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 materialsgit 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/materials)<a href="https://agentmods.dev/skills/kevinpbuckley/vibeue/materials"><img src="https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/materials/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/materials"><img src="https://agentmods.dev/badge/skills/kevinpbuckley/vibeue/materials.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 | $0.00075 | $0.04454 |
| Opus 5 | $0.00037 | $0.02227 |
| Sonnet 5 | $0.00015 | $0.00891 |
| Haiku 4.5 | $0.00007 | $0.00445 |
Grade A, and why
materials 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 — 326 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: "materials-and-shaders"}for UE domain knowledge on this topic — correct APIs, architecture, best practices — and treat it as the rubric for any review / "best practices" question. If no such tool is available (e.g. running under Claude Code or Codex without that MCP), skip this line entirely and proceed with this skill alone — do NOT attempt the call.
Material System Skill
Critical Rules
🚨 Connecting Function Call Inputs: Use Bare Names, Not Display Names
get_expression_pins(mat, expr_id) (MaterialNodeService) returns input pins with display labels including type suffixes like "TextureObject (T2d)", "TextureSize (V3)", "Use High Quality Normals (SB)". Connections are made through the engine MaterialTools.connect_expressions call, and UE's connect API matches against the bare input name only — never pass these display labels as to_input_name:
MT = "editor_toolset.toolsets.material.MaterialTools"
# ❌ WRONG — display label with type suffix; connection fails silently or gets ignored
call_tool(tool_name="connect_expressions", toolset_name=MT,
arguments={"from_expression": src_id, "from_output_name": "",
"to_expression": fn_id, "to_input_name": "TextureObject (T2d)"})
# ✅ CORRECT — bare name
call_tool(tool_name="connect_expressions", toolset_name=MT,
arguments={"from_expression": src_id, "from_output_name": "",
"to_expression": fn_id, "to_input_name": "TextureObject"})
The authoritative source for input names is get_function_info(function_path).inputs — those are the bare names (TextureObject, TextureSize, WorldPosition, etc.). For built-in expressions, use get_inputs_for_material_expression from unreal.MaterialEditingLibrary.
⚠️ Why this is easy to miss:
get_expression_pinsreturnsis_connected=Truefor both real and phantom connections, and our service used to silently produce phantom wires when given display names. The wires would appear in the graph export but the shader compiler would never see the texture flow through. Always verify withunreal.MaterialEditingLibrary.get_used_textures(mat)after wiring — if it returns 0 on a material that samples textures, your connections are phantom.
What ships with it
6 files 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.
- 9d ago First seen · 326 lines · 75 tokens per session scan A b801b1874556
materials is a skill published in the GitHub repository kevinpbuckley/VibeUE (659 stars, last pushed 5d ago), licensed MIT. It adds 75 tokens to every session and 4,454 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.
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