Claude Code is Anthropic's agentic coding tool that lives in your terminal. This changelog tracks all 272+ releases with new features, bug fixes, security patches, and improvements—from v0.2.21 beta to v2.1.119.
claude update. For Homebrew: brew upgrade claude-code. For WinGet: winget upgrade Anthropic.ClaudeCode. npm installation is deprecated — migrate with curl -fsSL https://claude.ai/install.sh | bash.CLAUDE_CODE_TMPDIR=/tmp/claude in your environment, or add tmpclaude-* and nul to your .gitignore.CLAUDE.md) provide persistent project context across sessions. Configure hooks in your settings.json file, and view them with /hooks.CLAUDE.md files (user-written) and auto memory (Claude-written, stored in ~/.claude/projects/<project>/memory/). You can create and edit CLAUDE.md manually, or Claude will suggest updates after understanding your project. While other .md files might appear, CLAUDE.md is the main memory file. Keep it in your project root and commit it to version control to maintain context across sessions.Ctrl+C twice to exit. If that doesn't work, force quit the terminal session. This issue occurs when there's no conversation history to resume. To prevent it, ensure you're properly exiting Claude Code using the /exit command or Ctrl+C in future sessions..gitignore patterns to exclude large files and directories from Claude Code's context. Create focused CLAUDE.md files with only essential project information — avoid verbose docs or redundant instructions. Use specific file paths instead of broad commands when possible. Start new sessions for unrelated tasks to keep context small. Using /compact will reduce current session context size./extra-usage - however this will incur extra costs/charges.CLAUDE.md files to provide project context - place them in your project root, home directory, or .claude/ folder. Define custom skills and slash commands (like /commit, /review-pr) for repetitive tasks. For external tool integration, set up MCP (Model Context Protocol) servers. Use /config to review settings and organize your project configuration for consistent behavior across your team./model <alias|name> during a session or claude --model <alias|name> at startup. For effort level, use /effort low|medium|high|max. Effort is supported on Opus 4.6 and Sonnet 4.6; max is Opus-only.CLAUDE.md file(s) for overly large project contexts, 2) Disable unused MCP servers or hooks, 3) Clear saved memories in ~/.claude/ if they become bloated. Start with a minimal configuration and add features only as needed.--enable-auto-mode at startup to make auto appear in the Shift+Tab cycle, then set it with claude --permission-mode auto for your next session. Requires a Team plan and Claude Sonnet 4.6 or Opus 4.6. If you are having issues, check whether an admin must enable auto mode in Claude Code admin settings.claude --resume or use the /resume command within Claude Code to pick a specific session to continue.ANTHROPIC_API_KEY environment variable is set correctly. Run /logout then restart Claude Code and complete authentication again. If using an API key, verify it's valid in the Anthropic Console.