Rockstar Launcher?

[TheMickeyMoose]

Do I need to install the Rockstar Launcher to play this or will it just run while the games playing?

[BippoErnesti]

When you first launch the game, Steam installs the Rockstar Games Launcher, after which you'll have to log in to (or create) a Rockstar Games account. If you set the launcher to remember your login, subsequent launches of the game through Steam should automatically boot up the launcher, followed by the game soon after. While the game's running, RGL will also be in the background, meaning you'll have its in-game overlay, though it usually only pops up notifications on game launch and when you get an achievement. Quitting the game closes the launcher.