Tomato — Visual DAG editor for NixOS configurations

Visual hierarchical DAG editor that generates configuration.nix or flake.nix and deploys to a real NixOS machine via SSH with one click.
Nodes are Nix fragments. Gateways descend into subgraphs (floors). NixOS merges the composed fragments automatically.

What's inside:

• Traditional configuration.nix and full Flake backend (toggle in the UI)
• Multi-machine flakes — each machine is a gateway with its own subgraph
• Home Manager support alongside NixOS configs OODN registry for ambient config (${hostname}, ${timezone}, ${pg_port}...) — change once, updates everywhere
• Deploy modes: Switch / Test / Dry Run / Diff / Rollback — all from the UI
• Pre-built stacks: Prometheus, Grafana+Prometheus, Web Server, and more
• Undo/Redo, node search, minimap, content preview on canvas
• Built with Elixir/Phoenix LiveView

Early stage but working end-to-end on a real NixOS machine.
Comments, ideas, and improvement requests very welcome.
GitHub: Tomato