sunwatch

Crypto-paid uptime monitoring for builders.

Try the hosted version: https://sunwatch.sunfamily.xyz
Build log: How I built a no-KYC, crypto-paid uptime monitor on Base

sunwatch is a tiny, wallet-to-wallet uptime monitor. Add a URL, send the exact USDC amount shown on Base, and your monitor auto-activates. No accounts, no KYC, no monthly SaaS subscription—just a webhook when your site goes down or comes back up.

Why it exists

Side projects and small services need uptime alerts, but most monitoring tools want a credit card, a long-term subscription, and a dashboard login. sunwatch flips that: you pay per monitor with stablecoins, wallet-to-wallet, and you get simple JSON webhook alerts.

How the crypto-paid flow works

1. Create a monitor at /dashboard. Enter the URL, expected HTTP status, response-time threshold, and a webhook URL.
2. sunwatch shows a unique exact payment amount (e.g. 1.000042 USDC). The small unique identifier lets us link your payment to the monitor.
3. Send exactly that amount in USDC on Base to the receiving wallet.
4. The payment poller watches on-chain transfers. Once it confirms your exact amount, the monitor activates automatically for 30 days.

Pricing: $1 / monitor / month, paid wallet-to-wallet in USDC on Base.

Receiving wallet (Base): 0x1e2D7F8715E8180816c0236A5c4F21596C5b9c9e

Stack

• Node.js >= 20
• SQLite (better-sqlite3, WAL mode)
• Express web server
• viem for Base on-chain payment verification
• node-cron pinger + payment poller
• systemd services on a small VPS
• HTTPS via Caddy + Let's Encrypt on the hosted instance

Self-host

git clone https://github.com/ryan-knowone/sunwatch.git
cd sunwatch
npm install

Set environment variables:

export PORT=3001
export SUNWATCH_DB=/var/lib/sunwatch/sunwatch.db
export RECEIVING_WALLET=0x1e2D7F8715E8180816c0236A5c4F21596C5b9c9e
export BASE_RPC=https://mainnet.base.org

Run migrations:

npm run migrate

Start the server and pinger:

npm start        # API + dashboard
npm run pinger   # checks every minute

For production, put a reverse proxy (Caddy, Nginx, etc.) in front for HTTPS and run the processes as systemd services.

systemd services

Sample unit files are included in systemd/. Copy and edit them for your user/paths:

sudo cp systemd/sunwatch-server.service /etc/systemd/system/
sudo cp systemd/sunwatch-pinger.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now sunwatch-server sunwatch-pinger

Webhook alert format

When a monitor changes state (up → down or down → up), sunwatch POSTs a JSON body to the monitor's webhook_url:

{
  "monitor_id": 1,
  "url": "https://example.com",
  "state": "down",
  "status_code": 500,
  "response_ms": 245,
  "error": null,
  "timestamp": "2026-07-03T12:34:56.789Z"
}

• state is "up" or "down".
• status_code is the HTTP response status (or null if the request failed).
• response_ms is the total request time.
• error contains an error message when the request could not complete.

Try it

The fastest way to see sunwatch in action is the hosted version:

👉 https://sunwatch.sunfamily.xyz

Create your first monitor, send the exact USDC amount on Base, and watch it activate.

License

MIT