Can you use Claude Code with multiple codebases simultaneously?

Yes, open a separate terminal window for each codebase. Each Claude Code instance runs independently with its own context and session.

Does Claude Code work on Windows?

Yes, Claude Code works smoothly on Windows via WSL2 (Windows Subsystem for Linux). Install WSL2, then install Claude Code within the Linux environment. You can edit files in Visual Studio Code while Claude Code runs in the WSL terminal.

Can you use Claude Code on a VPS/remote server?

Yes, Claude Code can be installed and run on VPS with proper security setup. This allows you to work on projects with more computational resources or maintain persistent sessions. Ensure proper firewall configuration and secure access methods.

How do you stop Claude Code from asking for permissions every time?

Start Claude Code with 'claude --dangerously-skip-permissions' OR configure allowedTools in ~/.claude.json. See Configuration for details.

How should you structure your CLAUDE.md file?

Break it into clear sections using markdown headers to organize different workflows. Include specific examples and step-by-step procedures rather than general instructions. Tell Claude exactly which files it should read or avoid. Since Claude follows CLAUDE.md more strictly than prompts, be thorough and specific.

How do I configure an MCP server with Claude Code?

Configure MCP servers in ~/.claude.json or ~/.claude/mcp_servers.json to connect external tools. See Configuration for setup details.

How do you add multiple working directories in Claude Code?

Use the --add-dir CLI argument to access multiple directories beyond your current working directory. For example: claude --add-dir /path/to/other/project or claude --add-dir ../backend-api to work across multiple repositories simultaneously. This enables cross-project collaboration while maintaining context.

How do you activate Plan Mode in Claude Code?

Press Shift+Tab twice in Claude Code version 1.0.16+

What does Auto-Compact mean in Claude Code?

When context window approaches limit, Claude Code automatically summarizes the conversation to free up space and continue working. You can also manually compact using /compact command.

What is the Task tool in Claude Code and when should you use it?

The Task tool launches parallel sub-agents. Each Task creates a sub-agent, indicated within the Claude Code UI by a flashing bubble that turns green when complete.

How do you enable terminal bell notifications in Claude Code?

Enable terminal bell notifications with 'claude config set --global preferredNotifChannel terminal_bell' to get audio alerts when Claude completes tasks. Test with 'echo -e "\a"' to verify your terminal supports bell sounds. No restart required after configuration.

Can I use Claude Code with the Pro subscription?

Yes, Claude Code works with Claude Pro, but you're limited to the Claude 4 Sonnet model and have lower usage limits compared to Claude Max.

What's the difference between Claude Max 5X and regular Pro for Claude Code?

Claude Max 5X provides 5x higher usage limits and access to Claude 4 Opus in Claude Code. Pro plan can only use Sonnet and Haiku in Claude Code. With Max using Sonnet you rarely hit limits; with Opus you hit limits after ~2 hours.

Should you use many small files or few large files with Claude Code?

Use many small files organized by logical boundaries. This reduces context window usage since Claude only loads relevant files, improves code comprehension, and prevents token waste from loading massive files for small changes.

Where can I find additional tools, extensions, and community projects for Claude Code?

Check out Awesome Claude Code (https://github.com/hesreallyhim/awesome-claude-code) for a curated collection of community tools, extensions, tips, and additional resources.

What is CLAUDE.md and why is it important?

CLAUDE.md is a project-specific configuration file that gives Claude Code detailed instructions about your project. It's crucial because Claude follows CLAUDE.md instructions more strictly than regular prompts, making it essential for consistent behavior and optimal results.

How do I install Claude Code?

Install Claude Code using npm: 'npm install -g @anthropic-ai/claude-code'. You'll need Node.js 18.0+ and either an Anthropic API key or Claude Max subscription. Configure with 'claude config' after installation.

Which Claude model should I use with Claude Code?

For most development work, use Claude 4 Sonnet for balanced performance and speed. Use Claude 4 Opus for complex tasks requiring maximum capability. Claude 3.5 Haiku is cost-effective but has limitations for serious development work.

What are the system requirements for Claude Code?

Claude Code requires Node.js 18.0+, 4GB RAM minimum (16GB recommended), 500MB disk space, and internet connectivity. Supports macOS 10.15+, Windows 10+, and Linux (Ubuntu 18.04+, CentOS 7+).

How do I troubleshoot Claude Code installation issues?

Common solutions: 1) Verify Node.js 18.0+ is installed, 2) Check API key setup with 'claude config', 3) Ensure internet connectivity, 4) Try reinstalling with 'npm install -g @anthropic-ai/claude-code --force', 5) For permission issues on macOS/Linux, use sudo or fix npm permissions.

How do I check my Claude Code usage to avoid unexpected API costs?

API users can check usage in the Anthropic Console (https://console.anthropic.com). Subscription users should use the CC Usage tool (https://github.com/ryoppippi/ccusage): install with 'npm install -g ccusage', then run 'ccusage' for detailed token and cost breakdowns.

Is Claude Code slower on WSL compared to native Linux?

Yes, Claude Code typically runs more efficiently on native Linux due to direct system access and reduced overhead. WSL2 introduces virtualization layers that can impact performance, especially for file operations and process spawning.

Can Claude Code analyze images and screenshots from my computer?

Yes, Claude Code can analyze images from your computer. Reference image file paths in your conversation or paste images directly into the terminal. Useful for debugging UI issues, analyzing screenshots, and visual documentation.

How do auto-compact, /compact, and /clear work in Claude Code?

Claude Code has three context management options: 1) Auto-compact automatically summarizes conversations when approaching context limits, 2) '/compact [instructions]' lets you manually summarize with specific preservation instructions (e.g., '/compact only keep the names of the websites we reviewed'), and 3) '/clear' starts a fresh conversation. You can disable auto-compact in '/config' for manual control.

Can I use Visual Studio Code with Claude Code on Windows WSL?

Yes, you can edit files in Visual Studio Code while Claude Code runs in the WSL terminal. This provides the best of both worlds: a familiar editor interface with Claude Code's powerful terminal capabilities. VS Code integrates seamlessly with WSL2. To install the Claude Code VS Code extension: 1) Open VS Code, 2) Open the integrated terminal, 3) Run 'claude' - the extension will auto-install, 4) Use '/ide' command in any external terminal to connect to the IDE.

How do I switch between different Claude models in Claude Code?

Use the command line flag '--model' when starting Claude Code. For example: 'claude --model claude-sonnet-4-20250514' for Sonnet 4 or 'claude --model claude-opus-4-20250514' for Opus 4. You can also use '/model' command within an active session to switch models.

How do I set up terminal bell notifications on Windows WSL?

For Windows WSL users, if the standard terminal bell doesn't work, Claude Code can run these PowerShell commands for audio notifications: Default beep: 'powershell.exe -c "[System.Media.SystemSounds]::Beep.Play()"' or Question sound: 'powershell.exe -c "[System.Media.SystemSounds]::Question.Play()"'. Enable notifications with: 'claude config set --global preferredNotifChannel terminal_bell'.

How do sub-agents work in Claude Code and when should I use them?

Sub-agents are parallel task executors that run independently with their own context window. They're useful for tasks requiring multiple file operations or research phases. For example, if Claude needs to write several different files on different topics, each sub-agent can research and write independently. Sub-agents perform tasks significantly faster than the interactive Claude instance.

Do sub-agents consume the main agent's context window?

Sub-agents have their own separate context windows and are provided with the task and light context. Only the results they return consume space in the main agent's context window, not their internal processing. This makes them efficient for complex multi-step tasks.

Can I use both API keys and subscription plans with Claude Code?

Yes, Claude Code supports both Anthropic API keys and Claude subscription plans (Pro and Max). Configure your preferred authentication method with 'claude config'. Subscription users get different usage limits and model access compared to API users.

Why is Claude Code showing 503 error? Is my Claude Code broken?

No, a 503 error indicates server issues, not problems with your Claude Code installation. This means Anthropic's servers are temporarily busy or under maintenance. The error usually resolves in 2-5 minutes automatically. Check https://status.anthropic.com/ for official server status or r/ClaudeAI for community reports.

Is Claude Code down for everyone right now? How do I check if Claude Code is just me?

To check if Claude Code is down for everyone: visit https://status.anthropic.com/ for official status and r/ClaudeAI for user reports. Test other websites to verify your internet connection. Widespread outages show multiple Reddit reports within minutes, while individual issues usually resolve in 1-2 minutes.

Why am I getting Claude Code API errors? Is there a Claude Code API outage?

Claude Code API errors are usually temporary connectivity issues, not API outages. Common causes include connection timeouts, server overload (503 errors), or rate limiting. Check https://status.anthropic.com/ for API status and restart Claude Code. True API outages affecting all users are rare and announced on the status page.

What does Claude Code internal server error mean? How do I fix it?

Claude Code internal server errors are temporary backend processing issues on Anthropic's servers, not problems with your setup. These usually resolve automatically within 1-3 minutes. Check https://status.anthropic.com/ for backend issues and avoid reinstalling Claude Code as it won't help with server-side errors.

Claude Code is Anthropic's official CLI for AI-assisted coding. It's a terminal-based development tool with file management, code analysis, multi-model support, and MCP server integration that works directly in your development environment.

How do I get started with Claude Code?

Install via npm, navigate to your project, run 'claude', then ask 'explain what this repo is about' to get immediate project-specific guidance. The key is understanding the conversation-based workflow that makes it different from traditional coding tools.

What can Claude Code do?

Claude Code handles code analysis, feature development, refactoring, debugging, testing, documentation, and works with virtually any programming language and framework. It can read files directly, make coordinated changes across multiple files, and maintain context throughout your session.

Claude Code is free to install but requires a Claude subscription ($20-200/month) or Anthropic API credits for usage. Claude Pro costs $20/month, Claude Max costs $200/month with higher limits and Opus access, while API pricing is pay-per-use.

How do I write better prompts for Claude Code?

Be specific about what you want, provide context about your project and constraints, set clear scope, and leverage CLAUDE.md for persistent context. Instructions in CLAUDE.md are followed more strictly than prompts, so document your project structure and coding standards there.

How do I use Claude Code for debugging?

Claude Code excels at error analysis, stack trace interpretation, and logic tracing. Provide full error messages and context for best results. It can trace bugs across multiple files, recognize patterns, and identify edge cases that cause failures.

How do I use Claude Code for code review?

Claude Code provides comprehensive code reviews covering quality, security, performance, and best practices. It can analyze entire files or specific functions, check for patterns, and provide detailed improvement suggestions with context awareness.

What programming languages work best with Claude Code?

JavaScript/TypeScript, Python, and Java have excellent support. Claude Code works with virtually any language but excels with popular frameworks and well-structured projects. Python shows the strongest community satisfaction based on user feedback.

What is the difference between Claude API and subscription?

API offers pay-per-use pricing with detailed usage tracking, while subscriptions provide fixed monthly costs ($20 Pro, $200 Max) with predictable billing. API users get dedicated limits and detailed cost breakdowns, while subscription users have shared limits with web usage.

Does Claude Code store my data?

Claude Code sends your code to Anthropic's servers for processing. Consumer products retain data for 30 days standard, with longer retention for flagged content. Enterprise API customers may be eligible for Zero Data Retention agreements. Consider data sensitivity when working with proprietary code.

Why is Claude Code not working?

Common issues include authentication problems, network connectivity, installation issues, or usage limits. Start with checking authentication and service status at https://status.anthropic.com/. Most issues resolve with basic troubleshooting like restarting Claude Code or checking API keys.

How do I install Claude Code on Windows?

Claude Code works on Windows via WSL2. Install WSL2, then install Node.js 18.0+ and Claude Code within the Linux environment. You can edit files in Visual Studio Code while Claude Code runs in the WSL terminal for seamless integration.

How do I use Claude Code with VS Code?

Open VS Code, open the integrated terminal, and run 'claude'. The VS Code extension auto-installs when it detects Claude Code running. This provides the best of both worlds: familiar VS Code interface with Claude Code's powerful terminal capabilities.

How do I switch between Claude models?

Use '--model' flag when starting Claude Code or '/model' command during a session. Use Sonnet 4 for most daily work, Opus 4 for complex reasoning, and Haiku 3.5 for simple tasks. Example: 'claude --model claude-sonnet-4-20250514'.

What is Claude Code auto-compact?

Auto-compact automatically summarizes conversations when approaching context window limits. You can also manually compact with '/compact' command or use '/clear' for fresh conversations. Manual compacting at strategic times provides better control than automatic triggering.

What is the difference between Claude 3.5 and Claude 4?

Claude 4 models (Opus and Sonnet) offer superior performance, better reasoning, and faster responses compared to Claude 3.5. Claude 4 Sonnet provides the best balance for daily development, while Claude 4 Opus excels at complex analysis. Claude 3.5 Sonnet remains cost-effective for budget-conscious workflows.

How much does Claude AI cost?

Claude AI pricing: Pro plan costs $20/month with Sonnet 4 access, Max plan costs $200/month with all models including Opus and 5x higher limits. API pricing is pay-per-use: Opus $15/$75 per million tokens, Sonnet $3/$15 per million tokens.

Claude 3.5 vs Claude 4: Complete Model Comparison Guide

Compare Claude 3.5 Sonnet vs Claude 4 Opus and Sonnet models for developers. This comprehensive guide covers performance, speed, cost analysis, and expert recommendations to help you choose the right Claude model for your development workflow.

Claude Model Overview: 3.5 vs 4 Comparison

Claude 3.5 and Claude 4 models offer different capabilities optimized for various use cases. For Claude Code development, comparing Claude 3.5 Sonnet vs Claude 4 Opus and Sonnet helps you choose the right model based on performance, cost, and development experience.

Model	Performance	Speed	Cost	Best For
Claude 4 Opus	Highest	Slower	Most Expensive	Complex reasoning, architecture decisions
Claude 4 Sonnet	High	Fast	Moderate	Daily development, balanced workflow
Claude 3.5 Sonnet	Good	Fast	Lower	Most development tasks, good balance
Claude 3.5 Haiku	Basic	Fastest	Cheapest	Simple tasks, learning Claude Code

Detailed Model Comparison

Claude 4 Opus - Maximum Capability

Best for: Complex architectural decisions, large codebase analysis, advanced debugging

Strengths:

Superior reasoning - Excels at complex multi-step problems
Deep code analysis - Understands intricate dependencies and patterns
Architectural insight - Best for system design and refactoring decisions
Advanced debugging - Traces complex issues across multiple files
Code review excellence - Catches subtle bugs and security issues

Limitations:

Slower responses - Takes more time for complex analysis
Higher cost - Most expensive option for API users
Usage limits - Max subscribers hit limits after ~2 hours of intensive use

Claude Code Use Cases:

# Start Claude Code with Opus for complex tasks
claude --model claude-opus-4-20250514

# Best for:
- Large-scale refactoring projects
- Complex architectural decisions  
- Advanced debugging of multi-file issues
- Comprehensive code reviews
- Database schema optimization

Claude 4 Sonnet - Balanced Excellence (Recommended)

Best for: Daily development workflow, most coding tasks, balanced performance

Strengths:

Optimal balance - Great performance without Opus slowness
Fast responses - Quick enough for interactive development
Comprehensive capabilities - Handles most development tasks excellently
Cost effective - Best value for performance ratio
Reliable availability - Rarely hit usage limits with Max subscription

Claude Code Use Cases:

# Default recommended model
claude --model claude-sonnet-4-20250514

# Perfect for:
- Feature development and implementation
- Bug fixing and troubleshooting
- Code refactoring and optimization
- Writing tests and documentation
- API integration and database work

Why Sonnet 4 is Recommended:

90% of Opus capability at 2x the speed
Rarely hits usage limits even with heavy development
Ideal for pair programming workflow with Claude Code
Best overall developer experience

Claude 3.5 Sonnet - Solid Performance

Best for: Most development tasks, budget-conscious workflows, learning

Strengths:

Good capabilities - Handles most coding tasks well
Fast responses - Quick turnaround for development
Lower cost - More economical than Claude 4 models
Wide availability - Accessible across subscription tiers

Limitations:

Less sophisticated reasoning - May miss complex patterns
Limited context understanding - Not as good with large codebases
Fewer advanced features - Missing some capabilities of newer models

Claude Code Use Cases:

# Cost-effective option
claude --model claude-3-5-sonnet-20241022

# Good for:
- Single-file editing and improvements
- Basic feature implementation
- Learning Claude Code workflows
- Simple debugging and fixes
- Documentation writing

Claude 3.5 Haiku - Fast and Economical

Best for: Simple tasks, learning Claude Code, budget projects

Strengths:

Fastest responses - Nearly instant for simple tasks
Most economical - Lowest cost option
Good for basics - Handles simple coding tasks well

Significant Limitations for Development:

Reduced reasoning - Struggles with complex logic
Limited context - Poor with large files or multi-file projects
Basic analysis - Misses sophisticated patterns and issues
Simple refactoring only - Not suitable for complex restructuring

Claude Code Use Cases:

# Budget/learning option only
claude --model claude-3-5-haiku-20241022

# Limited to:
- Simple syntax fixes
- Basic file edits
- Learning Claude Code commands
- Quick code explanations
- Small script generation

Model Selection Guide

For Different Development Scenarios

Large Projects & Architecture:

Use: Claude 4 Opus
Why: Best at understanding complex systems and dependencies

Daily Development Workflow:

Use: Claude 4 Sonnet
Why: Perfect balance of capability, speed, and availability

Learning & Exploration:

Use: Claude 3.5 Sonnet
Why: Good capabilities at lower cost for experimentation

Simple Tasks & Budget Work:

Use: Claude 3.5 Haiku
Why: Fast and cheap for basic operations

Performance Comparison

Code Analysis Speed:

Haiku - Instant but shallow
Sonnet 3.5 - Fast with good depth
Sonnet 4 - Fast with excellent depth
Opus 4 - Slower but deepest analysis

Reasoning Quality:

Opus 4 - Superior complex reasoning
Sonnet 4 - Excellent reasoning for most tasks
Sonnet 3.5 - Good reasoning, some limitations
Haiku - Basic reasoning only

Cost Efficiency:

Haiku - Cheapest per task
Sonnet 3.5 - Good value for capability
Sonnet 4 - Best performance per dollar
Opus 4 - Premium pricing for premium capability

Switching Models in Claude Code

Command Line Options

Start with specific model:

# Recommended for most work
claude --model claude-sonnet-4-20250514

# For complex analysis
claude --model claude-opus-4-20250514

# For budget-conscious development  
claude --model claude-3-5-sonnet-20241022

# For simple tasks only
claude --model claude-3-5-haiku-20241022

Switch models during session:

# Change to Opus for complex task
/model claude-opus-4-20250514

# Switch back to Sonnet for regular work
/model claude-sonnet-4-20250514

Environment Variables

Set default model:

# In your shell profile (.bashrc, .zshrc)
export ANTHROPIC_MODEL="claude-sonnet-4-20250514"

Cost Considerations

Subscription vs API Pricing

Claude Max Subscription ($200/month):

All models included - Opus, Sonnet 4, Sonnet 3.5, Haiku
Higher usage limits - Rarely hit limits with Sonnet 4
Opus access - Available but with limited daily usage
Best for: Regular Claude Code users

Claude Pro Subscription ($20/month):

Limited models - Sonnet 4 and Haiku only (no Opus)
Lower usage limits - May hit limits with heavy development
Budget option - Good for occasional Claude Code use

API Pricing (Pay-per-use):

Precise cost control - Pay only for what you use
All models available - Including latest releases
Variable costs - Can be expensive with heavy usage
Best for: Occasional users or specific project needs

Usage Optimization Tips

Maximize efficiency:

Start with Sonnet 4 for most tasks
Switch to Opus only for complex analysis
Use Haiku for simple, repetitive tasks
Monitor usage with CC Usage tool

Recommendations by Experience Level

Beginner Claude Code Users

Start with: Claude 3.5 Sonnet
Why: Lower cost while learning, good capabilities
Upgrade to: Sonnet 4 once comfortable with workflows

Intermediate Developers

Primary model: Claude 4 Sonnet
Why: Best balance for regular development work
Backup: Opus 4 for complex debugging sessions

Advanced/Professional Use

Daily driver: Claude 4 Sonnet
Complex tasks: Claude 4 Opus
Simple tasks: Haiku for cost optimization
Strategy: Dynamic model switching based on task complexity

Future Model Considerations

Staying Updated:

Monitor releases - New models released regularly
Test capabilities - Evaluate new models with your workflows
Update configurations - Adjust default models as capabilities improve
Community feedback - Check r/ClaudeAI for real-world experiences

Choose the right Claude model for your development needs. For most Claude Code users, Claude 4 Sonnet provides the best balance of capability, speed, and cost. Upgrade to Opus for complex tasks, or use 3.5 Sonnet for budget-conscious development.

Claude Model Overview: 3.5 vs 4 Comparison​

Detailed Model Comparison​

Claude 4 Opus - Maximum Capability​

Claude 4 Sonnet - Balanced Excellence (Recommended)​

Claude 3.5 Sonnet - Solid Performance​

Claude 3.5 Haiku - Fast and Economical​

Model Selection Guide​

For Different Development Scenarios​

Performance Comparison​

Switching Models in Claude Code​

Command Line Options​

Environment Variables​

Cost Considerations​

Subscription vs API Pricing​

Usage Optimization Tips​

Recommendations by Experience Level​

Beginner Claude Code Users​

Intermediate Developers​

Advanced/Professional Use​

Future Model Considerations​

Claude Model Overview: 3.5 vs 4 Comparison

Detailed Model Comparison

Claude 4 Opus - Maximum Capability

Claude 4 Sonnet - Balanced Excellence (Recommended)

Claude 3.5 Sonnet - Solid Performance

Claude 3.5 Haiku - Fast and Economical

Model Selection Guide

For Different Development Scenarios

Performance Comparison

Switching Models in Claude Code

Command Line Options

Environment Variables

Cost Considerations

Subscription vs API Pricing

Usage Optimization Tips

Recommendations by Experience Level

Beginner Claude Code Users

Intermediate Developers

Advanced/Professional Use

Future Model Considerations