the JSON the engine runs; edit it or pick a template above
The engine validates it and renders exactly what it will do.
Backtest firstReal history from Alpaca or Twelve Data, same engine as live (Finnhub's free plan streams but has no history).
Welcome
Paste an API key and connect. Click any summary on the left to open its detail here.
No key yet? Sign in under Settings, then make a key under API keys. What you see now is the empty Sandbox; books, trades and signals fill it once a key is connected.
No backtest yet
Pick a template or paste a strategy, choose a symbol and a span, and press Run backtest.
History is fetched with your connected data key: Alpaca or Twelve Data. Finnhub streams live bars but has no free candle history.
Bar size follows the span unless you choose one: 1-minute up to 2 days, 5-minute to 10, 15-minute to 45, hourly beyond.
Fills happen on the bar after the signal, costs are always adverse, and a bar that touches both stop and target resolves to the stop and is flagged. The same rules a live book lives by.
ClipboardA scratch area for keys, run ids, strategy JSON, notes. Stays in this browser only; nothing is sent anywhere.