FTMS (Fitness Machine Service) is the open Bluetooth standard smart trainers use to report power and accept resistance commands. If your trainer is from the last several years, it speaks FTMS.
Monsoon Cycles, Colorado Springs · Updated August 16, 2026
When Gumwall Grand Prix connects to your smart trainer it reads the Indoor Bike Data stream (power, cadence, speed) and writes to the control point: when the road tilts up, the game sends your trainer the new gradient and pedaling gets harder. That is the entire magic of every smart trainer app, and it is an open standard, which is why a free browser game can do it.
Older trainers sometimes speak proprietary Bluetooth dialects instead (the early Tacx FE-C-over-BLE era); support for those quirk-by-quirk is on the roadmap as real hardware reaches the shop.
Almost everything sold since about 2018 does. If Zwift connects to it over Bluetooth as a controllable trainer, FTMS will almost certainly work here too.
Web Bluetooth, the browser API that talks to sensors, ships in Chromium browsers. Firefox and Safari have chosen not to implement it.