Tapedeck, the backtester that refuses to flatter you

Field notes

The engine replays strategies through an onBar callback and can be run from the browser or with a command such as tapedeck run strategy.ts --data btcusdt-1h.tape. Its sample output keeps caveats visible: 139 sub-bar latency orders were ignored, while the BTCUSDT example reports 8,332.60 USDT before costs, 6,027.20 USDT in commission, and 2,305.40 USDT net. The page also compares the same crossover across Binance and Coinbase fee schedules.