unreal-engine

unreal-engine is a skill for Claude Code, Codex from metaspartan/cybara. It costs 49 tokens per session (706 once invoked), scanned A, original, MIT.

A set of practices for building Unreal Engine projects with C++, Blueprints, tests, and Unreal's build and packaging tools. Unreal Engine is a tool for making games and other real-time 3D applications.

In plain words
What is it for?
It supports implementing, debugging, testing, packaging, and optimizing Unreal Engine projects.
Why use it?
It helps locate the right project files and diagnose engine-specific problems without damaging serialized assets or breaking engine conventions.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It supports implementing, debugging, testing, packaging, and optimizing Unreal Engine projects.

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Install with agentmods
npx agentmods add skills/metaspartan/cybara/unreal-engine
Install

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.

Any agent
npx skills add metaspartan/cybara --skill unreal-engine
Clone the repo
git clone --depth 1 https://github.com/metaspartan/cybara

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for unreal-engine

README.md
[![agentmods](https://agentmods.dev/badge/skills/metaspartan/cybara/unreal-engine/github.svg)](https://agentmods.dev/skills/metaspartan/cybara/unreal-engine)
Your own site
<a href="https://agentmods.dev/skills/metaspartan/cybara/unreal-engine"><img src="https://agentmods.dev/badge/skills/metaspartan/cybara/unreal-engine/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.

agentmods 80×15 button for unreal-engine

Your own site · 80×15
<a href="https://agentmods.dev/skills/metaspartan/cybara/unreal-engine"><img src="https://agentmods.dev/badge/skills/metaspartan/cybara/unreal-engine.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 706 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.00706
Opus 5 $0.00024 $0.00353
Sonnet 5 $0.00010 $0.00141
Haiku 4.5 $0.00005 $0.00071

Measured 3d ago against content hash d775fc14d1e2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

unreal-engine 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 3d 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.

plugins/game-development/skills/unreal-engine/SKILL.md · 51 lines

How it starts

The opening of the file, as written. The whole thing — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unreal Engine

Inspect first

  1. Locate the .uproject file and read its engine association and enabled plugins.
  2. Inspect Source, project plugins, Config, target files, module build files, and nearby tests.
  3. Determine whether the behavior belongs in C++, Blueprint, data assets, editor tooling, or configuration.
  4. Discover the installed editor and RunUAT or RunUBT entrypoint without assuming one platform path.

Never text-edit .uasset or .umap files. Use source changes, configuration, commandlets, or an engine-aware editor workflow.

Implementation rules

  • Keep gameplay rules out of actors and widgets when a subsystem, component, or plain testable type is a better owner.
  • Preserve reflection macros, module boundaries, object lifetime, replication authority, and thread affinity.
  • Treat asset references and gameplay tags as contracts; verify renames and redirects.
  • Avoid broad Blueprint reconstruction or resaves for a focused code change.
  • Do not rely on hot reload as final verification after changing reflected types.

Verification

Use the project's existing scripts when present. Otherwise select the narrowest engine-native checks:

  1. Compile the affected target with Unreal Build Tool.
  2. Run relevant Automation Tests through the editor or command line.
  3. Use a command shaped like UnrealEditor-Cmd <project> -ExecCmds="Automation RunTest <filter>;Quit" -ReportExportPath=<path> -unattended -nop4 only after resolving the actual executable and test filter.
  4. Use Automation Tool for build, cook, stage, package, deploy, or Gauntlet flows already supported by the project.
  5. Launch the correct map and exercise the changed player flow.
  6. Inspect logs for ensures, access violations, asset load failures, shader failures, and automation errors.

Headless automation and visual verification

  1. Drive editor automation with Python when no C++ change is needed: UnrealEditor-Cmd <project.uproject> -run=pythonscript -script=<absolute script.py> -unattended -nop4 -nosplash after resolving the real editor binary; enable the Python Editor Script Plugin first.
  2. Keep each generated script small and split large scripts across several write or edit calls; a tool call cut off by the output limit loses its arguments.
  3. For visual checks, capture stills with HighResShot console commands, unreal.AutomationLibrary.take_high_res_screenshot, or a Movie Render Queue job, writing PNG files to absolute paths.
  4. Inspect every capture with the image tool, compare it with the requested result, fix, re-run, and inspect again before reporting.
  5. Keep captures you reported to the user; write new versions to new file names.

Read the full file on GitHub · 51 lines

Changes

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.

  1. 3d ago Changed · +8 lines d775fc14d1e2
  2. 7d ago First seen · 43 lines · 49 tokens per session scan A effbe9ec5c8d

Subscribe to this mod's changes

unreal-engine is a skill published in the GitHub repository metaspartan/cybara (28 stars, last pushed yesterday), licensed MIT. It adds 49 tokens to every session and 706 once invoked, about $0.0002 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 2026-09-03.

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