OpenAI Codex CLI
OpenAI's free, open-source terminal coding agent — runs agentic file editing, shell commands, and multi-step tasks powered by o4-mini.
Works with:chatgpt
Platform:windowsmaclinux
Articles featuring this tool
list
Best Free Terminal AI Coding Agents in 2026 (Gemini CLI Alternatives)
Gemini CLI's free tier is retiring June 18, 2026. Here are the terminal AI coding agents that are still genuinely free to run — ranked for beginners with no budget.
June 16, 2026
comparison
Claude Code vs Codex CLI vs Gemini CLI: Which Is Free?
Claude Code, Codex CLI, and Gemini CLI are all free to install — but only one is free to run. Decision tree for beginners with no IDE budget.
May 10, 2026
review
OpenAI Codex CLI Review: Free Terminal Coding Agent
OpenAI Codex CLI reviewed for beginners: setup, free tier limits, real running costs, and how it compares to Claude Code and Gemini CLI in 2026.
May 10, 2026