Functions

Overview

All nodes are async Blueprint actions — they return immediately and fire their output pins when the operation completes (via EOS server callbacks). You connect your logic to OnSuccess and OnFailure pins exactly like other async Unreal nodes.

Core Subsystem

UEOSCoreSubsystem is a GameInstanceSubsystem — you access it via Get EOS Core Subsystem or from C++ with GameInstance->GetSubsystem<UEOSCoreSubsystem>().

Initialize EOS

Initialize EOS → bool

Initializes the EOS platform. Must be called once before any other EOS node.

• If OnlineSubsystemEOS is active and has a valid handle → borrows it (no double init).
• Otherwise → reads credentials from DefaultEngine.ini [EOSCore] and creates its own handle.

Shutdown EOS

Shutdown EOS → void

Shuts down EOS cleanly. If the plugin owns the handle, it calls EOS_Platform_Release. If the handle was borrowed from the OSS, it only clears the internal pointer.

You rarely need to call this manually — the subsystem calls it automatically on Deinitialize.

Is Initialized

Is Initialized → bool

Returns true if InitializeEOS has succeeded and the platform handle is still valid.

Is Player Logged In

Is Player Logged In → bool

Returns true if a player has successfully completed both Auth Login and Connect Login.

Get Local Epic Account Id

Get Local Epic Account Id → FString

Returns the Epic Account ID of the logged-in player as a string, or empty if not logged in.

Get Local Product User Id

Get Local Product User Id → FString

Returns the Product User ID (used for all game services) as a string, or empty if Connect Login has not completed.

Get User Info

Get User Info → FEOSCorePlayerInfo

Returns cached player info populated after Auth Login:

Authentication

EOS Auth Login (Epic Account)

EOS Auth Login (Epic Account)
  ├─ WorldContext
  ├─ PrimaryLoginType    [AccountPortal / ExchangeCode / PersistentAuth]
  ├─ Policy              [PersistentThenPortal / PersistentThenExchangeCode / NeverFallback]
  ├─ bDeletePersistentAuthBeforeFallback  [bool]
  ├─► OnSuccess  →  FEOSAuthResult
  └─► OnFailure  →  FEOSAuthResult

Logs the player in with their Epic Games account.

Parameters:

Login Types:

Policies:

Output — FEOSAuthResult:

EOS Connect Login (ProductUserId)

EOS Connect Login (ProductUserId)
  ├─ WorldContext
  ├─► OnSuccess  →  FEOSConnectResult
  └─► OnFailure  →  FEOSConnectResult

Exchanges the Epic Account token for a Product User ID — the player identity used by all game services (Achievements, Stats, Leaderboards).

• If the player is new (first launch), creates their account automatically and fires OnSuccess.
• The Blueprint never needs to handle the "new player" case separately.

Must be called after a successful Auth Login.

Output — FEOSConnectResult:

Why two logins? Auth Login = Epic identity (cross-game). Connect Login = your game identity (per-deployment). This separation allows EOS to support Steam, PlayStation, and Xbox accounts alongside Epic accounts in the future.

Achievements

EOS Query Achievements

EOS Query Achievements
  ├─ WorldContext
  ├─► OnSuccess  →  FEOSAchievementsQueryResult
  └─► OnFailure  →  FEOSAchievementsQueryResult

Fetches all game achievements and the local player's progress in a single node.

Internally runs two EOS requests in sequence:

1. QueryDefinitions — fetches achievement metadata (names, descriptions, icons, hidden status)
2. QueryPlayerAchievements — fetches the player's progress and unlock dates

Both results are merged into a TArray<FEOSAchievementInfo>.

Output — FEOSAchievementsQueryResult:

FEOSAchievementInfo fields:

EOS Unlock Achievement

EOS Unlock Achievement
  ├─ WorldContext
  ├─ Achievement        [FEOSAchievementInfo]
  ├─ IngestAmount       [int32, default: 1]
  ├─► OnSuccess  →  FEOSUnlockResult
  └─► OnFailure  →  FEOSUnlockResult

Unlocks the achievement for the local player.

The unlock method is chosen automatically from the FEOSAchievementInfo you pass:

Parameters:

Output — FEOSUnlockResult:

Notes:

• If the achievement is already unlocked, EOS still returns EOS_Success. You do not need to check before calling.
• If the AchievementId does not exist in the Dev Portal, EOS returns EOS_NotFound.
• After a successful unlock, the node automatically refreshes the local EOS cache (QueryPlayerAchievements) so subsequent queries reflect the new state.

EOS Start Achievements Unlocked Listener

EOS Start Achievements Unlocked Listener
  ├─ WorldContext
  ├─► OnStarted   →  FEOSAchievementInfo, bool bSuccess
  └─► OnUnlocked  →  FEOSAchievementInfo, bool bSuccess

Registers a persistent real-time listener that fires OnUnlocked every time an achievement is unlocked for the local player — including unlocks triggered by stat thresholds on the server side.

• OnStarted fires once when the listener is successfully registered.
• OnUnlocked fires each time an achievement is unlocked, with the full FEOSAchievementInfo populated.

Stopping the listener:

Call EOS Stop Achievements Unlocked Listener on the node reference to unregister and clean up.

EOS Stop Achievements Unlocked Listener
  ├─ Target  [reference to the listener node]

The listener is also automatically stopped if the node is garbage collected.

Utility Functions (EOSHelpers)

These are C++-only inline helpers available in the EOSHelpers namespace. They are used internally but can also be used in C++ code.

Error Codes

Common EOS error codes you may see in ErrorMessage fields:

For a full list, see the EOS SDK Result Codes reference.