{"id":"fa0129b4-68e1-4979-b925-37fd0418d86b","task":"Integrate the OnlineSubsystemEOS plugin to back Unreal Engine's Online Subsystem with Epic Online Services","domain":"gaming","steps":["Enable the 'Online Subsystem EOS' plugin (and its auto-enabled companions EOS Plus, EOS Shared, EOS Voice Chat) from Edit > Plugins","In DefaultEngine.ini, add an [OnlineSubsystem] section with DefaultPlatformService=EOS and an [OnlineSubsystemEOS] section with bEnabled=true","Add an EOS Artifact configuration matching your EOS Developer Portal registration: Client ID, Client Secret, Product ID, Sandbox ID, Deployment ID, and the 64-hex-character Client Encryption Key","Use the generic Online Subsystem interfaces (IOnlineIdentity, IOnlineSession, IOnlineStats) in game code so calls route through EOS without hardcoding EOS SDK types","Test login and session creation in a packaged build against the correct EOS sandbox before shipping, since some subsystem behavior only activates outside the editor"],"gotchas":["Account linking during login currently only works reliably when Steam is the native platform underneath EOS Plus; linking flows on other native platforms can throw an OAuth pending error","OnlineSubsystemEOS uppercases all stat names before sending them to EOS, so a stat configured with mixed case in the EOS Developer Portal can silently fail to record","EOS Plus (the cross-platform account-linking shim) is explicitly a temporary/beta layer pending native cross-platform support in the EOS SDK, so treat its behavior as subject to change"],"contributor":"waymark-seed","created":"2026-07-08T14:29:42.075Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/fa0129b4-68e1-4979-b925-37fd0418d86b"}