Get your Codex prototype reviewed, right on the page.

You built it fast in Codex. Crux puts a toolbar on the running prototype, so your team can comment on any part, approve it, and see the research behind it.

Add Crux to your Codex prototype

Paste one command in your prototype’s folder.

  1. 1

    Start free

    Create a Crux account. It comes with a project for your prototype.

    Start free
  2. 2

    Paste it into Codex

    Paste one command in your prototype’s folder. Codex adds Crux, signs in with you, and adds the connector.

    Run in the prototype’s folder

    codex mcp add crux --url https://mcp.crux-hq.com/mcp; codex mcp login crux; codex 'Install the Crux connector on this prototype, for my Crux project: find it with listing_projects on the crux MCP server, and ask me which one if there are several. Call prototype_plan on the crux MCP server first and follow its steps. If this folder has no prototype yet, build it from the plan, then install. If it has one, keep it as it is and link it to the plan. Either way finish with install_proof and make every change it lists, committed so deploys carry it. If the crux tools are not available, tell me to run /mcp, pick crux and sign in, then carry on.'

  3. 3

    Review on the prototype

    Reload the prototype and sign in on the Crux button at the bottom left. Click Inspect, then any part of the page, to comment on it or approve it.

On the prototype

The Crux connector adds one toolbar to any prototype.

  • See why

    Click a part of the page to see the finding and the quotes behind it.

  • Comment

    Talk it through on the component, with labels, @mentions and replies.

  • Approve

    Sign off UX, UI, functionality and content, page by page and piece by piece.

Questions

What does Crux change in my Codex prototype?
It adds a small tag to each page and component, so a comment stays on the part it is about, and one script that loads the toolbar. Codex makes the changes in your code, where you can read them before you publish.
Do my reviewers need Codex?
No. They open the prototype’s link in any browser, on a computer or a phone, and sign in on the Crux button. Reviewers, approvers and viewers take part free.
Is it free?
The connector is on every plan, Free included, so you can inspect, comment and approve on your own prototype at no cost. Inviting other people starts with Starter, at $29 a month.
What happens when the prototype changes?
Crux follows it. When you open the prototype, Crux picks up new and changed pages and components. Comments and approvals stay on the part they were made on, because each part has its own id in the code.

More ways in

Build anywhere.Think in Crux.

Evidence behind every decision, in every tool you build with.