Environment check

Works on Windows, macOS, and Linux (adjust paths if needed).

(1) Node.js

npm list -g --depth=0

• OK: output or empty list.
• Fail: “command not found” → install Node.js LTS (18+), reopen the terminal, retry.

node -v
npm -v

(2) Install CLIs

npm i -g @anthropic-ai/claude-code@latest
npm i -g @openai/codex@latest
npm i -g @google/gemini-cli@latest

Install only the tools you need.

(3) First run (creates config dirs)

Run each command once so ~/.claude, ~/.codex, and ~/.gemini are created.

claude

codex

gemini

Exit with Ctrl+C or the on-screen prompt when you see a UI or wizard.

(4) Next

With an API key:

• Claude Code
• Codex
• Gemini

Install issues

Issue	Fix
EACCES	Avoid sudo npm -g; use nvm or fix npm prefix
Corporate proxy	Set HTTPS_PROXY / npm proxy
Old version	npm i -g package@latest