Install the official package
For macOS, Linux and WSL, the official native installer is:
curl -fsSL https://claude.ai/install.sh | bashCheck PATH and EACCES without broad permission changes
Run claude --version and claude doctor. If the command is missing or EACCES appears, use the installation troubleshooting page to check PATH and the specific install directory. Avoid running the CLI as root or making whole directories world-writable.
Complete OAuth and a first session
Start claude and follow the sign-in flow for your own account. Use /login when the CLI reports an expired or missing login. Read the workspace permission prompts before allowing actions.
Claude Code · Error reference ↗ · Claude Code · Installation ↗
Frequently asked questions
Should I use sudo to fix EACCES?
Follow the official troubleshooting steps for the affected installation. Broad permission changes are not a default fix.
What if authentication is temporarily unavailable?
Check service status first; keep a working login during an incident. Use /login for explicit missing or expired credentials.