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sneak 8be7002ad9 Fix latency measurement and chart direction - Use Resource Timing API for accurate network latency instead of performance.now() around fetch (fixes ~600ms measurement error) - Chart now shows latest sample at right edge, growing left - Reduce request timeout from 5000ms to 1000ms		2026-01-30 22:23:35 -08:00
src	Fix latency measurement and chart direction	2026-01-30 22:23:35 -08:00
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NetWatch

Real-time network latency monitor SPA designed to be served from a static bucket.

Features

Real-time monitoring: Updates every 250ms
10 monitored hosts: Google Cloud, AWS, GitHub, Cloudflare, Azure, DigitalOcean, Fastly, Akamai, local gateway (192.168.100.1), and datavi.be
Visual latency display: Large color-coded latency figures (NNNms format)
Sparkline graphs: 300-second history visualization for each host
Color coding:
- Green: <50ms (excellent)
- Lime: <100ms (good)
- Yellow: <200ms (moderate)
- Orange: <500ms (poor)
- Red: >500ms (bad)
- Gray: offline/unreachable
Zero runtime dependencies: All resources bundled into build artifacts
IPv4 only: Designed for IPv4 connectivity testing

Latency measured via HEAD requests with cache-busting
Uses mode: 'no-cors' to allow cross-origin requests where CORS headers aren't present
5-second timeout for unresponsive hosts
Canvas-based sparkline rendering
Tailwind CSS v4 for styling

# Install dependencies
yarn install

# Development server
yarn dev

# Production build
yarn build

# Preview production build
yarn preview

After running yarn build, deploy the contents of the dist/ directory to any static file host:

dist/
├── index.html
└── assets/
    ├── index-*.css
    └── index-*.js

All assets are bundled and minified. No external dependencies at runtime.

Requires modern browser with:

CORS: Some hosts may block cross-origin HEAD requests. The app uses no-cors mode which allows the request but provides opaque responses. Latency is still measurable based on request timing.
Local gateway: The 192.168.100.1 endpoint requires the host to be accessible from your network.
Network conditions: Measurements reflect browser-to-endpoint latency, which includes your local network, ISP, and internet routing.

MIT