CtrlK
Template:Infobox software
Claude Code is an AI-powered command-line tool for agentic coding developed by Anthropic. First released as a beta research preview alongside Claude 3.7 Sonnet on February 24, 2025, and made generally available on May 22, 2025, Claude Code enables developers to delegate coding tasks to Claude directly from their terminal.[1][2]
On September 29, 2025, Anthropic released Claude Code version 2.0 with significant enhancements including checkpoints for safe rollbacks, a native VS Code extension, terminal v2.0 UX improvements, and the renamed Claude Agent SDK (formerly Claude Code SDK).[3][4]
Claude Code functions as an AI pair programmer that understands entire codebases and assists developers through natural language commands. The tool executes routine tasks, explains complex code, handles Git workflows, and performs multi-file edits without requiring additional servers, remote code indexing, or complex setup.[5] It operates on the Unix philosophy, making it composable and scriptable within existing developer workflows.[6]
The tool utilizes Claude models, with Claude Sonnet 4.5 (model ID: claude-sonnet-4-5-20250929) as the default model as of September 29, 2025. Users with Max subscriptions also have access to Claude Opus 4.1 (claude-opus-4-1-20250805) for more complex tasks.[4] Claude Code achieved state-of-the-art performance on the SWE-bench Verified benchmark with a 77.2% score for Claude Sonnet 4.5, surpassing previous models and competitors.[4][7]
As of September 2025, Claude Code generates run rate revenue of over $500 million and serves more than 300,000 business accounts, with over 5 million downloads on npm.[8][9]
Claude Code provides comprehensive development assistance through several key features:
| Feature | Description | Example Tasks |
|---|---|---|
| Build Features from Descriptions | Describe desired functionality in plain English; Claude creates a plan, writes code, and verifies it works | Refactors, API migrations, new feature implementation |
| Debug and Fix Issues | Describe bugs or paste error messages; Claude analyzes the codebase, identifies problems, and implements fixes | "Why is auth failing on refresh?" |
| File Management | Edit files and fix bugs across entire codebases with automatic context awareness | Multi-file refactoring |
| Code Analysis | Answer questions about code architecture and logic using agentic search | "Map out the payment module" |
| Testing & Quality | Execute and fix tests, linting, and other quality checks | "Run tests and fix failures in CI" |
| Version Control | Search git history, resolve merge conflicts, create commits and pull requests | "Open a PR implementing ticket #124" |
| Codebase Understanding | Agentic search to understand project structure without manual context selection | Automatic project exploration |
| Multi-file Editing | Make coordinated changes across multiple files simultaneously | Large-scale refactoring |
| Command Execution | Run shell commands and command line tools | "Build and start the dev server" |
| Checkpoints | Automatically save code state before changes with instant rollback capability (v2.0+) | Safe experimentation |
The tool includes several advanced capabilities that distinguish it from traditional coding assistants:
| Component | Requirement |
|---|---|
| Operating System | macOS 10.15+, Ubuntu 20.04+/Debian 10+, Windows 10+ (via WSL 1/2 or Git for Windows) |
| Hardware | Minimum 4GB RAM (8GB recommended for large codebases) |
| Software | Node.js 18+ and npm |
| Network | Internet connection required (authentication & model inference) |
| Supported Shells | Bash, Zsh, Fish |
| Dependencies | Git, ripgrep (recommended) |
| Availability | Only in Anthropic's supported countries |
The tool is available only in countries and regions supported by Anthropic.[14]
Claude Code can be installed through multiple methods:
# Prerequisite: Node.js 18+ npm install -g @anthropic-ai/claude-code # Start in your project directory cd your-awesome-project claude
The current stable version is 1.0.128 as of September 2025.[9]
# For macOS, Linux, WSL - Stable version curl -fsSL https://claude.ai/install.sh | bash # Latest version curl -fsSL https://claude.ai/install.sh | bash -s latest # Specific version (example: 1.0.128) curl -fsSL https://claude.ai/install.sh | bash -s 1.0.128
For Windows:
irm https://claude.ai/install.ps1 | iex
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd
Post-installation, run `claude doctor` to verify. For Alpine Linux or musl-based systems, install additional dependencies like libgcc, libstdc++, and ripgrep.[14]
After global installation, use `claude migrate-installer` to switch to local mode to avoid permission issues with auto-updates.[14]
Authenticate via Claude Console (default for billing), Claude App (for Pro/Max plans), or enterprise platforms like Amazon Bedrock and Google Cloud Vertex AI. Credentials are stored securely.[14][15]
Claude Code supports various command-line options for different use cases:
| Command | Description | Example |
|---|---|---|
| claude | Start interactive REPL | claude |
| claude "query" | Start REPL with initial prompt | claude "explain this project" |
| claude -p "query" | Query via SDK, then exit | claude -p "explain this function" |
| claude -p "query" | Process piped content | claude -p "explain" |
| claude -c | Continue most recent conversation | claude -c |
| claude -c -p "query" | Continue via SDK | claude -c -p "Check for type errors" |
| claude -r "<session-id>" "query" | Resume session by ID | claude -r "abc123" "Finish this PR" |
| claude --model | Select AI model (sonnet/opus) | claude --model opus |
| claude --resume | Resume from recent sessions | claude --resume |
| claude --continue | Continue last session | claude --continue |
| claude update | Update to latest version | claude update |
| claude mcp | Configure MCP servers | See MCP docs |
Additional flags enhance functionality:
| Flag | Description | Example |
|---|---|---|
| --add-dir | Add working directories | claude --add-dir ../apps ../lib |
| --allowedTools | Allow tools without prompt | claude --allowedTools "Bash(git log:*)" "Read" |
| --disallowedTools | Disallow tools | claude --disallowedTools "Edit" |
| --print, -p | Print response without interactive mode | claude -p "query" |
| --append-system-prompt | Append to system prompt (with --print) | claude --append-system-prompt "Custom instruction" |
| --output-format | Output format (text, json, stream-json) | claude -p --output-format json |
| --input-format | Input format (text, stream-json) | claude -p --input-format stream-json |
| --verbose | Enable verbose logging | claude --verbose |
| --max-turns | Limit agentic turns | claude -p --max-turns 3 |
| --permission-mode | Set permission mode | claude --permission-mode plan |
| --dangerously-skip-permissions | Skip permissions (use with caution) | claude --dangerously-skip-permissions |
Within the interactive REPL, users can access various slash commands:
| Command | Description |
|---|---|
| /clear | Reset context window |
| /bug | Report issues directly to Anthropic |
| /config | Access configuration settings |
| /model | Switch between available models |
| /status | Check usage limits and billing |
| /vim | Enable Vim keybindings |
| /terminal-setup | Configure terminal shortcuts |
| /rewind | Restore to previous checkpoint (v2.0+) |
| /agents | Create custom subagents |
| /init | Generate CLAUDE.md documentation file |
| /compact | Summarize conversation to save context |
| /export | Export conversation for sharing |
| /statusline | Customize status line display |
| /install-github-app | Set up GitHub integration |
| /login | Switch authentication |
| /logout | Log out |
Claude Code follows Unix philosophy principles, allowing integration with existing command-line tools:[6]
# Process piped content tail -f app.log | claude -p "alert me if you see repeated 5xx and suggest fixes" # Batch annotate files for file in *.js; do claude -p "Add JSDoc comments to this file:" < "$file" > "${file}.documented" done # Automated workflows for f in src/**/*.ts; do claude -p "Add TSDoc to this file:" < "$f" > "${f%.ts}.annotated.ts" done
On September 29, 2025, Anthropic renamed the Claude Code SDK to the Claude Agent SDK, reflecting its broader capabilities beyond coding.[13] The SDK provides developers with the same infrastructure that powers Claude Code, including:
| Component | Description |
|---|---|
| Context Management | Automatic compaction and context management |
| Rich Tool Ecosystem | File operations, code execution, web search, and MCP extensibility |
| Advanced Permissions | Fine-grained control over agent capabilities |
| Production Essentials | Built-in error handling, session management, and monitoring |
| Optimized Integration | Automatic prompt caching and performance optimizations |
import anyio from claude_code_sdk import query async def main(): async for message in query(prompt="What is 2 + 2?"): print(message) anyio.run(main)
The SDK is available for Python and TypeScript, enabling developers to build various types of agents including SRE agents, code review agents, legal assistants, and finance advisors.[13]
Claude Code is available through multiple subscription tiers and deployment options:[15]
| Plan | Price (USD) | Features | Best For |
|---|---|---|---|
| Pro | $20/month ($17/mo annual) |
10-40 prompts every 5 hours Sonnet 4.5 access only 40-80 hours of Sonnet 4.5 weekly |
Light work on small repositories (<1,000 lines) |
| Max 5x Pro | $100/month | 50-200 prompts every 5 hours Sonnet 4.5 and Opus 4.1 access 140-280 hours of Sonnet 4.5 weekly 15-35 hours of Opus 4.1 weekly |
Regular use with medium codebases |
| Max 20x Pro | $200/month | 200-800 prompts every 5 hours Sonnet 4.5 and Opus 4.1 access 240-480 hours of Sonnet 4.5 weekly 24-40 hours of Opus 4.1 weekly |
Power users with large codebases |
| API | Pay-as-you-go | Standard API pricing $3/$15 per million tokens (Sonnet 4.5) No per-seat fees |
Enterprise deployments and custom integrations |
| Team | Custom | Centralized billing Admin controls |
Small to medium teams |
| Enterprise | Custom | SSO and SCIM Priority support |
Large organizations |
| Education | Custom | University-wide access Discounted rates |
Academic institutions |
Enterprise customers can also access Claude Code through Amazon Bedrock and Google Cloud Vertex AI.[5]
Claude Code implements automatic model switching to prevent users from exhausting their limits too quickly:
Users can override this behavior using the `/model` command.[15]
Claude Code has demonstrated strong performance on coding benchmarks:
| Benchmark | Model | Score | Notes |
|---|---|---|---|
| SWE-bench Verified | Claude Sonnet 4.5 | 77.2% | State-of-the-art as of September 2025; average of 10 trials, 82.0% with high-compute setup[4] |
| SWE-bench Verified | Claude Opus 4 | 72.5% | State-of-the-art as of May 2025[2] |
| SWE-bench Verified | Claude Sonnet 4 | 72.7% | As of May 2025[2] |
| OSWorld | Claude Sonnet 4.5 | 61.4% | Real-world computer task benchmark[4][8] |
| Terminal-bench | Claude Opus 4 | 43.2% | Terminal automation benchmark[2] |
| Sustained Performance | Claude Sonnet 4.5 | 30+ hours | Autonomous coding, building 11K-line apps[4] |
| Sustained Performance | Claude Opus 4 | 7 hours | Autonomous refactor validated by Rakuten[2] |
| Internal Code Editing | Claude Sonnet 4.5 | 0% error rate | Reduced from 9% on Sonnet 4[4] |
Industry partners have reported significant improvements in development workflows:
| Date | Version/Release | Description |
|---|---|---|
| March 2023 | Initial Claude | First Claude model released[2] |
| February 24, 2025 | Claude 3.7 Sonnet | Released with Claude Code beta research preview[1] |
| April 18, 2025 | Best Practices | Published Claude Code best practices guide[17] |
| May 22, 2025 | Claude 4 GA | Claude Opus 4 and Sonnet 4 released; Claude Code announced as Generally Available[2] |
| May 23, 2025 | Cloud Integration | Extended availability to AWS Bedrock and Google Vertex AI[5] |
| June 2025 | IDE Extensions | VS Code and JetBrains beta extensions released[2] |
| June 26, 2025 | Desktop Extensions | One-click MCP server installation for browsers[18] |
| June 30, 2025 | Hooks Support | Claude Code hooks support added[19] |
| July 4, 2025 | Subagents | Custom subagents feature released[20] |
| August 2025 | Rate Limits | New weekly rate limits introduced for Pro and Max plans[21] |
| September 29, 2025 | Claude Code 2.0 | Checkpoints, VS Code extension (GA), terminal v2.0, Claude Agent SDK released[3] |
| September 29, 2025 | Claude Sonnet 4.5 | New default model with 30+ hour autonomous operation capability[4] |
Claude Code integrates with major IDEs through dedicated extensions:
Installation is available through running Claude Code in the IDE terminal or via extension marketplaces.[3]
| Platform | Integration Type | Capabilities |
|---|---|---|
| GitHub/GitLab | Full workflow | Issues, PRs, commits, code review, @claude mentions |
| GitHub Actions | Background tasks | Automated CI/CD workflows, official Claude Code Action[24] |
| Amazon Bedrock | API Provider | Enterprise deployment |
| Google Vertex AI | API Provider | Enterprise deployment |
| GitHub Copilot | Model Integration | Claude Sonnet 4.5 available in Copilot[16] |
Claude Code supports the Model Context Protocol (MCP) for connecting to external tools and services. It can function as both an MCP server and client, enabling:
Claude Code uses a special CLAUDE.md file for persistent context and project documentation. This file can contain:[17]
The file is automatically loaded when Claude Code starts in a directory and can be placed at:
Users can create custom slash commands by placing Markdown files in the .claude/commands/ directory. These commands become available as reusable prompts within Claude Code sessions and can accept arguments.[17][25]
Recommended workflow patterns include:[17]
As of September 2025, Claude Code has several documented limitations:[5]
Known technical issues include OS detection problems in certain WSL environments and difficulties handling complex terminal UI elements.[14]
Anthropic updated its consumer privacy terms in late August–September 2025. For Claude Code when used via Free/Pro/Max consumer accounts:
Claude Code has received positive reception from the developer community. As of September 2025, it has over 5 million downloads on npm.[9] The tool has been praised for its deep codebase understanding and ability to perform complex, multi-file refactoring tasks.
Industry analysts have noted that Claude Code represents a shift from simple code completion to truly agentic development assistance. The introduction of checkpoints and autonomous operation capabilities in version 2.0 has been particularly well-received by power users who require extended coding sessions.[30]
Community resources have emerged around Claude Code, including the awesome-claude-code repository for slash-commands and guides.[31] A Claude Code CLI Cheatsheet has been published to help developers maximize their usage.[32]