This article covers the following platforms
MSFS 2024
MSFS 2020
ATS
FSX
Prepar3D
Flow scripts run inside Coherent GT, the platform Microsoft Flight Simulator uses to build its user interface with HTML, CSS, and JavaScript.
Version
The most recent Coherent GT release came out in 2016 and includes the Chrome browser from that year, version 49.0.2623. To see which modern web features it lacks, compare Chrome 49 with a current version on Can I use.
The User Agent of the sim’s UI is "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/604.1.38 (KHTML, like Gecko) Chrome/49.0.2623 Safari/604.1.38 CoherentGT/2.0"
What doesn’t work
Debugging
The Flow code editor includes a console for basic debugging.
For more detail, open http://127.0.0.1:19999 in your browser, or run the Coherent GT Debugger that comes with the MSFS SDK (SDK\Tools\CoherentGT Debugger\Debugger.exe) and select //42 Flow from the list.