Diagram
← All tools

How to make and share diagrams with Codex CLI

Codex CLI (OpenAI’s coding agent in the terminal) can draw architecture diagrams, flowcharts, and sequence diagrams, but on its own they end up as text in the chat or a file only you can open. Connect Diagram once and every diagram Codex CLI makes becomes a link you can share, which stays current as the diagram changes.

Set up Codex CLI, freeHow Diagram works

1. Connect Diagram to Codex CLI

Run this in a terminal, in your repo. It connects Diagram and starts Codex CLI:

codex mcp remove diagram ; codex mcp add diagram --url https://diagram.la/mcp ; codex "Set up Diagram for this repo, then ask me what to draw. If you don't have the Diagram tools, tell me the connection didn't work."

Sign in once: Codex opens a browser tab as soon as it adds Diagram: sign in with Google and click Allow.

2. Ask for a diagram

In Codex, then describe what you want in plain words. For example:

Codex CLI draws it, keeps it in your repo’s diagrams/ folder, and gives you a link. You never have to mention Diagram again: it knows to use it.

3. Share the link

Paste it in Slack, a pull request, or a doc. Diagrams start private; add people to the project, share it with your team, or make one public. When it changes, ask Codex CLI to update it: the link stays the same and every version is kept.

Questions

Is Diagram free to use with Codex CLI?
Yes. Diagram is free for 5 projects, and there's nothing to install.
Who can see my diagrams?
Only you, until you share. Add people to a project, share it with your team through an org, or make a single diagram public so anyone with the link can open it.
What happens when the diagram changes?
Ask Codex CLI to update it. The new version lands at the same link, and every earlier version is kept.
Does Codex CLI need an API key?
No. Codex CLI signs in to Diagram with your Google account in the browser.

Diagrams in other tools