up/Down Navigate command history

CLI Modes

Interactive Mode

claude                           # Start REPL
claude "explain this codebase"   # REPL with initial prompt

claude -p "explain this function"           # Single query, output to stdout
cat logs.txt | claude -p "explain errors"   # Pipe content for analysis

Session Management

claude -c                        # Continue last conversation
claude --continue                # Same as -c
claude -r "session-id" "query"   # Resume specific session by ID

Model Selection

claude --model sonnet                        # Use Sonnet (faster, cheaper)
claude --model opus                          # Use Opus (most capable)
claude --model claude-sonnet-4-20250514      # Specific version

Directory & File Operations

claude --add-dir ../apps ../lib              # Add multiple working directories

Output Formats

claude -p "query" --output-format text         # Plain text (default)
claude -p "query" --output-format json         # JSON output for scripting
claude -p "query" --output-format stream-json  # Streaming JSON

Tool Permissions

Allow Specific Tools

claude --allowedTools "Bash(git:*)" "Write" "Read"
claude --allowedTools "Bash(git log:*)" "Bash(git status:*)"

Disallow Dangerous Tools

claude --disallowedTools "Bash(rm:*)" "Bash(sudo:*)"

Skip All Permission Prompts (Use with Caution)

claude --dangerously-skip-permissions

Combined Example

claude --allowedTools "Bash(git:*)" "Write" "Read" \
       --disallowedTools "Bash(rm:*)" "Bash(sudo:*)"

Session Control

claude -p --max-turns 3 "focused query"    # Limit iterations
claude --verbose                           # Enable detailed logging

Advanced Usage

Piping & Automation

# Analyze git history
git log --oneline -10 | claude -p "summarize these commits"

# Error analysis
cat error.log | claude -p "find the root cause"

# Code review
git diff HEAD~1 | claude -p "review for security issues" > review.md

# Generate changelog
git log --oneline -20 | claude -p "create changelog" > CHANGELOG.md

Batch Processing

# Analyze multiple files
find . -name "*.js" -exec claude -p "analyze: {}" \; > report.txt

# Generate documentation
for file in src/*.py; do
  claude -p "generate docstring for $file" >> docs.md
done

JSON Output for Scripts

# Save analysis as JSON
claude -p "analyze codebase" --output-format json > analysis.json

# Parse with jq
SESSION_ID=$(claude -p "task" --output-format json | jq -r '.session_id')

Custom Slash Commands

Create custom commands in .claude/commands/ directory:

mkdir -p .claude/commands

Example: .claude/commands/review.md

Review this code for:
1. Security vulnerabilities
2. Performance issues
3. Best practice violations

Use with: /project:review

MCP (Model Context Protocol)

claude --mcp                    # Configure MCP servers
/mcp                            # Access MCP in REPL

IDE Integration

/ide vscode                     # Configure VS Code integration
/ide configure                  # General IDE setup

Performance Optimization

Best Practices

  1. Clear between tasks: Use /clear to reset context
  2. Limit turns: Use --max-turns for focused queries
  3. Compact conversations: Use /compact for long sessions
  4. Check costs: Use /cos to monitor usage

Examples

# Quick, focused analysis
claude -p --max-turns 1 "quick code review"

# Compact long conversation
/compact "keep architecture decisions only"

# Parallel processing
claude -p "task 1" & claude -p "task 2" & wait

Troubleshooting

Installation Issues

claude --version                           # Check installation
claude /doctor                             # Run diagnostics
npm reinstall -g @anthropic-ai/claude-code # Reinstall

Performance Issues

/clear                                     # Reset conversation
/compact "keep essentials"                 # Reduce context
claude -p --max-turns 3 "query"            # Limit iterations

Permission Issues

claude --allowedTools "Bash(git:*)"        # Grant specific permissions
claude --disallowedTools "Bash(rm:*)"      # Restrict dangerous commands

Common Workflows

Code Review Workflow

# Security review
git diff main | claude -p "review for security vulnerabilities"

# Performance review
git diff main | claude -p "identify performance issues"

# Style review
git diff main | claude -p "check code style and best practices"

Documentation Workflow

# Generate README
claude -p "generate README for this project" > README.md

# API documentation
claude -p "document all public functions" > API.md

# Changelog
git log --oneline v1.0..HEAD | claude -p "create changelog" > CHANGELOG.md

Debugging Workflow

# Analyze error logs
cat error.log | claude -p "identify root cause and suggest fixes"

# Debug specific file
claude -p "find bugs in src/auth.js"

# Stack trace analysis
cat stacktrace.txt | claude -p "explain this error and how to fix it"

Security Best Practices

  1. Never use --dangerously-skip-permissions in production
  2. Always restrict dangerous commands with --disallowedTools
  3. Keep updated: Run claude update regularly
  4. Audit usage: Check /cos for unexpected activity
  5. Use specific permissions: Prefer Bash(git log:*) over Bash(git:*)

Quick Reference Card

Task Command
Start REPL claude
Quick query claude -p "query"
Continue session claude -c
Resume by ID claude -r "id" "query"
Check costs /cos
Clear history /clear
Compact context /compact
Use Opus model claude --model opus
JSON output --output-format json
Limit turns --max-turns N
Add directories --add-dir path1 path2
Allow tools --allowedTools "Tool"
Block tools --disallowedTools "Tool"

Resources