diagen

Turn a spreadsheet into a finished diagram. Managers author plain Nodes and Edges rows (in Excel or CSV) — entity type, label, who's nested inside whom, who connects to whom — and the tool auto-sizes shapes, lays them out, routes the edges, and renders SVG / draw.io / HTML output. No manual drawing.

It's a FastAPI + React web app (webapp/) built on a small Python layout engine (webapp/backend/diagen/). The engine is the single source of truth for sizing, layout, and routing — the frontend is a thin client, so nothing ever drifts between what you see on screen and what gets exported.

Everything is editable interactively too: drag shapes, drag-create from a palette, connect two shapes with a click-click tool, edit labels/colors/ metadata, undo/redo, switch between diagrams in a multi-diagram workbook, paste CSV, generate from a template or an indented outline, and apply live style rules.

webapp/
  backend/    FastAPI app + the diagen engine (webapp/backend/diagen/) + bundled samples
  frontend/   Vite + React + TypeScript UI

Quick start

Backend

cd webapp/backend
pip install -r requirements.txt
uvicorn app.main:app --reload --port 8000

Frontend (separate terminal)

cd webapp/frontend
npm install
npm run dev

Open the URL Vite prints (usually http://localhost:5173).

See webapp/README.md for the full run/build guide and API reference, and webapp/backend/README.md for the engine's data format and architecture.