Steam browser protocol From Valve Developer Community Jump to: navigation , search There are numerous system-wide commands available that interact with Steam . All of them open up Steam if it is not open. They can either be typed into a command box (Start-> Run) or through your browser's address bar (you can normally create links to them as you would web page links). Use a Steam Application ID in place of <id> (i.e. 211 for the Source SDK). Implemented commands steam:"<commands>" Opens Steam with command line arguments, which can be found here . Note: If you forget the closing quote on a steam:"<command>", you will get an assertion failed error from Steam.exe/BootStrapperApp.cpp. steam://AddNonSteamGame steam://advertise/<id> Opens up the store for an application. steam://ackMessage/ackGuestPass/<pass> Accepts the Gift or Guest Pass. steam://appnews/<...