Codex CLI
- Category
- Terminal AI Coding Agent
- Platform
- macOS, Windows, Linux
- Pricing
- Included with ChatGPT Plus ($20/mo) / Pro / Team
- License
- Apache 2.0 (Rust)
- Context File
- AGENTS.md
- Key Features
- Sandbox default, goal mode, MCP, codex exec for CI
Codex CLI is OpenAI's answer to Claude Code — a terminal-native agent that reads your repo, runs commands in a sandbox, and ships multi-file changes. Open-sourced in 2025, it's the natural pick for teams already on ChatGPT Plus who want agentic coding without a separate subscription.
Sandbox-First by Design
Every shell command runs through Landlock + seccomp sandboxing by default. That makes Codex CLI safer for autonomous runs on sensitive codebases — a meaningful difference from agents that execute freely until you configure restrictions.
Goal Mode & Cloud Handoff
- Goal mode — describe outcomes, not steps; the agent plans the path
- Appshots — visual context from running apps for UI work
- codex exec — headless mode for CI/CD pipelines
- MCP — connect GitHub, filesystem, and custom servers
- Local models — run via Ollama for air-gapped workflows
When to Pick Codex Over Claude Code
Choose Codex if you're on ChatGPT Plus already, need sandbox-by-default for compliance, or want open-source auditability. Choose Claude Code for harder reasoning tasks, richer subagent workflows, and the deepest MCP + hooks ecosystem.