Getting started
Introduction
Nautilus is an open-source canvas for designing and explaining software architecture — components, connections, templates, a flow simulator and an optional AI assistant, all running in your browser.
What it is
A diagram in Nautilus is a graph of components and directed dependencies. That structure is what makes the rest possible: the simulator can walk it, the AI assistant can reason about it, and the exported JSON is something you can diff in a pull request.
What it deliberately isn't
There is no account, no server and no database. Diagrams live in your browser's local storage and in files you export; AI features use a key you supply and talk straight to the provider. That is what keeps Nautilus free to use, private by default and trivial to self-host.
No lock-in
Everything is plain JSON —
{ name, nodes, edges }. Export it, commit it, generate it from a script, or import it into a fork you run yourself.