Behavior trees plus hierarchical state machines for Godot 4, shipped as a GDExtension with a dedicated editor panel and its own debugger. The combination is the point: a state machine handles coarse modes such as patrol, combat, and flee, while a behavior tree handles the decision detail inside each mode. Heavier to install than a pure GDScript addon, and faster at runtime because the core is compiled.
At a glance
Licence
MIT
Commercial use
commercial OK
Credit
Not required
Status
active: License spot-checked at the source; the entry carries dated evidence.
Distributed as a GDExtension binary per platform, or as a custom Godot build; the binary set must cover every export target you ship, including web if you need it
Blackboard variables are typed and scoped per tree, which avoids the shared-global-dictionary pattern that makes hand-rolled trees fragile
Tasks can be written in GDScript or C++; GDScript tasks are the normal path and hot-reload during play
Ships a behavior tree debugger panel that shows live task status, worth the install cost on its own for a project with many enemy types
The LICENSE.md file carries verbatim MIT terms without an "MIT License" title line; the terms themselves are unambiguous
Evidence
LICENSE.md in the repository, master branch (2026-08-24): "Copyright (c) 2023-2025 Serhii Snitsaruk and the LimboAI contributors."
Same file (2026-08-24): "to deal in the Software without restriction"