Codex Family Learning Map

Codex is OpenAI’s coding agent. It lives alongside ChatGPT Chat and ChatGPT Work in the same web and desktop app, plus CLI, IDE, and cloud. This page is the family map: the product tree first, then “what do I want to do?”

Docs live at learn.chatgpt.com/docs. Older developers.openai.com/codex/* URLs 308 there.

Product map

This is not “a CLI”. It is one account and several products. On 2026-07-09 the standalone Codex app merged into the ChatGPT desktop app: Chat, Work, and Codex in one window.

OpenAI coding & agent family
├── ChatGPT Chat (conversation) — questions, writing, comparing options
│   ├── Web chatgpt.com
│   ├── Desktop app (macOS / Windows; Linux preview)
│   └── Mobile (Remote continues a host session)
├── ChatGPT Work (knowledge-work agent) — finish a reviewable deliverable
│   ├── Cloud (default on the web; keeps running if you close the laptop)
│   ├── Local (desktop Work locally: files / apps on this machine)
│   ├── Scheduled tasks
│   ├── Plugins (Slack / Drive / SharePoint…)
│   └── Sites (hosted websites / internal tools, public beta)
├── Codex (coding agent) — write, debug, open a PR
│   ├── Terminal CLI         — most flexible, the CI entry
│   ├── IDE extension        — editor context, inline diffs
│   ├── Codex in the desktop app — visual diffs, PR sidebar, multi-repo
│   ├── Web chatgpt.com/codex
│   ├── Cloud                — isolated envs; GitHub / Linear / Slack
│   ├── Remote               — phone continues a connected computer
│   └── Security             — plugin + CLI/SDK + cloud scans
├── Chrome extension         — signed-in Chrome tabs for Work / Codex
└── Retired: Atlas standalone browser
    └── Officially stopped 2026-08-09; browser-agent work moved into ChatGPT / Codex

Desktop Codex is the ChatGPT desktop app Codex view — mapped on the product line and in Work vs Codex, not a second tutorial. Pets are an optional animated companion for following chat status; there is no tutorial.

One agent, one configuration model, several doors. Sandbox, approval policy, and AGENTS.md learned in the CLI apply in the IDE, desktop Codex, and Cloud. Work and Codex share usage limits.

Decision tree: what do I want to do?

What do I want to do?
├── Write / debug / refactor / open a PR
│   └── → Codex
│       ├── Terminal or CI? → CLI (`codex` / `codex exec`)
│       ├── Anchored to the file I have open? → [IDE extension](./codex-ide)
│       ├── Visual diff / PR sidebar? → Codex in the desktop app ([product line](./codex-ai))
│       ├── Away from the laptop / several parallel attempts? → [Codex Cloud](./codex-cloud)
│       ├── Phone, laptop still awake? → [Remote](./codex-remote)
│       └── Dispatch from GitHub / Linear / Slack? → Cloud + official integrations
├── Ask, write, compare, settle a design
│   └── → ChatGPT Chat (web, desktop, or mobile)
│       ├── Persistent topic context? → Project
│       ├── Hands-free? → desktop / iOS Voice
│       └── Ready to change the repo? → write the brief, hand it to Codex
├── A deck / sheet / brief / recurring update someone can open
│   └── → ChatGPT Work
│       ├── Sources in Drive / Slack? → install the plugin, `@mention` it
│       ├── Needs local files or apps? → desktop Work locally
│       ├── Must run after the laptop sleeps? → Cloud / web Work
│       └── Need a hosted internal page? → [Sites](./sites) (save a version, then deploy)
├── Find, confirm, or fix vulnerabilities in a repo I own
│   └── → [Codex Security](./codex-security) (plugin / CLI / cloud)
├── Act on a site I am already signed into in Chrome
│   └── → [Chrome extension](./codex-chrome) (`@Chrome`); localhost → `@Browser`
├── Connect an external service
│   └── → two layers
│       ├── Everyday SaaS (Drive / Slack / Notion-class) → Work / Chat plugins
│       └── Repo, CI, custom tools → Codex MCP (see Project Integration)
└── Still looking for the Atlas browser?
    └── → Standalone Atlas has stopped. Use the in-app browser, the Chrome
        extension, or Work’s cloud browser.

Concepts you need early

Full definitions live in the Glossary.

Concept	One line	Where it shows up
Chat / Work / Codex	Three ways to work in one app: talk, finish, code	Everywhere
Sandbox	Hard boundary on files and network	Codex
Approval policy	Whether it asks before acting	Codex
AGENTS.md	Project briefing loaded on every run	Every Codex surface
MCP / Plugins	Tools outside the repo; Work calls them plugins	Codex / Work
Sites	ChatGPT-hosted websites and apps (public beta)	Sites
Codex Cloud	Parallel coding jobs in a hosted environment	Cloud
IDE extension	Editor context, inline diffs	IDE
Remote	Phone steers a connected computer	Remote
Codex Security	Find / confirm / fix vulns (plugin + CLI + cloud)	Security
Chrome extension	Drive your signed-in Chrome tabs	Chrome
Atlas	Retired standalone browser; capabilities moved into ChatGPT / Codex	Historical

Learning path

Stage 1 — Tell Chat, Work, and Codex apart

Build the “one account, three modes” model before you touch the terminal.

Goal: switch Chat / Work / Codex, know what the plan includes, know where numbers live.

Step	What	Link
1	Product line: four Codex surfaces + the desktop merge	Codex Product Line
2	Plans, login, pairing Chat with Codex	ChatGPT Plans and Access
3	Work: deliverables, local vs cloud, plugins	ChatGPT Work
4	Hosted websites / internal tools (public beta)	Sites

Stage 2 — Get the CLI working

The frontend-engineer path.

Goal: a read-only run on a repo you already know, with sandbox and AGENTS.md set.

Step	What	Link
1	Install, sign in, first read-only session	Codex CLI, steps 1–3
2	TUI keys and slash commands	CLI
3	sandbox_mode and approval_policy	CLI step 6
4	/init → AGENTS.md	CLI step 7
5	Task recipes	Cookbook
6	Flags and config keys	Cheatsheet
7	Definitions when words blur	Glossary

If you only read two pages: CLI, then pin the Cheatsheet.

Stage 3 — Real project and CI

Goal: a committed AGENTS.md and .codex/config.toml; codex exec in CI.

Step	What	Link
1	Instruction chain, trust, project config	Project Integration
2	MCP, hooks, subagents	Integration
3	codex exec + GitHub Action	Integration

Stage 4 — Cloud, hosted review, remote

Goal: stand up a Cloud environment; know which model hosted review uses.

Step	What	Link
1	When to use Cloud; codex cloud exec	Codex Cloud
2	Dispatch from GitHub / Linear / Slack	Cloud · official cloud docs
3	Phone approvals on a connected host	Remote
4	Editor context and in-place review	IDE
5	Local /review vs hosted code review	Code review
6	First security scan (plugin / CLI / cloud)	Security

Stage 5 — Work automation (knowledge work)

Axis B: Work sits after the Codex path. Frontend engineers still use it for agendas, Sites, and Slack.

Step	What	Link
1	Positioning and three official starter tasks	ChatGPT Work
2	Local vs cloud, scheduled tasks	Work
3	Plugin and Sites boundaries	Work · Sites

Feature lookup

ChatGPT Chat

Feature	For	Read
Chat	Questions, drafts, settling a design	Plans and access
Projects	Chats, files, and instructions under one topic	Projects
Voice	Desktop / iOS, including files and Projects	Voice
Computer History	macOS activity timeline → memories (off by default)	Computer History
Library	Reuse saved files	Plans and access

ChatGPT Work

Feature	For	Read
Reviewable files	Decks / sheets / docs / PDFs	ChatGPT Work
Local / cloud	Local files vs keep-running	ChatGPT Work
Plugins	Drive / Slack / SharePoint…	ChatGPT Work
Sites	Hosted websites and apps (public beta)	Sites
Scheduled tasks	Recurring research, agendas, watches	ChatGPT Work
Computer Use	Operate desktop GUIs (macOS / Windows)	Computer Use
Browser	Built-in desktop browser or Work cloud browser	Browser
Chrome extension	Signed-in Chrome tabs	Chrome

Codex

Feature	For	Read
CLI	Interactive in the repo; codex exec in CI	CLI
IDE extension	Current file / selection	IDE
Desktop Codex	Diffs, PR sidebar, multi-repo, Computer Use	Product line
Web / Cloud	Hosted envs, parallelism, --attempts	Cloud
Remote	Phone steers a connected Mac / Windows host	Remote
Hosted review	Cloud code review / QA; GPT-5.6 Sol for eligible customers	Cloud
Security	Plugin workbench, CLI/SDK, Cloud scans	Security
AGENTS.md	Project briefing	Integration
MCP / Hooks / Skills / Plugins	Extension points	Glossary
Codex SDK	Programmatic local threads (TS / Python)	Codex SDK
GitHub Action	openai/codex-action@v1 runs codex exec	GitHub Action
App Server	JSON-RPC for rich clients / codex --remote	App Server
Codex Micro	Work Louder hardware keys for desktop chats	Codex Micro
Recipes	Refactors, tests, debugging	Cookbook
Config lookup	Flags, keys, decision tables	Cheatsheet

Models

As of August 2026 the recommended 5.6 family is Sol / Terra / Luna. The default Power setting is Sol at medium reasoning. Names move; Models wins.

Model	Official role	How this guide uses it
GPT-5.6 Sol	Flagship: hard coding, computer use, research, security	Cloud code review / QA selects Sol for eligible customers
GPT-5.6 Terra	Capability / cost balance	Everyday local and web work
GPT-5.6 Luna	Fastest, cheapest	Small edits, subagents, volume
GPT-5.3-Codex-Spark	ChatGPT Pro research preview	Pro only; see the pricing page

config.toml samples still say model = "gpt-5.6". The Chat-only Sol slider does not change Work or Codex. GPT-5.4 / 5.4 mini retire from ChatGPT-signed-in Codex on 2026-08-31.

Honest limits

• Read the diff and the generated file. Plausible is not correct.
• danger-full-access is named accurately. Do not use it on unread code.
• Search is cached by default. Pass bare --search for a fast-moving library.
• A Sites deploy URL is production. Save a version first.
• Details drift. Stable releases land about weekly. When this guide disagrees with learn.chatgpt.com/docs, the docs win.

Among the alternatives

If you want	Consider
A terminal / cloud agent on an OpenAI plan	Codex
The knowledge-work agent on the same plan	ChatGPT Work
The Anthropic-family counterpart	Claude Code
An editor built around AI	Cursor
Inline completion in an existing editor	GitHub Copilot

Official sources

Source	Use it for
Codex docs root	Everything
Use ChatGPT	Chat / Work / Codex
Get started with Work	Work
Codex cloud · landing	Hosted coding environments
IDE · Remote	Editor surface; phone control
Security · Sites · Chrome	Independent product landings
What's new	Weekly capability changes
Pricing	The only authority on plans and quotas
Evolving Atlas	Atlas retirement (official)
openai/codex	Source and releases

Docs pages use ?surface=cli|app|ide. If a page looks like another product, check the surface selector.