Claude Code Guide

This skill provides comprehensive guidance for Claude Code - the agentic coding tool from Anthropic.

What is Claude Code?

Claude Code is an agentic coding assistant that operates directly in your terminal. Unlike chat-based AI tools, Claude Code:

• Sees your codebase: Reads files, understands project structure, follows imports
• Takes action: Edits files, runs commands, creates commits, manages git workflows
• Verifies results: Runs tests, checks build output, validates changes
• Learns context: Remembers project conventions via CLAUDE.md files

The Agentic Loop

Claude Code operates in a continuous gather → act → verify loop:

┌─────────────────────────────────────────────────────┐
│                   AGENTIC LOOP                       │
├─────────────────────────────────────────────────────┤
│  1. GATHER CONTEXT                                   │
│     • Read files, search code, explore structure     │
│     • Understand current state and requirements      │
│                                                      │
│  2. TAKE ACTION                                      │
│     • Edit files, run commands, create content       │
│     • May require permission for sensitive ops       │
│                                                      │
│  3. VERIFY RESULTS                                   │
│     • Check command output, run tests                │
│     • Validate changes meet requirements             │
│                                                      │
│  4. REPEAT or COMPLETE                               │
│     • Continue if more work needed                   │
│     • Report results when done                       │
└─────────────────────────────────────────────────────┘

Read more: references/core/agentic-loop.md

Key Features Quick Reference

Feature	Description	Learn More
Tools	File ops, search, bash, web access	references/core/tools.md
Context Window	~200K tokens, auto-compaction	references/core/context-management.md
CLAUDE.md	Project-specific instructions	references/configuration/memory.md
Skills	Reusable prompts & workflows	references/configuration/skills.md
Hooks	Shell commands on events	references/configuration/hooks.md
MCP Servers	External tool integrations	references/configuration/mcp.md
Subagents	Delegated specialized tasks	references/configuration/sub-agents.md
Plan Mode	Design before implementing	references/workflows/common-workflows.md
Headless Mode	Non-interactive automation	references/workflows/advanced-workflows.md

Extension Points Comparison

Choose the right extension mechanism for your needs:

Mechanism	Best For	Scope	Complexity
CLAUDE.md	Project conventions, coding standards, context	Project	Low
Skills	Reusable prompts, workflows, templates	User/Project	Low-Medium
Hooks	Automation, validation, logging, side effects	User/Project	Medium
MCP Servers	External APIs, databases, custom tools	User/Project	Medium-High
Subagents	Specialized tasks, parallel work, isolation	User/Project	Medium

When to Use What

Use CLAUDE.md when:

• Defining coding standards ("use tabs, not spaces")
• Documenting project architecture
• Specifying test commands
• Setting up file organization rules

Use Skills when:

• Creating reusable workflows (/commit, /review)
• Building prompt templates with arguments
• Packaging documentation for reference
• Defining specialized behaviors

Use Hooks when:

• Running commands before/after actions
• Validating or blocking tool usage
• Logging activity
• Auto-formatting code on save

Use MCP Servers when:

• Connecting to external APIs (GitHub, Jira, databases)
• Adding custom tool capabilities
• Integrating with existing services
• Providing resources from external sources

Use Subagents when:

• Delegating specialized investigations
• Running parallel analysis tasks
• Isolating context for focused work
• Creating custom agent personas

Navigation Guide

Understanding How Claude Code Works

• How does the agentic loop work? → references/core/agentic-loop.md
• What tools does Claude have? → references/core/tools.md
• How does context management work? → references/core/context-management.md

Configuration & Setup

• How do I set up CLAUDE.md? → references/configuration/memory.md
• How do I create skills? → references/configuration/skills.md
• How do I configure hooks? → references/configuration/hooks.md
• How do I add MCP servers? → references/configuration/mcp.md
• How do I create subagents? → references/configuration/sub-agents.md

Workflows & Best Practices

• Common tasks (exploration, debugging, PRs) → references/workflows/common-workflows.md
• Advanced patterns (parallel, CI/CD, headless) → references/workflows/advanced-workflows.md
• Best practices & tips → references/best-practices.md

CLI Reference

• Commands, flags, and options → references/cli-reference.md

Quick Tips

Effective Prompting

# Be specific about verification
"Add input validation to the signup form. Run the tests to verify."

# Provide context
"The auth system uses JWT tokens stored in httpOnly cookies.
Add a logout endpoint that clears the cookie."

# Request exploration first
"Explore how error handling works in this codebase, then
suggest improvements to the API error responses."

Keyboard Shortcuts

Key	Action
Enter	Send message (configurable)
Esc	Cancel current generation
Ctrl+C	Interrupt / Exit
Tab	Accept autocomplete
Up/Down	Navigate history

Essential Commands

Command	Purpose
/help	Show all commands
/compact	Reduce context usage
/clear	Start fresh conversation
/rewind	Undo to checkpoint
/status	Show current state
/config	Open settings
/review	Review code changes
/pr-comments	Address PR feedback

Common Questions

Q: How much context does Claude Code have? A: ~200K tokens. Use /compact if running low. See references/core/context-management.md.

Q: Can Claude Code run commands without asking? A: Depends on permission mode. Safe commands auto-approve; destructive ones ask. See references/core/agentic-loop.md.

Q: How do I share context across sessions? A: Use CLAUDE.md files for persistent context. See references/configuration/memory.md.

Q: Can I use Claude Code in CI/CD? A: Yes, with headless mode (claude -p). See references/workflows/advanced-workflows.md.

Q: How do I add custom tools? A: Via MCP servers. See references/configuration/mcp.md.

IDE Integration

Claude Code integrates with VS Code and JetBrains IDEs:

VS Code: Install "Claude Code" extension

• Cmd+Esc (Mac) / Ctrl+Esc (Windows/Linux) to open
• Automatic file sync with editor
• Inline diff viewing

JetBrains: Install "Claude Code" plugin

• Same keyboard shortcut
• Project context awareness
• Integrated terminal

Getting Help

• In Claude Code: Type /help for commands
• Documentation: https://docs.anthropic.com/claude-code
• Issues: https://github.com/anthropics/claude-code/issues