API Integration

Overview

The Crypto Price Alarm integrates with external APIs to fetch real-time cryptocurrency price data and to deliver notifications. This section documents the data source, the streaming and fallback mechanisms, and the resilience behavior.

Binance: Primary Data Source

All price data is sourced from Binance’s public market-data API, which provides:

No Authentication: No API keys required, only unauthenticated market-data endpoints are used
Comprehensive Coverage: Every spot trading pair Binance lists
Real-Time Data: A WebSocket ticker stream pushes updates as trades happen
Free: The WebSocket stream does not count against REST request weight

Key Topics

Streaming Architecture

One combined WebSocket stream for all monitored pairs
Automatic reconnect with backoff
The stream is re-opened when the set of pairs changes

Price Data

24-hour ticker: last price, 24h change, 24h high and low
No ratio calculations: every pair is a native Binance symbol, so ETHBTC is the exchange’s own price
Base and quote assets come from Binance’s exchangeInfo

History Backfill

Hourly and 5-minute candles download when a pair is added and at startup
Enables timeframe alarms of up to 7 days immediately

Rate Limiting & Resilience

REST fallback when the stream is silent
Retry-After handling for HTTP 418 / 429
Isolation of delisted symbols
A health endpoint and a status badge in the UI

Notification APIs

ntfy, Telegram and webhook delivery with retries and duplicate suppression

Next Steps

Dive into the Binance Integration documentation for complete implementation details.