Terminal Agent

Codex CLI

OpenAI's open-source terminal coding agent — reads and edits a local repo, runs commands, and executes multi-step tasks from natural-language prompts.

Pricing

Free CLI, billed by API/token usage; bundled into ChatGPT Plus ($20/mo) and Pro ($200/mo) plans

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Codex CLI is OpenAI’s terminal-based coding agent: an open-source command-line tool that reads a local repository, plans a multi-step change, edits files, and runs commands, with approval settings ranging from step-by-step confirmation to fully autonomous runs.

Why it stands out

Terminal-first, like Claude Code. No IDE required — it runs against whatever repo is open in your working directory.
Configurable autonomy. Sandbox and approval settings scale from “ask before every command” to unattended runs for CI-style workflows.
Backed by OpenAI’s frontier models, with published benchmark results developers use to compare it against other terminal agents.

Good for

Developers already comfortable in a terminal who want an agent tied to OpenAI’s models rather than switching to a full IDE.