A production-ready web application for flashing firmware to ESP32/ESP8266 devices using the Web Serial API. Built for Val Town with TypeScript, React, and Hono.

• Web Serial API Integration: Flash firmware directly from the browser
• Multiple Device Support: ESP32, ESP8266, and CYD (Cheap Yellow Display) variants
• Pre-built Payloads: Bruce, ESP32 Marauder, Ghost ESP, Netagotchi
• ELF to BIN Conversion: Upload ELF files and convert them to flashable binaries
• Device Information: Read MAC address, chip features, and flash info
• Secure: Input validation, rate limiting, and CORS protection

├── backend/
│   ├── index.ts              # Main Hono server
│   ├── routes/
│   │   ├── firmware.ts       # Firmware management endpoints
│   │   ├── serial.ts         # Serial/flashing endpoints
│   │   └── static.ts         # Static file serving
│   ├── services/
│   │   ├── firmwareStore.ts  # Firmware storage and management
│   │   └── elfConverter.ts   # ELF to BIN conversion
│   └── utils/
│       └── validation.ts     # Input validation and security
├── frontend/
│   ├── index.html           # Main HTML template
│   ├── index.tsx            # React app entry point
│   ├── components/
│   │   ├── App.tsx          # Main app component
│   │   ├── ConnectPort.tsx  # Serial port connection
│   │   ├── FlashControls.tsx # Flashing interface
│   │   └── FirmwareList.tsx # Available firmware list
│   └── services/
│       ├── serialService.ts # Web Serial API wrapper
│       └── api.ts           # Backend API client
├── shared/
│   └── types.ts             # Shared TypeScript types
└── firmwares/               # Pre-built firmware binaries
    ├── bruce/
    ├── marauder/
    ├── ghost-esp/
    └── netagotchi/

1. The main entry point is backend/index.ts (HTTP trigger)
2. Frontend is served from / and API endpoints are under /api/
3. Firmware files are stored in the firmwares/ directory
4. Web Serial API requires HTTPS in production

• GET /api/firmwares - List available firmware
• GET /api/firmwares/:name - Download firmware binary
• POST /api/convert - Convert ELF to BIN
• GET /api/device-info - Get supported device information

• Chrome/Edge 89+
• Opera 75+
• Web Serial API required (HTTPS only in production)

• Input validation on all uploads
• Rate limiting on conversion endpoints
• CORS protection
• File size limits
• Malicious content scanning

The app automatically serves the frontend and handles API requests. All firmware binaries are pre-loaded and ready for flashing.