GM.setValue

Description

This method allows user script authors to persist simple values across page loads and across origins.

Strings, booleans, and integers are currently the only allowed data types.

function GM.setValue( name, value )

name: String The unique (within this script) name for this value. Should be restricted to valid Javascript identifier characters.
value: String, Integer or Boolean Any valid value of these types. Any other type may cause undefined behavior, including crashes.

A Promise, resolved successfully with no value on success, rejected with no value on failure.

Set the name foo to hold the value bar:

GM.setValue("foo", "bar");