How to make and share diagrams with Gemini CLI
Gemini CLI (Google’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 Gemini CLI makes becomes a link you can share, which stays current as the diagram changes.
1. Connect Diagram to Gemini CLI
Run this in a terminal, in your repo. It connects Diagram and starts Gemini CLI:
gemini mcp remove -s user diagram ; gemini mcp add -s user --transport http diagram https://diagram.la/mcp ; gemini -i "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: When Gemini first connects, a browser tab opens: sign in with Google and click Allow.
2. Ask for a diagram
In Gemini CLI, then describe what you want in plain words. For example:
- “Draw how a request flows through this app, from the browser to the database.”
- “Make an architecture diagram of this repo and give me a link I can share.”
- “Diagram the checkout flow, then update it after we add the fraud check.”
- “Show the data model as an entity diagram.”
Gemini 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 Gemini CLI to update it: the link stays the same and every version is kept.
Questions
- Is Diagram free to use with Gemini 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 Gemini CLI to update it. The new version lands at the same link, and every earlier version is kept.
- Does Gemini CLI need an API key?
- No. Gemini CLI signs in to Diagram with your Google account in the browser.