Codex CLI is OpenAI's open-source coding agent for the terminal. It edits files, runs commands in a sandbox with configurable approval modes, and can hand longer tasks off to Codex cloud to run in the background. Usage is included with ChatGPT Plus/Pro plans, making it the default choice for developers already in the OpenAI ecosystem.
Bars show editorial scores from hands-on testing. Percentages showCodex's live community win rate in head-to-head votes.
Runs on: macOS · Linux · Windows (terminal) · Codex cloud|Best for: ChatGPT subscribers who want a capable terminal agent at no extra cost
OpenAI Codex CLI takes a custom OpenAI-compatible base URL. Point it at Standard Compute and get unlimited LLM compute at one flat monthly price — no rate limits, no per-token billing.
The CLI itself is open source and free. Model usage is included with ChatGPT Plus ($20/mo) and Pro plans, or billed per token via API key. For ChatGPT subscribers it's effectively a no-extra-cost coding agent.
Terminal coding tasks for developers already paying for ChatGPT: multi-file edits, sandboxed command execution, and longer tasks handed off to run in Codex cloud. It's the strongest answer to 'I have ChatGPT Plus — what agent should I use?'
These are the two flagship terminal agents of 2026. Claude Code generally edges output quality and agentic depth; Codex wins on bundled value if you already subscribe to ChatGPT. Most head-to-head preferences come down to which model family you rate higher — vote on the matchup to add yours.
