Inside Codex Sites: Full Tutorial Before Public Launch

TL;DR

• 1

  Codex Sites is strongest when the app keeps operating after you build it: Greg's main takeaway is autonomous product building, where a site can keep updating content, records, and workflows without you manually editing every page.

• 2

  It is more technical than Replit or Lovable, but that tradeoff buys more control: He says Replit and Lovable are better for all-in-one simplicity, while Codex Sites currently lacks built-in payments, email, analytics, secret vaults, and easy public custom domains.

• 3

  The first practical rule is to ask for memory and persistence explicitly: In his demo, he prompts Codex to show the data model first, then stores ideas in Cloudflare D1 so the board survives between visits instead of acting like a disposable demo.

• 4

  Safe actions are the key mechanism for letting Codex operate the app safely later: He creates named actions like add idea and update idea so future chats can mutate the app through approved routes instead of raw SQL or arbitrary database writes.

• 5

  Skills turn your app into something Codex can reliably use across future chats: Greg creates a skill called "startup ideas admin" that explains how to read the board, move cards, score ideas, and includes five example commands.

• 6

  His 'wow moment' is proving the loop in a new chat: After saving a review checkpoint, he opens a fresh thread, asks Codex to use the skill to add "AI agent SEO creator for local businesses," and watches it write to the live board through the safe API.