Codex Sites Clearly Explained (and how to use it)

Codex Sites is designed as an internal tool builder rather than a public deployment platform, which means it ships without built-in authentication, databases, or payment handling, and currently cannot publish to a custom domain or deploy publicly beyond internal team sharing. Public domain deployment is expected soon, and access for Plus users is also anticipated, as not everyone has it yet.

Compared to Replit, Lovable, and Bolt, which offer one-prompt creation with built-in editors, databases, servers, and hosting, Codex Sites requires more deliberate setup. It functions as a plugin invoked via at-sites within the Codex interface, and without explicitly prompting it to handle memory and use a database, any app built with it operates only as a demo with no data persistence. Codex Sites uses Cloudflare D1 as its durable storage layer, and many users are beginning to pair it with Convex as an alternative database solution.

The episode demonstrates building a kanban-style board with columns labeled inbox, researching, validating, building, and killed, constructed in approximately six prompts. The data model includes fields for idea content, current column, and owner email, with actions covering list, add, update, move, score, archive, and seed. Asking Codex to display the data model and required actions before writing any code helps non-technical users identify which operations to create first, with add idea and update idea highlighted as the most valuable starting points.

Safe actions are approved buttons through which agents can automate adding, removing, and editing content without requiring manual human input at each step. Skills are reusable instruction manuals that teach Codex how to operate a specific app in future sessions, and they are required in order to use safe actions at all. The speaker created a skill called Startup Ideas Admin to teach future chats how to read the board, add ideas, and move cards, then tested the full loop by opening a new chat, invoking the skill, and having Codex autonomously add an AI agent SEO grader for local businesses as a new inbox card without any manual editing involved.

Codex Sites supports a range of plugins including Figma, Canva, HeyGen, Remotion, Game Studio, FAL AI, and Hugging Face open source models. Building games through these plugins is described as a way to generate buzz and funnel users into a core product. The speaker also noted that Codex Sites can enable autonomous updates to personal websites, citing their own newsletter at 158,000 readers as a case where subscriber counts currently require manual site edits each time the number changes, a task that autonomous operation could eliminate.

The speaker frames the real unlock of Codex Sites as creating products that Codex can keep operating autonomously over time, rather than using it simply to produce static web pages. The prediction is that agents automatically updating and operating apps will become a growing trend, and that Codex Sites is currently leading in that direction.