Configuring preloaded execution

Environment variables for controlling preloaded executor behavior in UiPath Robot.

You can manage the behavior of preloaded executors by setting specific environment variables on the robot machine. Preloaded executors exist only in User Mode, so the variables in this table have no effect in Service Mode:

Environment variable	Value	Description
UIPATH_PRE_LOADED_EXECUTOR	Legacy, Windows, Portable, or None	Sets which executors the Robot preloads: Legacy for Windows - Legacy projects, Windows for Windows projects, and Portable for cross-platform projects. To preload several, separate the values with commas, for example Windows, Legacy. The values aren't case-sensitive. None overwrites the default behavior and starts the preloaded executor only when the first job starts. If the variable isn't set, the Robot preloads Windows and Legacy on Windows, and Portable on other operating systems.
UIPATH_DISABLE_PRE_LOADED_EXECUTOR	True	Disables the preloaded executor.

Preloaded executors apply to RPA processes and test cases, which run in the Robot Executor. Agents, functions, and API workflows run in executor packages, which the variables above don't affect. The executor packages run in a separate host process, which you can preload with the following variables:

Environment variable	Value	Description
UIPATH_EXECUTORS_HOST_PRELOAD	Off (default) or On	On starts the executor hosts when the Robot connects to Orchestrator, instead of when the first job starts. In Service Mode, it has no effect when UIPATH_HEADLESS_WITH_USER is set.
UIPATH_PRELOADED_RUNTIMES	Executor package names, separated by ;, ,, or :	With preloading on, limits it to the named executor packages. If the variable is empty, the Robot preloads every executor package that the Executors feed offers.