Codex Full Course: Build and Automate Anything in the Super App

Key Takeaways

• One "super app," two modes. The same application holds the regular ChatGPT chat (pulls in your existing conversations) and the Codex build environment — chat for back-and-forth, Codex for building bigger projects locally and running automations 24/7.
• Plan mode before build mode. Plan mode has Codex think through the project in depth (branding, pages, linking, scope) and ask clarifying questions before writing anything. You can switch to action/build mode afterward. The creator notes you don't always need plan mode for simple builds.
• Access levels control autonomy. "Full access" lets it run autonomously and make decisions for you (fast, less control); "ask for approval" keeps you in the loop on every change (slower, safer). Even in full access, deleting or replacing existing files still prompts for permission first.
• Effort and speed dials. Higher effort = better results but slower; lower effort = faster but less capable. A "speed mode" runs roughly 1.5× faster for demos; normal mode is about 50% slower.
• Local or cloud, with git branching. Runs execute locally by default and can switch to cloud at any time. You can fork a conversation into branches (e.g., one for design, one for the plan), and manage runs as tasks — archive, pin, or open the created files in Finder.
• Skills make it compound. Connecting plugins/skills (Gmail, presentations, social posts) lets Codex send emails, build slide decks, and run daily looped schedules — the demo builds a productized-agency website, a gamified habit-tracker prototype, and a daily Gmail-drafts automation.