OpenAI Codex CLI

Name: OpenAI Codex CLI
Author: AgentRadar

Verified

OpenAI's open-source terminal coding agent

Coding Agents Freemium

8.6 /10

Visit Website GitHub

Released

2025-04

Country

United States

API

Available

Self-Host

GitHub Stars

92,000

Monthly Active Users

1M+

Funding

Private

Last Updated

2026-06

About OpenAI Codex CLI

Codex CLI is OpenAI's answer to terminal-native coding agents — an open-source, Rust-built CLI that runs locally and executes coding tasks inside a sandboxed environment. It reads and edits files, runs commands (with user approval), and uses OpenAI's reasoning models (o-series and GPT-5 class) for code generation and debugging. Codex CLI ships with any ChatGPT plan (Free, Plus, Pro, Business, Enterprise), making it the most accessible terminal agent at that tier. It supports a configurable approval workflow (suggest / auto-edit / full-auto), MCP for extending capabilities, and integrates with the ChatGPT desktop and web experience so a coding task started in chat can finish in the terminal.

Verdict

The open-source, OpenAI-powered terminal agent — and the most accessible tier-1 coding agent at the price point (free with any ChatGPT plan). If you want a sandboxed, auditable CLI that uses GPT-5 and o-series reasoning, Codex CLI is the canonical choice. Pairs naturally with Claude Code for developers who want access to both frontier families.

Features

Sandboxed command execution with approval modes

OpenAI o-series and GPT-5 model access

Open-source Rust implementation

Model Context Protocol (MCP) support

ChatGPT desktop and web integration

Multi-file editing in the terminal

Detailed Ratings

Ease of Use

8.0

Value for Money

9.0

Features

8.5

Support

8.0

Performance

9.0

Overall Rating

8.6 /10

Pros & Cons

Pros

Free with any ChatGPT plan, including the free tier — lowest barrier to entry
Open-source and auditable, written in Rust for performance
Sandboxed execution with explicit approval modes — safe by default
Deep integration with OpenAI's frontier reasoning models
Works alongside the ChatGPT web/desktop experience, not just standalone

Cons

OpenAI models only — no Claude or Gemini routing
Approval workflow adds friction for full-auto use cases
Younger than Claude Code; ecosystem of patterns and MCP servers still growing

Use Cases

Terminal-native coding with OpenAI reasoning modelsSandboxed, auditable agent execution for security-conscious teamsChatGPT users who want to extend coding tasks into the terminalOpen-source contributors who want to inspect and modify their agent

Who Is It For?

Developers who want a free, open-source terminal coding agent powered by OpenAI reasoning models

#cli#open-source#terminal#openai#sandboxed

Pricing Plans

Free

Codex CLI access
Limited monthly usage
Standard models

Plus

$20 /month

Higher rate limits
Access to more capable models
ChatGPT Plus web and mobile

Recommended

Pro

$200 /month

Highest rate limits
Frontier reasoning model access
Priority compute

Business

$25 /user/month

Team admin controls
Centralized billing
Shared workspace config

Frequently Asked Questions

Is Codex CLI really free?

Yes — it ships with any ChatGPT plan, including the free tier. Higher tiers (Plus, Pro) unlock higher rate limits and access to the most capable reasoning models.

How is Codex CLI different from Claude Code?

Both are terminal-native coding agents. Codex CLI is open-source (Rust), uses OpenAI models, and is free with ChatGPT. Claude Code is Anthropic-built, uses Claude models, and starts at $20/month. Many developers use both to access different frontier models.

What does sandboxed execution mean?

Codex CLI runs commands in an isolated environment with explicit approval modes (suggest, auto-edit, full-auto). You choose how much autonomy it has before it runs anything that affects your filesystem.