Borrowing it
Nothing to install: this file belongs to ukanwat/aaabench. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/ukanwat/aaabench/main/.claude/skills/unreal-behavior-trees/SKILL.mdgit clone --depth 1 https://github.com/ukanwat/aaabenchWrote 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/ukanwat/aaabench/unreal-behavior-trees)<a href="https://agentmods.dev/skills/ukanwat/aaabench/unreal-behavior-trees"><img src="https://agentmods.dev/badge/skills/ukanwat/aaabench/unreal-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/ukanwat/aaabench/unreal-behavior-trees"><img src="https://agentmods.dev/badge/skills/ukanwat/aaabench/unreal-behavior-trees.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00087 | $0.01479 |
| Opus 5 | $0.00044 | $0.00740 |
| Sonnet 5 | $0.00017 | $0.00296 |
| Haiku 4.5 | $0.00009 | $0.00148 |
Grade A, and why
unreal-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 10d 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.
This is a copy
91% identical to unreal-behavior-trees — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Unreal Behavior Trees
Author NPC decision-making in UE5 with Behavior Trees driven by a Blackboard: structure the tree with composites, gate branches with decorators, keep state current with services, and run it from an AIController. Targets UE 5.4+.
When to use
- Use when building enemy/NPC AI: creating a
BT_/BB_asset pair, structuring Selector/Sequence branches, adding decorators (conditions) and services (periodic updates), writing customBTTask/BTServicenodes, or wiring an AIController to run the tree. - Use when the project has Behavior Tree (
BT_) and Blackboard (BB_) assets and anAAIController.
When not to use: the concept of AI (FSM vs BT vs steering, cross-engine) →
game-ai. Pure navigation/pathing math is engine navmesh (BT's MoveTo uses it). Simple
one-off logic may be cheaper as a small state machine than a full tree.
Core workflow
- Create the pair: a Blackboard (
BB_) holds typed keys (the AI's memory:TargetActor,LastKnownLocation,bIsInvestigating); a Behavior Tree (BT_) references that Blackboard. - Possess and run. An
AAIControllerpossesses the pawn and callsRunBehaviorTree(BT), which also initializes the referenced Blackboard. - Structure with composites. Selector runs children left→right until one succeeds (priority/fallback: "attack, else chase, else patrol"). Sequence runs children until one fails (do-all: "move to cover → reload → peek"). Simple Parallel runs one main task alongside a secondary.
- Gate branches with Decorators that read Blackboard keys (e.g. "Has Target?" guards the combat branch). Set Observer Aborts so the tree re-evaluates when the key changes.
- Keep the Blackboard current with Services attached to a branch — they tick periodically
(e.g. update
TargetActorvia a sight check) only while that branch is active. - Do work in Tasks, which return
Succeeded,Failed, orInProgress(latent tasks likeMoveTofinish later). - Verify with the Behavior Tree debugger during PIE — it highlights the running node and shows live Blackboard values, so you see exactly which branch executes.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 121 lines · 87 tokens per session scan A 45478a626c3b
unreal-behavior-trees is a skill published in the GitHub repository ukanwat/aaabench (382 stars, last pushed 25d ago), licensed MIT. It adds 87 tokens to every session and 1,479 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to unreal-behavior-trees, differing in 8 lines, and is treated as a copy.
Other skills, from other repositories
unreal-engineer
!cat skills/shared/protocols/3d-spatial-foundations.md 2>/dev/null || echo "=== 3D Foundations not loaded ===".
unreal-playtest-agent
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unreal-pie
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unreal-actors
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unreal-blueprints
Domain skill - Unreal Engine Blueprint editing: create Blueprint classes, add event/function nodes, connect nodes, add variables, and compile. Use when building or modifying Blueprint logic in the Unreal Editor. Not for level actor placement - use unreal-actors for that.
unreal-cinematics
Domain skill — Sequencer shot and keyframe orchestration, camera cut tracks, and Movie Render Queue job setup. Use when creating or editing Level Sequences, authoring camera animation, or preparing an MRQ job in Unreal Engine 5. Not for Blueprint scripting (unreal-blueprints) or runtime playback (unreal-runtime).