Steam Authentication

Let Steam check every player who joins your hosted game: the player really is who they say, owns your game, and has no VAC or publisher ban. Unreal does the check; Sandwich Steam turns it on and tells you the result.

1. Turn it on
2. What happens to a player who fails?
3. Blueprint nodes
4. Good to know

Turn it on

1. Open Project Settings > Plugins > Sandwich Steam - Auth and tick Enable Steam Authentication. (The same switch is on the Steam Dashboard’s Advanced page, card Steam authentication.)
2. In the Steam Dashboard click Configure Steam… and apply. It adds one line to DefaultEngine.ini.
3. Restart the editor, then package or launch again.

That is all. The Validate Project check and the Advanced page card tell you if the setting and the ini line do not match.

Host and players need the same setting. If one build has it and the other does not, the player never gets in (the connection keeps retrying). Ship one build and this never happens.

What happens to a player who fails?

Choose the Failure Policy next to the switch:

Policy	What happens
Kick (default)	Unreal kicks the player. You still get the result event with the reason.
Custom	Nobody is kicked. The event On Steam Auth Failed fires and your game decides, for example with the Kick Steam Player node.

Blueprint nodes

The events live on the Steam Auth Subsystem (Get Game Instance Subsystem > Steam Auth Subsystem, then Bind Event to On Steam Auth Result). They fire on the host only, a moment after the player logged in.

Node	What it does
On Steam Auth Result	Steam answered for a joining player: Success and the reason (OK, No Ownership, VAC Banned…)
On Steam Auth Failed	Custom policy only: a player failed and was not kicked
Get Steam Auth Status	Not Checked, Pending, Passed or Failed
Is Player Steam Authenticated	True when Steam accepted the player. The host’s own players always count
Kick Steam Player	Kicks a player with a reason (host only)
Is Steam Auth Active	True when the check is really running

Want a “verified” badge on other players’ screens? Clients do not get the results. Store the result in a replicated variable on your Player State from the host’s On Steam Auth Result.

Good to know

• It is not anti-cheat. VAC only reports bans that already exist.
• Testing needs two PCs and two Steam accounts. To see a failure you need your own App ID: everybody owns the test app Spacewar (480).
• Without Steam (Play In Editor, LAN) nothing is checked and players still connect.
• Not the same as the Web API ticket (Get Steam Web API Ticket). That one is for logging in to your own server.
• Dedicated servers are not supported yet.
• Console: Steam.Auth.Dump prints the setting, the policy and every player’s status.