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Codex CLI

TOOL

OpenAI's lightweight coding agent that runs in your terminal. Code generation, file editing, and command execution with approval. Apache 2.0 licensed

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Overview

Free tool — Codex CLI. OpenAI's lightweight coding agent that runs in your terminal. Code generation, file editing, and command execution with approval. Apache 2.0 licensed

What this tool does

Reach for "Codex CLI" whenever you need a reliable tool for real work across ChatGPT, Claude, Gemini, and Cursor. OpenAI's lightweight coding agent that runs in your terminal. Code generation, file editing, and command execution with approval. Apache 2.0 licensed OpenRuna cross-links it to related prompts, agents, and tools, which makes assembling a full workflow around it straightforward. Open a new conversation and paste it in, wire it into an agent, or keep it in your team's prompt library.

Use cases

  • Combine it with related tools and prompts in the same OpenRuna category to build an end-to-end workflow.
  • Reach for it during planning or review sessions when you want consistent, AI-assisted structure.
  • Use "Codex CLI" when you need a repeatable tool for professional work without rewriting instructions every time.
  • Hand "Codex CLI" to a new teammate so their tool output matches your team's quality bar from day one.

Example output

Ask the model to apply "Codex CLI" to your scenario and it returns a structured answer — clear sections, actionable steps, and assumptions stated upfront — ready to paste into docs, tickets, or code comments. Expect 2–3 iterations to dial in tone and depth for your context.

Tips by platform

Claude

In Claude, paste the full tool as your first message or add it to Project instructions, then ask Claude to confirm assumptions before it executes. For longer tools, iterate inside the artifact panel.

ChatGPT

In ChatGPT, start a fresh chat and paste this tool verbatim, then follow up with "apply this to [your context]." Pick a current GPT model for coding or reasoning tasks.

Cursor

Add this tool to your Cursor rules and invoke it from Agent mode for repeatable results. Link back to its OpenRuna page in the rule so the source stays discoverable.

Frequently asked questions

What is "Codex CLI"?
It is a tool listed on OpenRuna — OpenAI's lightweight coding agent that runs in your terminal. Code generation, file editing, and command execution with approval. Apache 2.0 licensed You can copy and adapt it for ChatGPT, Claude, Cursor, or any other AI assistant.
Is "Codex CLI" free to use?
Most OpenRuna resources are open or CC0-licensed. Check the license shown on this page before commercial use; premium collections are clearly marked as such.
How do I get the best results from this tool?
Replace any placeholders, add your project context, and ask the model to confirm its assumptions first. Iterate over 2–3 follow-up turns rather than expecting a perfect first response.
Does "Codex CLI" work with both Claude and ChatGPT?
Yes — it is model-agnostic text, so it runs on Claude, ChatGPT, Gemini, and Cursor. The tips on this page cover each of those assistants specifically.
Where can I find resources related to "Codex CLI"?
Scroll to the Related resources section on this page, or open the matching category hub on OpenRuna to find connected prompts, tools, agents, and datasets in the same topic area.

Related resources