# Tankfern (by CyberMax)
> Degree-day delivery planner and K-factor tool for small heating-oil and propane dealers, HVAC service firms and facility energy managers. For each customer tank: gallons used since the last fill (heating degree days since the fill / K-factor + daily hot-water load), % full now, projected run-out and deliver-by dates, and a delivery list sorted by urgency (this week / next week / later) that prints as a route sheet. Live degree days from NOAA Regional Climate Centers (ACIS); weekly residential heating oil and propane prices from the U.S. EIA. Planning estimates only; always check the tank gauge.

- App: https://tankfern.cybermaxtools.com/
- Free: up to 10 customer tanks, live degree days for 1 station, forecasts and the route sheet. No account; data stays in your browser.
- Pro monthly: $29 per month https://tankfern.cybermaxtools.com/buy/pro-monthly?s=llms
- Pro yearly: $290 per year https://tankfern.cybermaxtools.com/buy/pro-yearly?s=llms
- Pro lifetime: $449 one-time https://tankfern.cybermaxtools.com/buy/pro-lifetime?s=llms
- Pro adds unlimited tanks, several stations, CSV import/export, learned K-factors, price alerts and route sheets with totals.
- Public data endpoints (JSON, CORS): https://tankfern.cybermaxtools.com/api/hdd?sid=EWR&start=YYYY-MM-DD&end=YYYY-MM-DD&base=65 · https://tankfern.cybermaxtools.com/api/stations?state=NJ · https://tankfern.cybermaxtools.com/api/prices
- Machine-readable pricing: https://tankfern.cybermaxtools.com/pricing.json