codex

Launch interactive terminal UI

$ codex

$ codex "[fix the authentication bug]"

$ codex exec "[refactor this function]"

$ codex --model [gpt-5.2-codex]

$ codex --full-auto

$ codex resume --last

$ codex -i [screenshot.png] "[fix this UI bug]"

codex [options] [prompt]

Codex is OpenAI's official terminal-based coding agent. It launches into a full-screen terminal UI that can read your repository, suggest and implement code changes, and execute commands while you iterate conversationally.
The tool maintains security through OS-level sandboxing with three safety modes: read-only (consultative, no changes), auto (default, asks before touching files outside workspace), and full access (unrestricted, use with caution). Model-generated commands run in isolated environments using macOS seatbelt or Linux Landlock.
Codex integrates with ChatGPT Plus, Pro, Business, and Enterprise subscriptions, or can be used with API credits. It supports cloud tasks for offloading complex work and provides MCP integration for extended capabilities.

--model, -m MODEL

Override the default model (e.g., gpt-5.2-codex, codex-mini-latest)

Sandbox policy: read-only, workspace-write, or danger-full-access

Control approval timing: untrusted, on-failure, on-request, or never

Enable low-friction mode with on-request approvals and workspace-write sandbox

Disable approvals and sandboxing (use only in hardened environments)

Set working directory before processing

Grant additional directories write access

Attach image files to the initial prompt

Use local open-source model via Ollama

Enable web search capability

Load configuration profile from config.toml

Display help information

exec, e

Run non-interactively; supports --json, --output-last-message

Continue a previous session by ID or use --last

Branch a previous session into a new thread

Apply latest diff from Codex Cloud task to local repository

Browse or execute cloud tasks

Authenticate via ChatGPT OAuth or API key

Remove stored credentials

Manage Model Context Protocol servers (add, list, remove)

Run commands under macOS seatbelt or Linux Landlock sandboxing

Generate shell completions (bash, zsh, fish, powershell)

Requires authentication with a ChatGPT account or OpenAI API key. The --yolo flag bypasses all safety measures and should only be used in isolated environments. Network access is restricted by default; enable with --search or full-access sandbox mode.

OpenAI originally launched Codex as a code autocompletion API in August 2021, which powered GitHub Copilot. The Codex CLI terminal agent was released on April 16, 2025 under the Apache 2.0 license, with version 1.0.0 shipping in May 2025. Codex Cloud launched in June 2025 for ChatGPT Plus users. The GPT-5.2-Codex model was released in December 2025 with enhanced agentic coding capabilities.

claude(1), gemini(1), opencode(1), copilot(1)