// the find
Tencent/behaviac
behaviac is a framework of the game AI development, and it also can be used as a rapid game prototype design tool. behaviac supports the behavior tree, finite state machine and hierarchical task network(BT, FSM, HTN)
Behaviac is Tencent's in-house game AI framework that lets designers author behavior trees, FSMs, and HTN planners in a visual editor, then export them as XML files the C++ or C# runtime executes. It was used in production at Tencent and the codebase reflects that — it's not a toy. Target audience is game studios that want designer-friendly AI authoring without writing the runtime from scratch.
The three-paradigm support (BT, FSM, HTN) in one editor is genuinely useful — you can mix them, with FSM states that trigger BTs, which most alternatives don't do out of the box. The C++ runtime has its own allocators, object pools, and a custom container layer, so it won't fight your engine's memory management. Real-time debugging over a socket connection — the editor can attach to a running game and visualize the active tree live — is the kind of feature most open-source BT libraries skip entirely. The C# port mirrors the C++ API closely enough that cross-team code sharing is realistic.
Last commit was July 2023 and the official website (behaviac.com) is the actual documentation hub — if that goes down, you're reading Chinese-only comments in source files. The XML export format is the integration contract between editor and runtime, and it's underdocumented; if you need to modify the editor (Windows-only, closed binary in the setup package), you're largely on your own. Unity integration exists but isn't a proper package — it's a code drop you embed manually, which means upgrades are painful. The HTN planner is real but thin; anyone expecting SHOP2-style expressiveness will hit walls fast.