Codex clearly explained (and how to use it)
The Startup Ideas Podcast
Intro
Greg Isenberg sets up a skeptical but practical tour of Codex, promising tips on skills, Notion, Remotion, and GPT 5.5 workflows.
I sit down with Riley Brown to get a hands-on tour of OpenAI's Codex, which he argues is the most powerful single interface for using AI agents today. Riley walks me through how Codex unifies vibe coding, knowledge work, browser use, computer use, and automations into one app, all running on GPT 5.5. I come in as a complete Codex skeptic who has spent most of my time in Claude Code, and Riley shows me skills, plugins, projects, Remotion, Chronicle, and the in-app browser to make his case. By the end, the question becomes whether the era of separate tools for documents, decks, code, and research is collapsing into a single super app.
00:00 – Intro
03:23 – What is Codex
06:46 – Why a GUI beats the terminal for most users
10:13 – Codex: the all in one platform
12:48 – Atlas browser inside Codex
14:21 – Remotion explained and motion graphics workflows
19:28 – Computer use and Chronicle
22:26 – Plugins, skills, MCPs, and integrations
31:57 – Evals, examples, and good outpu
38:43 – Hard questions: who Codex is built for
40:44 – Browser use plays itself in chess
43:20 – Running Claude Code inside Codex
45:58 – GPT 5.5 cost and effort settings
48:50 – GPT Images 2.0
54:09 – Why most people feel overwhelmed by AI tools
57:09 – Three projects to start with on day one and Closing thoughts
Key Points
Codex is positioned as a super app where coding, documents, decks, research, and automations live in one interface, with GPT 5.5 as the underlying model.
The trend across Codex, Cursor, and the Claude Code desktop app is the same GUI pattern: chats on the left, agent in the middle, output on the right.
Plugins offer official integrations like Slack, Notion, Sheets, Remotion, and Canva, while skills are user-created instructions stored as a SKILL.md file.
Computer use and browser use have crossed a speed threshold; the chess demo runs at near-human pace, a leap from earlier "dial-up" feeling agents.
Running Claude Code inside the Codex terminal lets you stack both subscriptions and use each model where it shines.
The biggest unlock for companies is collecting good examples of finished work so agents can match the bar.
The #1 tool to find startup ideas/trends - https://www.ideabrowser.com
LCA helps Fortune 500s and fast-growing startups build their future - from Warner Music to Fortnite to Dropbox. We turn 'what if' into reality with AI, apps, and next-gen products https://latecheckout.agency/
The Vibe Marketer - Resources for people into vibe marketing/marketing with AI: https://www.thevibemarketer.com/
FIND ME ON SOCIAL
X/Twitter: https://twitter.com/gregisenberg
Instagram: https://instagram.com/gregisenberg/
LinkedIn: https://www.linkedin.com/in/gisenberg/
FIND RILEY ON SOCIAL
X/Twitter: https://x.com/rileybrown
Vibe Code App: https://www.vibecodeapp.com
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