Unreal Engine API reference
that actually makes sense.
Community-maintained documentation for UE 5.6 C++ and Blueprint APIs. Real signatures, real caveats, real examples.
Browse by Category
Core
Base object model, reflection system, garbage collection.
Engine
Actors, components, world management, gameplay framework.
Math & Containers
FVector, FRotator, FTransform, TArray, TMap, TSet.
AI
Behavior Trees, AI Controllers, Perception system.
Networking
Replication, RPCs, Online Subsystem.
Rendering
Materials, render targets, post-processing, shaders.
Guides
Unreal's Core Classes
UObject, Actors, Components, Pawns, Controllers, and Widgets — what each is for, how they relate, and which one to derive from.
The Gameplay Framework
GameMode, GameState, PlayerController, PlayerState, GameInstance — who creates what, what replicates where, and why the design is multiplayer-first.
Event Execution Order
Actor lifecycle, tick groups, BeginPlay ordering, replication timing, and common gotchas.
UMG/Slate Coordinate Spaces
Desktop/Absolute, game-screen pixels, scaled Viewport, and widget Local space — how they relate, plus a cookbook for every common conversion.