Claude Code Cheat Sheet – Commands, Shortcuts, Tips

Claude Code is Anthropic’s AI-powered CLI tool that reads your codebase, edits files, runs commands, and manages git workflows directly from the terminal. It operates as an agentic coding assistant: you describe what you want in plain English, and it figures out which files to read, what commands to run, and what changes to make. This cheat sheet covers every command, shortcut, configuration option, and workflow pattern you need to be productive with Claude Code.

Original content from computingforgeeks.com - post 162997

Updated June 2026 for Claude Code 2.1.x with Opus 4.8 as the new default model, Sonnet 4.6, Haiku 4.5, background agents, dynamic workflows, /code-review, the opusplan alias, and the latest slash commands. Every command, flag, and shortcut below was validated against Claude Code 2.1.162.

This cheat sheet is also available as a GitHub repository you can star, fork, and reference offline. Contributions and suggestions are welcome there. For the official changelog and new features, check the Claude Code releases on GitHub.

Installation

Install Claude Code on macOS, Linux, or Windows (WSL):

curl -fsSL https://claude.ai/install.sh | bash

On macOS via Homebrew:

brew install --cask claude-code

On Windows (PowerShell):

irm https://claude.ai/install.ps1 | iex

Verify and authenticate:

claude --version
claude auth login

Keyboard Shortcuts

These work in the interactive Claude Code terminal. This is the most-referenced section, so bookmark it.

Essential Shortcuts

Shortcut	Action
Ctrl+C	Interrupt a running operation. If nothing is running, first press clears input, second exits
Esc	Interrupt Claude mid-turn, keeping the work done so far
Esc + Esc	Clear the input draft, or (when input is empty) open the rewind menu to restore a checkpoint
Ctrl+D	Exit Claude Code
Ctrl+L	Redraw the screen to recover a garbled display
Ctrl+R	Reverse search command history
Shift+Tab	Cycle permission modes (default, acceptEdits, plan, plus any enabled like auto or bypassPermissions)
Ctrl+G	Open input in external editor (also Ctrl+X Ctrl+E)
Ctrl+O	Toggle the transcript viewer (detailed tool usage, expands collapsed MCP calls)
Ctrl+T	Toggle the task list
Ctrl+B	Move a running bash command or agent to the background (tmux: press twice)
Ctrl+X Ctrl+K	Kill all running background subagents (press twice within 3 seconds)

Input and Editing

Shortcut	Action
\ + Enter	New line, works in every terminal
Ctrl+J	New line, works in any terminal with no configuration
Option+Enter (Mac) / Alt+Enter (Linux/Win)	New line (platform default)
Shift+Enter	New line in iTerm2, WezTerm, Ghostty, Kitty, Warp, Apple Terminal, Windows Terminal. Run /terminal-setup for VS Code, Cursor, Zed
Ctrl+A / Ctrl+E	Move cursor to start / end of line
Ctrl+K	Delete to end of line
Ctrl+U	Delete from cursor to line start
Ctrl+W	Delete the previous word
Ctrl+Y	Paste text deleted with Ctrl+K/U/W
Alt+B / Alt+F	Move cursor back/forward one word (macOS needs Option set as Meta)
Cmd+V (Mac) / Ctrl+V or Alt+V (Linux/Win/WSL)	Paste image from clipboard
Up/Down	Move cursor, then navigate command history at the edges

Model and Mode Switching

Shortcut	Action
Option+P (Mac) / Alt+P (Linux/Win)	Switch model (Sonnet/Opus/Haiku)
Option+T (Mac) / Alt+T (Linux/Win)	Toggle extended thinking
Option+O (Mac) / Alt+O (Linux/Win)	Toggle fast mode
Shift+Tab / Alt+M	Cycle permission mode (all platforms)
?	Show all shortcuts (in the transcript viewer)

Quick Prefixes

Prefix	Action
/	Open slash command menu
!	Run bash command directly
@	Autocomplete file path mention

Slash Commands Reference

Session and Context Management

Command	What It Does
/clear	Wipe conversation history and free context window
/compact [focus]	Summarize conversation to free context – optionally focus on specific topic
/cost	Show token usage and API cost for current session
/context	Visualize what is consuming your context window
/resume	Pick and resume a previous session
/rename [name]	Name current session for easy resuming later
/rewind	Rewind to a previous checkpoint
/diff	View interactive diff of all changes made
/copy	Copy last response to clipboard
/export [file]	Export conversation as text file

Configuration and Model

Command	What It Does
/model [name]	Switch model (sonnet, opus, haiku)
/effort [level]	Set reasoning effort (low, medium, high, xhigh, max). Opus 4.8 defaults to high; Opus 4.7 to xhigh.
/config	Open settings interface
/permissions	View and manage tool permissions
/mcp	Manage MCP server connections
/terminal-setup	Configure terminal keybindings for your shell
/theme	Change color theme
/vim	Toggle vim keybinding mode

Project and Code Tools

Command	What It Does
/init	Initialize project, generating a CLAUDE.md with project context
/memory	View and edit CLAUDE.md files and auto-memory
/code-review [level] [--fix] [--comment]	Review the diff for bugs and cleanups. --fix applies findings, --comment posts inline PR comments, ultra runs a cloud multi-agent review
/simplify [target]	Cleanup-only review (reuse, simplification, efficiency) that auto-applies fixes. Use /code-review to hunt bugs
/review [PR]	Review a pull request locally in the current session
/security-review	Scan pending changes for security vulnerabilities
/pr-comments [PR]	Fetch and address GitHub PR review comments
/add-dir [path]	Add another directory to the working context
/plan	Enter plan mode, a read-only exploration before making changes
/branch [name]	Branch the current conversation to try a different direction without losing this one
/fork [directive]	Spawn a background subagent that inherits the full conversation and reports back when done
/goal [condition]	Keep working across turns until a stated condition is met
/batch [task]	Decompose a large change into 5 to 30 units and run each in its own parallel worktree
/debug [description]	Troubleshoot problems in the current session

System and Account

Command	What It Does
/help	Show all available commands
/doctor	Diagnose installation, settings, auth, and MCP issues
/insights	Generate session analysis report – patterns, efficiency, suggestions
/status	Show version, model, and account info
/login / /logout	Sign in or out
/bug	Submit a bug report with session logs
/stats	View usage patterns, daily streaks, and session history
/usage	Show plan usage and rate limits
/release-notes	View changelog for current version
/loop [interval] [prompt]	Run a prompt or command on a recurring schedule
/voice	Toggle push-to-talk voice dictation (hold Space)
/schedule	Create, update, list, or run scheduled remote agents (cron tasks)
/fast	Toggle fast mode (same model, faster output)
/hooks	View and manage configured hooks
/desktop	Hand off current session to the Desktop app
/teleport	Pull a web/iOS session into your terminal
/remote-control	Continue this local session from claude.ai or the Claude app on another device
/reload-skills	Re-scan skill and command directories so on-disk changes apply without a restart
/sandbox	Toggle sandbox mode (supported platforms only)
/recap	Summarize what has happened in the session so far
/statusline	Configure the status line from a description or your shell prompt
/privacy-settings	View and update privacy settings (Pro and Max)

CLI Flags – Non-Interactive and Automation

Starting Sessions

Claude Code reads your current directory as the project root. Launch it from the repo where you want work to happen:

# Start interactive session
claude

# Start with initial prompt
claude "refactor the auth module"

# Continue most recent session
claude -c

# Resume specific session by name
claude -r "auth-refactor"

# Name a session for later
claude -n "feature-payments"

# Run in isolated git worktree
claude -w feature-branch

# Run in worktree with tmux panes
claude -w feature-branch --tmux

# Resume session linked to a GitHub PR
claude --from-pr 42

# Fork a session (new ID, keeps context)
claude -c --fork-session

# Enable auto mode (AI decides permissions)
claude --permission-mode auto

# Skip all permission prompts (sandboxes and containers only)
claude --dangerously-skip-permissions

# Add bypassPermissions to the Shift+Tab cycle without starting in it
claude --permission-mode plan --allow-dangerously-skip-permissions

# Bare mode (skip hooks, plugins, auto-memory) for fast scripted calls
claude --bare

Print Mode (Non-Interactive / Piping)

The -p flag runs Claude Code non-interactively: it processes the prompt and exits. This is the key to integrating Claude Code into scripts, CI/CD pipelines, and Unix pipes:

# Simple query
claude -p "explain this error in server.log"

# Pipe input
cat error.log | claude -p "what caused this crash?"

# Git diff review
git diff main | claude -p "review for security issues"

# JSON output for scripting
claude -p "list all TODO comments" --output-format json

# Structured output with schema validation
claude -p "extract function names from auth.py" \
  --output-format json \
  --json-schema '{"type":"object","properties":{"functions":{"type":"array","items":{"type":"string"}}}}'

# Auto-approve tools (careful with this)
claude -p "run tests and fix failures" --allowedTools "Bash,Read,Edit"

# Set spending limit
claude -p "refactor the API layer" --max-budget-usd 5.00

# Limit turns
claude -p "fix the bug" --max-turns 3

# Fallback model when primary is overloaded
claude -p "review this code" --fallback-model haiku

# Restrict available tools
claude -p "analyze this" --tools "Read,Grep,Glob"

# Block specific tools (deny list)
claude -p "refactor auth module" --disallowedTools "Bash(rm:*),Bash(sudo:*)"

# Override system prompt entirely
claude -p "review this code" --system-prompt "You are a security auditor. Focus only on vulnerabilities."

# Append to default system prompt
claude -p "explain this function" --append-system-prompt "Always include time complexity analysis."

# Load MCP servers from external config file
claude -p "check open issues" --mcp-config ./ci-mcp.json

# Disable session persistence (ephemeral, for CI/CD)
claude -p "run lint check" --no-session-persistence

# Debug mode (logs API calls, tool usage, timings)
claude -p "fix the build" --debug

# Debug with category filter
claude -p "fix the build" --debug "api,hooks"

# Write debug output to a file
claude -p "fix the build" --debug-file /tmp/claude-debug.log

# Select a specific agent
claude -p "review auth.py" --agent code-reviewer

# Streaming JSON output (realtime events for SDK and automation)
claude -p "fix the build" --output-format stream-json --verbose

# Streaming JSON input
claude -p --input-format stream-json --output-format stream-json

# Pin a specific session ID (must be a valid UUID)
claude -p "run lint" --session-id 550e8400-e29b-41d4-a716-446655440000

# Load extra settings inline or from a file (overrides matching keys for this run)
claude -p "audit deps" --settings ./ci-settings.json

# Only load specific setting sources
claude -p "check types" --setting-sources user,project

# Replace the default system prompt from a file
claude -p "review" --system-prompt-file ./reviewer.txt

# Improve prompt-cache reuse across users and machines in scripted runs
claude -p "lint" --exclude-dynamic-system-prompt-sections

# Enable Chrome browser integration
claude --chrome

Model and Effort Flags

Pick a model and reasoning budget up front instead of toggling mid-session. Flags stick for the session they start:

# Use specific model
claude --model opus
claude --model sonnet
claude --model haiku

# Set reasoning effort
claude --effort high    # More thorough (costs more)
claude --effort low     # Faster, cheaper

# Custom system prompt
claude --append-system-prompt "Always use TypeScript. Never use any."

# Load system prompt from file
claude --append-system-prompt-file ./coding-rules.txt

CLAUDE.md – Project Instructions

CLAUDE.md is the single most important file for customizing Claude Code behavior on a per-project basis. It is loaded automatically at the start of every session. For a deep dive into the full directory structure, including rules, agents, skills, and settings, see the .claude directory guide.

File Locations and Scope

Location	Scope	Shared with Team?
./CLAUDE.md	This project only	Yes (commit to git)
./.claude/CLAUDE.md	This project only	Yes (commit to git)
~/.claude/CLAUDE.md	All your projects	No (personal)
.claude/rules/*.md	Path-specific rules	Yes (commit to git)

Example CLAUDE.md

Create the file at the project root. Claude Code reads it on every session start in that directory:

vi CLAUDE.md

Add your project instructions:

# My Project

## Build and Test
- Run tests: `npm test`
- Build: `npm run build`
- Lint: `npm run lint`

## Code Style
- Use TypeScript strict mode
- Prefer functional components in React
- All API responses must include error handling
- Never commit .env files

## Architecture
- Backend: Express.js + PostgreSQL
- Frontend: React + TailwindCSS
- Auth: JWT tokens stored in httpOnly cookies

See @README.md for project overview.
See @package.json for available scripts.

The @filename syntax imports content from other files, and Claude reads them automatically.

Path-Specific Rules

Rules that only apply to certain files. Create .claude/rules/api.md:

vi .claude/rules/api.md

Add frontmatter with path patterns:

---
paths:
  - "src/api/**/*.ts"
---

# API Rules
- All endpoints must validate input with Zod
- Return proper HTTP status codes
- Include rate limiting on public endpoints

Generate a CLAUDE.md automatically for any project with /init.

Permission Modes

Claude Code asks permission before running commands or editing files. Toggle between modes with Shift+Tab. For production lockdown configurations, see the DevOps setup guide which covers permission rules, safety hooks, and CLAUDE.md hardening for infrastructure work.

Mode	Behavior	Use Case
default	Prompts on first use of each tool	Normal interactive work
plan	Read-only – no edits, no commands	Safe exploration and planning
acceptEdits	Auto-approves file edits, prompts for commands	Trusted editing sessions
dontAsk	Auto-denies unless pre-approved	Strict control
auto	AI classifier decides allow/deny per tool call	Trusted projects with clear CLAUDE.md rules
bypassPermissions	Skips all prompts (dangerous)	Containers/sandboxes only

Pre-Approve Specific Tools

In .claude/settings.json or via the CLI:

# Allow git commands and file reads without prompting
claude --allowedTools "Read,Bash(git *)"

# Block dangerous tools explicitly
claude --disallowedTools "Bash(rm:*),Bash(sudo:*),Bash(chmod:*)"

# Combine both: allow some, block others
claude --allowedTools "Bash(git:*),Read,Edit" --disallowedTools "Bash(rm -rf:*)"

Or in settings:

vi .claude/settings.json

Add permission rules:

{
  "permissions": {
    "allow": [
      "Read",
      "Bash(git *)",
      "Bash(npm run *)",
      "Bash(docker compose *)"
    ],
    "deny": [
      "Bash(rm -rf *)"
    ]
  }
}

Models and Effort Levels

Alias	Resolves To	Best For
opus	Claude Opus 4.8	Complex architecture, long agentic runs, hard multi-file refactors. The default model on Max and API tiers
sonnet	Claude Sonnet 4.6	Daily coding: edits, refactors, tests. The default on Pro and Team Standard
haiku	Claude Haiku 4.5	Simple tasks, quick questions, cheap background work
opusplan	Opus, then Sonnet	Opus reasoning during plan mode, then auto-switches to Sonnet for execution
opus[1m] / sonnet[1m]	1M-token context	Long sessions over large codebases. Opus 1M is included on Max, Team, and Enterprise
default / best	Tier default / most capable	default reverts to your account’s recommended model; best always picks the most capable (currently Opus)

Switch models mid-session with /model opus or Option+P (Mac) / Alt+P (Linux/Windows). As of recent builds, the /model picker saves your choice as the default for new sessions (press s to switch for the current session only). Aliases like opus always point to the latest release, so pin a full name (claude-opus-4-8) when you need a fixed version. Opus 4.8 requires Claude Code 2.1.154 or later, so run claude update if /model does not list it.

Effort levels control how much adaptive reasoning Claude applies. The available levels depend on the model: Opus 4.8 and Opus 4.7 support all five, while Sonnet 4.6 and Opus 4.6 stop at high (asking for xhigh on those falls back to high).

Level	Use Case
/effort low	Short, scoped, latency-sensitive tasks that are not intelligence-sensitive
/effort medium	Routine refactors, single-file changes, test generation
/effort high	Multi-file edits, debugging, non-trivial work. Default on Opus 4.8, Opus 4.6, and Sonnet 4.6.
/effort xhigh	Design decisions, tricky cross-module refactors, gnarly bugs. Default on Opus 4.7. Available only on Opus 4.8 and 4.7
/effort max	The hardest problem of the week. Deepest reasoning, no token cap, session-only, and prone to overthinking
/effort ultracode	A Claude Code setting rather than a model level. Sends xhigh per message and has Claude orchestrate a dynamic workflow of background agents for substantive tasks. Session-only

Set effort for a single session at launch with claude --effort high, or globally with the CLAUDE_CODE_EFFORT_LEVEL environment variable, which overrides every other source. Run /effort auto to reset to the model default.

For one-off deep reasoning without changing your session effort, put the word ultrathink anywhere in your prompt. Claude Code recognizes it and adds an in-context instruction for that turn only. Note that the older “think”, “think hard”, and “think harder” phrases are no longer special keywords; they are passed through as ordinary prompt text, so ultrathink is the one to remember.

MCP Servers – Extend Claude Code

MCP (Model Context Protocol) lets Claude Code connect to external tools and data sources. Configure servers in .mcp.json at the project root or ~/.claude/.mcp.json for all projects.

vi .mcp.json

Example configuration with GitHub and PostgreSQL servers:

{
  "mcpServers": {
    "github": {
      "type": "stdio",
      "command": "npx",
      "args": ["@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "$GITHUB_TOKEN"
      }
    },
    "postgres": {
      "type": "stdio",
      "command": "npx",
      "args": ["@modelcontextprotocol/server-postgres"],
      "env": {
        "DATABASE_URL": "postgresql://user:pass@localhost:5432/mydb"
      }
    }
  }
}

You can also add servers from the command line instead of hand-editing JSON. Claude Code writes the config for you:

# Add an HTTP server
claude mcp add --transport http sentry https://mcp.sentry.dev/mcp

# Add a stdio server with environment variables
claude mcp add github -e GITHUB_PERSONAL_ACCESS_TOKEN=$GITHUB_TOKEN -- npx @modelcontextprotocol/server-github

# List, inspect, or remove a server
claude mcp list
claude mcp get github
claude mcp remove github

Manage MCP connections with /mcp in the interactive session or pass a config file on the CLI:

# Load MCP servers from an external config
claude --mcp-config ./team-mcp.json

# Load multiple configs
claude --mcp-config ./github-mcp.json ./db-mcp.json

# Ignore all other MCP sources, only use this config
claude --mcp-config ./ci-mcp.json --strict-mcp-config

The --mcp-config flag is useful in CI/CD where you need consistent MCP server configuration across runs. --strict-mcp-config ensures only the specified servers are loaded, ignoring any from .mcp.json or user settings.

Custom Skills – Your Own Slash Commands

Skills are reusable prompts that show up as slash commands. Create them at .claude/skills/ (project) or ~/.claude/skills/ (personal).

Example, create a deploy skill:

mkdir -p .claude/skills/deploy
vi .claude/skills/deploy/SKILL.md

Add the skill definition:

---
name: deploy
description: Deploy the application to production
argument-hint: "[environment]"
user-invocable: true
---

Deploy the application to the $0 environment (default: staging).

Steps:
1. Run the test suite
2. Build the production bundle
3. Deploy using the deploy script
4. Verify the deployment health check

Now use it: /deploy production

Custom Subagents

Subagents are specialized AI agents that Claude can delegate tasks to. Create them at .claude/agents/:

mkdir -p .claude/agents/code-reviewer
vi .claude/agents/code-reviewer/AGENT.md

Define the agent:

---
name: code-reviewer
description: Expert code reviewer. Use proactively after code changes.
tools: Read, Grep, Glob, Bash
model: sonnet
---

You are a senior code reviewer. When reviewing code:
- Check for security vulnerabilities (SQL injection, XSS, etc.)
- Verify error handling is complete
- Flag any hardcoded secrets or credentials
- Suggest performance improvements
- Check for proper input validation

Claude automatically delegates code review tasks to this agent, or you can invoke it directly with @code-reviewer check my latest changes.

From the CLI, select an agent for the entire session:

# Use a named agent from .claude/agents/
claude --agent code-reviewer

# In print mode (CI/CD)
claude -p "review the latest commit" --agent code-reviewer

# Define agents inline (no files needed)
claude --agents '{"qa": {"description": "QA tester", "prompt": "You are a QA engineer. Write test cases for every change."}}'

Hooks – Automation Triggers

Hooks run shell commands automatically in response to Claude Code events. Configure in .claude/settings.json:

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "hooks": [
          {
            "type": "command",
            "command": "npx prettier --write $(jq -r '.tool_input.file_path')"
          }
        ]
      }
    ],
    "Notification": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "osascript -e 'display notification \"Claude needs input\" with title \"Claude Code\"'"
          }
        ]
      }
    ]
  }
}

Common hook events: SessionStart, PreToolUse, PostToolUse, Stop, Notification, UserPromptSubmit. For real-world hook examples that enforce safety on production servers, see the SSH server management guide.

Context Window Management

Claude Code has a finite context window. Managing it well is the difference between a productive session and hitting walls.

Key Commands

Command	When to Use
/compact	Summarize conversation to free space mid-task
/compact Focus on auth module	Summarize but keep specific context intact
/clear	Complete reset between unrelated tasks
/context	See what is consuming your context

Tips for Long Sessions

• Use /clear between unrelated tasks – do not carry old context into new work
• Run /compact proactively when you notice slowdowns
• Use subagents for verbose operations (test runs, log analysis) – their output stays in the subagent context
• Move detailed instructions to skills instead of typing them every time
• Keep CLAUDE.md under 200 lines – move details to separate files and import with @filename

Git Worktrees – Parallel Work

Work on multiple tasks simultaneously without branch switching conflicts:

# Start Claude in a new worktree
claude -w feature-auth

# Batch changes across many files in parallel
/batch migrate all components from class-based to functional

The -w flag creates an isolated git worktree. Changes happen in the worktree without affecting your main working directory. When the agent finishes, merge the worktree branch back.

Background Agents and Dynamic Workflows

Background agents are full Claude Code sessions that run detached from your terminal, so you can fire off a long task and keep working in the foreground. They keep running after you close the terminal and are managed from a small set of subcommands. This is the largest addition to Claude Code since the cheat sheet first shipped.

Start one from the shell with --bg. It prints a session ID and returns immediately:

# Launch a background agent and get its ID back
claude --bg "investigate the flaky test in tests/auth"

# Run a shell command as a background job instead of a session
claude --bg --exec 'pytest -x'

# Run a specific subagent in the background
claude --bg --agent code-reviewer "review the open PR"

From inside an interactive session, detach the whole thing with /background (alias /bg) and list what is running with /tasks. To watch and dispatch background sessions in a live view, open the agent manager:

claude agents

Manage individual background sessions from the shell by ID. The agent view shows the IDs, or you can list them as JSON for scripting:

# List live background sessions as JSON
claude agents --json

# Attach a background session to this terminal
claude attach 7c5dcf5d

# Tail its recent output
claude logs 7c5dcf5d

# Stop, restart (keeps the conversation), or remove from the list
claude stop 7c5dcf5d
claude respawn 7c5dcf5d
claude rm 7c5dcf5d

Background sessions run under a supervisor process. If the agent view reports that the background service did not respond, inspect or reset it:

# Show supervisor state, version, and worker count
claude daemon status

# Stop the supervisor but keep workers so the next one reconnects
claude daemon stop --any --keep-workers

Dynamic workflows take this further. A single instruction is decomposed into tens or hundreds of background subagents that run in parallel. Trigger one for a substantive task by setting the ultracode effort level, then run /workflows to watch progress live. For a codebase-wide change, /batch splits the work into independent units and runs each in its own git worktree with its own pull request.

Want a leaner session? Set CLAUDE_CODE_DISABLE_AGENT_VIEW=1 to turn off background agents and CLAUDE_CODE_DISABLE_WORKFLOWS=1 to turn off dynamic workflows.

Settings File Reference

File	Scope
.claude/settings.json	Project (shared via git)
.claude/settings.local.json	Project (gitignored, personal)
~/.claude/settings.json	All projects (personal)

Common settings:

{
  "model": "opus",
  "effortLevel": "high",
  "autoMemoryEnabled": true,
  "permissions": {
    "defaultMode": "default",
    "allow": ["Read", "Bash(git *)"],
    "deny": ["Bash(rm -rf *)"]
  }
}

Environment Variables

Variable	Purpose
ANTHROPIC_MODEL	Default model (e.g., opus)
ANTHROPIC_API_KEY	API key for direct API access
CLAUDE_CODE_EFFORT_LEVEL	Default effort (low/medium/high/xhigh/max)
CLAUDE_CODE_DISABLE_AUTO_MEMORY	Set to 1 to disable auto-memory
CLAUDE_CODE_DISABLE_1M_CONTEXT	Set to 1 to disable 1M token context
MAX_THINKING_TOKENS	Custom thinking budget (default varies)
HTTPS_PROXY	HTTP proxy for corporate networks
CLAUDE_CODE_NO_FLICKER	Set to 1 to use the fullscreen TUI renderer (same as tui: "fullscreen"): smooth, flicker-free output with mouse support
ENABLE_TOOL_SEARCH	Set to auto:5 to auto-defer tool definitions when they exceed 5% of context
CLAUDE_CODE_SUBAGENT_MODEL	Model used for all subagents and agent teams (set to inherit for normal resolution)
CLAUDE_CODE_DISABLE_AGENT_VIEW	Set to 1 to turn off background agents
CLAUDE_CODE_DISABLE_WORKFLOWS	Set to 1 to turn off dynamic workflows
CLAUDE_CODE_DISABLE_BACKGROUND_TASKS	Set to 1 to disable background bash tasks
CLAUDE_CODE_TASK_LIST_ID	Share a task list across sessions via a named directory in ~/.claude/tasks/
DISABLE_AUTOUPDATER	Set to 1 to disable automatic updates entirely

The CLAUDE_CODE_NO_FLICKER variable is worth calling out. By default, the terminal renderer redraws the entire output with each token, causing visible flashing in code blocks and tables. With CLAUDE_CODE_NO_FLICKER=1, output streams line-by-line without screen jumps, syntax highlighting stays stable, and table columns stay aligned while populating. It also enables mouse event support (clicking and scrolling). Add it to your shell profile for a noticeably smoother experience:

echo 'export CLAUDE_CODE_NO_FLICKER=1' >> ~/.zshrc
source ~/.zshrc

Or use it in an alias that bundles your preferred defaults:

alias c="CLAUDE_CODE_NO_FLICKER=1 claude --effort max"

This is the same renderer you can turn on permanently with "tui": "fullscreen" in settings. The fullscreen view also unlocks transcript-viewer shortcuts: press ? for the full shortcut panel and { / } to jump between prompts.

File Structure Reference

Claude Code reads configuration from two scopes: your home directory for personal defaults and the project root for repo-specific rules. The tree below maps the files you’ll touch most:

# User-level (personal, all projects)
~/.claude/
  settings.json          # Global settings
  keybindings.json       # Custom keyboard shortcuts
  CLAUDE.md              # Personal instructions
  rules/                 # Personal rules
  agents/                # Personal subagents
  skills/                # Personal skills
  .mcp.json              # Global MCP servers

# Project-level (shared with team)
.claude/
  settings.json          # Project settings (git tracked)
  settings.local.json    # Local overrides (gitignored)
  CLAUDE.md              # Project instructions
  rules/                 # Path-specific rules
  agents/                # Project subagents
  skills/                # Project skills
.mcp.json                # Project MCP servers
CLAUDE.md                # Project instructions (alternative location)

Practical Workflow Tips

Start Every Project Right

The two-minute ritual that makes every subsequent session faster: seed a CLAUDE.md at the project root so Claude knows your conventions without being told each time:

# In your project root
claude
/init

This scans your project and generates a CLAUDE.md with build commands, test instructions, and code conventions. Review and edit it, because this file shapes every future interaction.

Plan Before You Build

Press Shift+Tab to enter plan mode before asking Claude to make changes. In plan mode, Claude reads and analyzes but cannot edit anything. Once you approve the plan, switch back to default mode and say “implement the plan”.

Undo Mistakes Instantly

Press Esc + Esc to open the rewind menu. Choose “Restore code and conversation” to undo both the code changes and the conversation that led to them. This is faster than git stash for quick experiments.

Pipe Everything

Claude Code is a normal Unix citizen on stdin/stdout. Anything you can pipe into grep, you can pipe into claude -p:

# Analyze logs
tail -500 /var/log/app.log | claude -p "find the root cause of errors"

# Review a PR
gh pr diff 42 | claude -p "security review this PR"

# Generate commit message
git diff --staged | claude -p "write a conventional commit message" --model haiku

# Translate
cat README.md | claude -p "translate to Japanese" > README.ja.md

# Docker container analysis
docker ps --format json | claude -p "which containers are using the most resources?"

# Kubernetes pod debugging
kubectl logs deployment/api --tail=200 | claude -p "why are requests failing?"

# Database structure review
pg_dump --schema-only mydb | claude -p "suggest index improvements"

# Summarize recent commits
git log --oneline -20 | claude -p "write release notes from these commits"

# Find config issues
cat /etc/nginx/nginx.conf | claude -p "check for misconfigurations"

For deeper walkthroughs of Docker and Kubernetes workflows with Claude Code, see the Docker guide and Kubernetes guide.

Automation Scripts

Chain multiple claude -p calls in a bash script for repeatable workflows:

#!/bin/bash
# Automated PR review pipeline
git diff HEAD~1 > /tmp/diff.txt
cat /tmp/diff.txt | claude -p "review for security issues" --model sonnet > security_review.md
cat /tmp/diff.txt | claude -p "check for performance regressions" --model sonnet > perf_review.md
cat /tmp/diff.txt | claude -p "write a one-paragraph summary" --model haiku > summary.md

Batch process multiple files:

#!/bin/bash
# Generate docstrings for all Python files missing them
for f in $(grep -rL '"""' src/*.py); do
  claude -p "add docstrings to functions missing them in $f" \
    --allowedTools "Read,Edit" --max-turns 3
done

Generate a changelog from git tags:

git log v1.0.0..v2.0.0 --oneline | \
  claude -p "create a changelog grouped by feature, fix, and chore" \
  --output-format text > CHANGELOG.md

Side Questions with /btw

Need to ask something without derailing the current task? Use /btw:

/btw what was the name of that config file we edited earlier?

The response is ephemeral (not saved to context), low-cost (uses cache), and does not use any tools.

Cost Control

• Use /cost to check spend at any time
• Use Sonnet for most work, Opus only for complex problems
• Use /effort low for simple tasks
• Run /compact to reduce context size (fewer tokens per request)
• Be specific in prompts – vague requests cause more back-and-forth
• Use --max-budget-usd 5.00 in CI/CD to prevent runaway costs

Prompting Tips – Get Better Results

The quality of Claude Code’s output depends heavily on how you prompt it. These patterns consistently produce better results.

Be Specific, Not Vague

Bad Prompt	Good Prompt
“fix the bug”	“the login endpoint returns 500 when email contains a plus sign – fix the input validation in src/auth/login.ts”
“make it faster”	“the /api/users endpoint takes 3s on 10k rows – add database indexing and pagination”
“write tests”	“write unit tests for the calculateDiscount function in src/pricing.ts covering edge cases: zero price, negative quantity, expired coupon”
“clean up the code”	“extract the duplicate validation logic in src/api/orders.ts and src/api/returns.ts into a shared validator”

Use Plan Mode First

For complex tasks, switch to plan mode (Shift+Tab) and ask Claude to explore before coding:

# In plan mode:
"I need to add OAuth2 login with Google. Look at the existing auth flow
in src/auth/ and propose where to add the Google provider without
breaking the current email/password login."

Review the plan, then switch back to default mode and say “implement the plan”.

Give Verification Targets

Tell Claude how to verify its own work:

"Add rate limiting to the /api/auth endpoints. After implementing,
run npm test to make sure nothing breaks, and verify the rate limiter
works by checking the middleware is registered in the Express app."

Use @file Mentions for Context

Point Claude at specific files instead of making it search:

"look at @src/db/schema.ts and @src/api/users.ts - the User model
has a new 'role' field in the schema but the API doesn't expose it.
Add the role field to the GET /users/:id response."

Course-Correct Early

If you see Claude going in the wrong direction, press Ctrl+C to stop and redirect. Do not wait for it to finish a large wrong change. Interrupt and clarify. If it already made bad changes, press Esc + Esc to rewind.

Break Large Tasks Into Steps

Instead of “build a user management system”, split it:

1. “Create the User database schema with id, email, name, role, created_at”
2. “Add CRUD API endpoints for users with input validation”
3. “Write tests for the user endpoints”
4. “Add role-based access control middleware”

Each step gets verified before moving to the next. This avoids wasting tokens on a bad foundation.

Token Saving Strategies

Every message sent to Claude includes the full conversation context. Larger context means higher cost and slower responses. These strategies keep your sessions efficient.

Context Hygiene

Strategy	How	Savings
Clear between tasks	/clear when switching to unrelated work	Biggest impact – resets to zero
Compact proactively	/compact Focus on the auth module changes	Keeps relevant context, drops noise
Check context usage	/context to see what is consuming space	Identifies bloat sources
Use @file mentions	@src/auth.ts instead of “find the auth file”	Avoids exploratory file reads
Use subagents	Delegate verbose tasks (test runs, log analysis)	Output stays in subagent context

Model Selection

Task	Model	Effort
Simple edits, renames, formatting	Sonnet	/effort low
Standard coding, tests, refactoring	Sonnet	/effort medium
Complex debugging, architecture	Opus	/effort high
Quick questions	Haiku (via /btw)	N/A

CLAUDE.md Optimization

• Keep the main CLAUDE.md under 200 lines – it loads on every message
• Move detailed instructions into skills – they only load when invoked
• Use @file imports for large reference docs instead of pasting content
• Put path-specific rules in .claude/rules/ – they only load when Claude touches matching files

MCP and Tool Optimization

• Disable unused MCP servers with /mcp – each server adds tool definitions to context
• Use CLI tools (gh, aws, gcloud) instead of MCP when a single command works
• Set ENABLE_TOOL_SEARCH=auto:5 to auto-defer tool definitions when they exceed 5% of context

CI/CD Budget Controls

Any Claude Code invocation in CI should have a dollar cap and a fallback model. Skip these and one bad prompt can drain your monthly budget in a single failing pipeline:

# Hard spending limit
claude -p "fix failing tests" --max-budget-usd 2.00

# Limit agentic turns
claude -p "review this file" --max-turns 3

# Use cheapest model for simple CI tasks
claude -p "check for linting errors" --model haiku

Diagnostics – /doctor and /insights

Three tools for understanding what Claude Code is doing under the hood:

–debug – Verbose Logging

When you need to see exactly what Claude Code is doing (API calls, tool invocations, timing), use --debug:

# Full debug output to stderr
claude --debug

# Filter to specific categories
claude --debug "api,hooks"

# Write debug logs to a file (keeps terminal clean)
claude --debug-file /tmp/claude-debug.log

This is especially useful when MCP servers are not connecting, hooks are not firing, or API calls are failing silently.

/doctor – Health Check

Run /doctor when something is not working right. It checks:

• Claude Code version and auto-updater status
• Authentication state and token validity
• API connectivity
• Settings file syntax and conflicts
• MCP server health
• Permission configuration

/insights – Session Analysis

Run /insights after a long session to get an analysis report covering:

• Token usage breakdown by category
• Most expensive operations in the session
• Patterns in how you use Claude Code
• Suggestions for improving efficiency
• Time spent waiting vs. actively working

Use this to identify habits that waste tokens and adjust your workflow.

IDE Integrations

Claude Code integrates with VS Code and JetBrains IDEs for inline diffs, context sharing, and side-by-side conversations. Wondering how it stacks up against other AI coding tools? See the OpenCode vs Claude Code vs Cursor comparison.

VS Code

• Install the “Claude Code” extension from the VS Code marketplace
• Open Command Palette (Cmd+Shift+P on Mac / Ctrl+Shift+P on Linux/Windows) and search “Claude Code”
• Works with Cursor editor too

JetBrains (IntelliJ, PyCharm, WebStorm, etc.)

• Install “Claude Code” from the JetBrains Marketplace
• Works across all JetBrains IDEs
• Supports interactive diffs and context sharing

Start Claude with IDE auto-detection:

claude --ide

Quick Reference Card

The 20 commands and shortcuts you will use every day:

Action	How
Start new session	claude
Continue last session	claude -c
Initialize project	/init
Switch to plan mode	Shift+Tab
Switch model	/model opus or Option+P / Alt+P
Undo changes	Esc + Esc
Free context space	/compact
Start fresh	/clear
Check costs	/cost
Review changes	/diff
Security scan	/security-review
Name session	/rename my-feature
Resume session	/resume or claude -r
Mention a file	@path/to/file
Run bash directly	!ls -la
Multiline input	\ + Enter
Cancel generation	Ctrl+C
Exit	Ctrl+D
Non-interactive	claude -p "query"
Show all commands	/help

Auto Mode

Auto mode uses an AI classifier to decide whether each tool call needs your approval. Instead of prompting on every command, it allows safe operations (reads, git status, test runs) and blocks risky ones (force push, rm -rf, production deploys) automatically. Enable it with --permission-mode auto or press Shift+Tab to cycle to it.

Inspect the classifier rules with the claude auto-mode subcommand:

# View current auto-mode config
claude auto-mode config

# View default allow/deny rules
claude auto-mode defaults

# Get AI feedback on your custom rules
claude auto-mode critique

Customize rules in .claude/settings.json or ~/.claude/settings.json under the autoMode key with allow, soft_deny, and environment arrays. The classifier reads these plus the defaults to make per-tool-call decisions.

/loop – Recurring Tasks

The /loop slash command runs a prompt or another slash command on a repeating interval within your session. Useful for polling deploy status, watching test results, or checking a service health endpoint.

# Check deploy status every 5 minutes
/loop 5m check if the deploy on staging is complete

# Run tests every 10 minutes (default interval)
/loop /test

# Custom interval with a slash command
/loop 2m /security-review

The loop runs in the background until you stop it or end the session. Each iteration gets its own context, so long-running loops do not bloat the conversation.

Subcommands Reference

Claude Code provides subcommands for management tasks outside of interactive sessions:

Subcommand	What It Does
claude agents	Open the agent view to monitor and dispatch parallel background sessions (--json for scripting)
claude attach <id>	Attach a background session to this terminal
claude logs <id>	Print recent output from a background session
claude stop <id>	Stop a background session (also claude kill)
claude respawn <id>	Restart a background session with its conversation intact
claude rm <id>	Remove a background session from the list (transcript stays on disk)
claude daemon status	Show the background-session supervisor state and worker count
claude auth	Manage authentication (login, logout, status)
claude auto-mode config	Print effective auto-mode classifier rules
claude auto-mode defaults	Show default allow/deny rules
claude auto-mode critique	Get AI feedback on your custom auto-mode rules
claude doctor	Health check for auto-updater, auth, MCP, settings
claude install [target]	Install a specific version (stable, latest, or a version number)
claude mcp	Configure and manage MCP servers from the CLI
claude plugin	Manage plugins (alias claude plugins)
claude project purge [path]	Delete all local Claude Code state for a project (transcripts, tasks, history)
claude remote-control	Run a Remote Control server to drive Claude Code from claude.ai or the Claude app
claude ultrareview [target]	Run a cloud-hosted multi-agent code review and print the findings (--json, --timeout)
claude setup-token	Set up a long-lived auth token (requires subscription)
claude update	Check for and install updates

Claude Code for DevOps – Full Guide Series

This cheat sheet covers the commands and configuration. The DevOps series goes deeper with real-world demos, tested on actual infrastructure:

• Set Up Claude Code for DevOps Engineers – CLAUDE.md rules, permission lockdowns, hooks, and safety configuration for production use
• Manage Servers with Claude Code via SSH – multi-server health checks, log analysis, config audits, and incident response over SSH
• Build and Debug Docker Containers with Claude Code – Dockerfile generation, multi-stage builds, Compose workflows, and container debugging
• Deploy Infrastructure with Claude Code and Terraform – HCL generation, plan review, state management, and module refactoring
• Generate and Debug Ansible Playbooks with Claude Code – playbook generation, role scaffolding, multi-OS support, and Vault integration
• Deploy and Debug Kubernetes Apps with Claude Code – manifest generation, pod debugging, Helm chart management, and cluster troubleshooting
• Set Up Claude Code in GitHub Actions for Infrastructure Review – automated PR reviews, Terraform plan analysis, and CI/CD integration

Frequently Asked Questions

Conclusion

Claude Code replaces a large part of the manual terminal workflow for developers and sysadmins. The key to getting the most out of it: set up CLAUDE.md for every project, use plan mode before making changes, keep context clean with /compact and /clear, and use print mode (-p) to integrate it into your existing scripts and CI/CD pipelines. If you need multi-provider support, check out OpenCode (75+ providers), Aider (git-native AI pair programming), or Claw Code (open-source Claude Code alternative in Rust). For the latest features and documentation, visit the official Claude Code docs.