Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add kevinpbuckley/VibeUE --skill behavior-treesgit clone --depth 1 https://github.com/kevinpbuckley/VibeUEWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/kevinpbuckley/vibeue/behavior-trees)<a href="https://agentmods.dev/skills/kevinpbuckley/vibeue/behavior-trees"><img src="https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/behavior-trees/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kevinpbuckley/vibeue/behavior-trees"><img src="https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/behavior-trees.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00086 | $0.01972 |
| Opus 5 | $0.00043 | $0.00986 |
| Sonnet 5 | $0.00017 | $0.00394 |
| Haiku 4.5 | $0.00009 | $0.00197 |
Grade A, and why
behavior-trees scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.
🧠 Brains complement: IF an
unreal-engine-skills-managertool (external MCP) exists in this session, call it with{action: "load", skill: "ai-and-navigation"}for UE domain knowledge on Behavior Trees — architecture, node semantics, best practices. If no such tool is available, skip this line entirely and proceed with this skill alone — do NOT attempt the call.
Behavior Trees Skill
Two services, reachable from Python (unreal.BehaviorTreeService.*, unreal.BlackboardService.*)
and as AICallable tools:
BlackboardService → UBlackboardData assets: create, key CRUD, metadata, re-parenting
BehaviorTreeService → UBehaviorTree assets: structure, sub-nodes, properties, build, validate
Discover exact signatures with discover_python_class('unreal.BehaviorTreeService') — this skill
teaches the concepts and the gotchas, not the call shapes.
The golden workflow
import unreal
BT = unreal.BehaviorTreeService
BB = unreal.BlackboardService
# 1. Blackboard first — key bindings resolve against the TREE'S board, so assign it at creation.
BB.create_blackboard("/Game/AI/BB_Guard")
BB.add_blackboard_key("/Game/AI/BB_Guard", "TargetActor", "Object")
BB.set_blackboard_key_object_class("/Game/AI/BB_Guard", "TargetActor", "/Script/Engine.Actor")
# 2. Tree on that board.
BT.create_behavior_tree("/Game/AI/BT_Guard", "/Game/AI/BB_Guard")
# 3. Structure. Every mutator returns the new node's PATH (or "ERROR: ...").
sel = BT.add_node("/Game/AI/BT_Guard", "Root", "BTComposite_Selector") # Root/Selector[0]
seq = BT.add_node("/Game/AI/BT_Guard", sel, "BTComposite_Sequence")
wait = BT.add_node("/Game/AI/BT_Guard", seq, "BTTask_Wait")
# 4. Properties and bindings.
BT.set_node_property_value("/Game/AI/BT_Guard", wait, "WaitTime", '(DefaultValue=3.5,Key="")')
dec = BT.add_decorator("/Game/AI/BT_Guard", seq, "BTDecorator_Blackboard")
BT.set_node_blackboard_key("/Game/AI/BT_Guard", dec, "BlackboardKey", "TargetActor")
# 5. Verify.
print(BT.validate_tree("/Game/AI/BT_Guard")) # [] == clean
print(BT.get_tree("/Game/AI/BT_Guard")) # whole tree as JSON
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 149 lines · 86 tokens per session scan A f3708c3491c8
behavior-trees is a skill published in the GitHub repository kevinpbuckley/VibeUE (659 stars, last pushed 5d ago), licensed MIT. It adds 86 tokens to every session and 1,972 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
ai-behavior-engineer
You are the AI Behavior Engineer Specialist. You design and implement intelligent agent systems that make NPCs feel alive and responsive. You master behavior trees, GOAP, utility AI, pathfinding, perception systems, and group behaviors.
structural-pattern-selector
Choose the right structural design pattern (Adapter, Bridge, Composite, Decorator, Facade, Flyweight, or Proxy) for a structural design problem. Use when you need to adapt interfaces between incompatible classes, decouple an abstraction from its implementation so both can vary independently, build part-whole…
gameobject-component-destroy
Destroy one or more Components from a target GameObject. Missing (null) components are skipped — they cannot be destroyed. Use 'gameobject-find' and 'gameobject-component-get' to identify the components first.
unity-version-split
Split a C# file into Unity 6.5+ and pre-Unity 6.5 variants. Use when a file needs different implementations for different Unity versions due to API changes (e.g., EntityId vs int, GetEntityId vs GetInstanceID).
unity-addressables
Manage Addressables groups, entries, profiles and content builds (com.unity.addressables, reflection-based).
motion
How an agent turns a character mesh into a usable animated FBX — and how to judge whether the result is shippable.