How Swyngr Discovers High-Probability Swing Setups at $0 API Cost

How Swyngr delivers real-time algorithmic swing trade discovery without running up financial API bills.

One of the biggest hurdles facing independent algorithmic traders and fintech builders is the prohibitive recurring cost of real-time market data APIs. Between SIP exchanges, ticker licensing, and rate-limited queries, hosting a discovery engine can easily cost hundreds of dollars each month.

The $0/Month Architecture

Swyngr solves this by decoupling calculation from client interaction:

• Automated End-Of-Day (EOD) Ingestion: GitHub Actions runs every trading day after market close (21:00 UTC), executing a rate-limited pipeline across high-beta, liquid watchlist tickers via free Polygon.io endpoints.
• Mathematical Indicator Synthesis: We compute 20 SMA, 20 EMA, 14 RSI, standard deviation (Bollinger Bands), ATR, and Keltner Channels server-side to detect squeezes and tension scores.
• Database Persistence: Setups are normalized into Supabase daily_swings with pre-packaged candle arrays, meaning clients never make external market data requests.
• Zero Client Friction: Users explore setups and paper trade in The Arena instantly with an offline-first localStorage virtual bankroll.

Ready to test high-conviction swing setups risk-free? Launch The Arena now.