The questions people ask first

Does C4Stage need access to my code or my repository?

No. C4Stage never connects to a repository and never receives source code. When your own AI draws a canvas, it reads the code on your machine and sends C4Stage only the drawing: nodes, edges, flows, tags and health URLs. The built-in assistant sees only what you type and what is already on the canvas.

What is the C4 model?

A way of drawing software at zoom levels: context (the people and systems around your software), containers (the deployable things inside it), components (the parts inside those) and code. C4Stage puts the first three on one canvas, so you expand a box instead of opening another diagram.

How does live health work, and is it safe?

You give a service the URL of its health endpoint. Our servers request it with a plain GET on a short timeout; a 2xx answer means healthy. Only public addresses are accepted, redirects are not followed, and the URL and its response are never shown to other visitors. The security page has the details.

What counts as an AI action?

One message to the assistant, or one call from your own AI that changes a canvas (creating it, or applying changes). Reading a canvas over MCP is free. The trial includes 20 a month, Pro 300, and Studio is unlimited within fair use.

Who needs a paid plan?

The person who owns the canvases. Canvas, flow, collaborator and presentation limits run on the owner's plan, so the people you invite only need a free account. Each person's AI actions count against their own account.

What happens when the free trial ends?

Your canvases go read-only, for you and for everyone you shared them with, until you pick a plan. Nothing is deleted, and upgrading reopens everything exactly as it was.

Can I bring the diagrams I already have?

Paste Mermaid, a flowchart or a C4 diagram, and the canvas rebuilds it with its boundaries and labels. Export goes the other way too: Mermaid for the repository, and PNG, SVG or PDF for everything else.

Can people watch a presentation without an account?

Yes. Present creates a link; viewers follow your selection, filters and flow playback live, with no account. Share links give the same read-only, no-account access to a canvas at rest.

See also the pricing page, the security page and the user manual.