About CryptoAlert
CryptoAlert is a lightweight price monitoring tool that sends you Telegram notifications the moment your conditions are met — no app switching, no dashboard refreshing.
How it works
- 1.Sign in with Telegram. Open the bot link and send it your one-time token. No passwords or email addresses required.
- 2.Build your watchlist. Search for cryptocurrencies (via CoinGecko) or US stocks (via Finnhub) and add them to your personal watchlist.
- 3.Set alerts. Choose a price threshold (e.g. BTC above $70,000) or a percentage change (e.g. ETH up more than 5% in 24 h). Configure a cooldown to avoid notification spam.
- 4.Get notified. The cron job evaluates all active alerts every few minutes and sends an HTML-formatted Telegram message the moment a condition is triggered.
Alert types
Price threshold
Fire when an asset crosses an absolute USD value — e.g. BTC above $70,000 or ETH below $2,000.
Percent change
Fire when an asset moves by a given percentage over a timeframe (1 h or 24 h) — e.g. SOL up more than 10% in the last 24 hours.
Data sources
- Crypto prices — CoinGecko public API. Prices and 1 h / 24 h change data, cached for 2 minutes.
- Stock prices — Finnhub API. Real-time quotes for US equities, cached for 2 minutes.
- Notifications — Telegram Bot API. Messages are delivered directly to your Telegram account.
Tech stack
- Framework — Next.js 16 (App Router) with React 19
- Database — Supabase (PostgreSQL) with row-level security
- Auth — Telegram-based, httpOnly JWT session cookie
- UI — Tailwind CSS 4 + shadcn/ui