Architecture

DonFlow follows a strict zero-network, browser-only architecture. There is no backend. There is no server to compromise.

System Diagram

┌─────────────────────────────────────────────┐
│  Browser (your machine)                     │
│                                             │
│  ┌──────────┐    ┌────────────────────────┐ │
│  │ React UI │◄──►│ Dexie.js (IndexedDB)   │ │
│  └────┬─────┘    └────────────────────────┘ │
│       │                                     │
│  ┌────┴──────┐   ┌────────────────────────┐ │
│  │  SheetJS  │   │ Export Engine (JSON)    │ │
│  │ (import)  │   │ (backup / restore)     │ │
│  └───────────┘   └────────────────────────┘ │
│                                             │
│  Network requests: 0                        │
│  Server dependencies: 0                     │
│  External APIs: 0                           │
└─────────────────────────────────────────────┘

Design Principles

Zero Backend

There is no server. GitHub Pages serves pre-built static assets — it's a CDN, not a backend. The deployed bundle contains zero API keys, tokens, or endpoints.

IndexedDB as the Sole Data Store

All user data lives in IndexedDB via Dexie.js. No localStorage fallback. No cookies. No server sync.

• Data persists across browser sessions
• Close the tab — data is still there
• Clear site data — data is gone (you're in control)

Client-Side Computation

All computation happens in your browser:

• Budget calculations
• Drift detection & warnings
• What-if simulations
• CSV/XLSX parsing (via SheetJS)
• Column auto-detection from bank statements

Import Pipeline

CSV/XLSX file
    │
    ▼
SheetJS (local parsing)
    │
    ▼
Auto-detect columns (date, amount, description)
    │
    ▼
Map to internal schema
    │
    ▼
Store in IndexedDB

The entire pipeline runs in the browser. Your bank statements never leave your machine.

Tech Stack

Layer	Technology
UI	React + TypeScript
Bundler	Vite
Styling	Tailwind CSS
Storage	IndexedDB via Dexie.js
Import	SheetJS (XLSX) + PapaParse (CSV)
Hosting	GitHub Pages (static)
Components	Radix UI primitives

Verify It Yourself

1. Open DonFlow
2. Open DevTools → Network tab
3. Use DonFlow for an hour
4. Observe: zero requests after initial page load

That's the architecture. No trust required — verify it.