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 ouzlifaneyassine1-dot/onyx-engine --skill gameskillgit clone --depth 1 https://github.com/ouzlifaneyassine1-dot/onyx-engineWrote 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/ouzlifaneyassine1-dot/onyx-engine/gameskill)<a href="https://agentmods.dev/skills/ouzlifaneyassine1-dot/onyx-engine/gameskill"><img src="https://agentmods.dev/badge/skills/ouzlifaneyassine1-dot/onyx-engine/gameskill/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/ouzlifaneyassine1-dot/onyx-engine/gameskill"><img src="https://agentmods.dev/badge/skills/ouzlifaneyassine1-dot/onyx-engine/gameskill.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 | $0.00058 | $0.02218 |
| Opus 5 | $0.00029 | $0.01109 |
| Sonnet 5 | $0.00012 | $0.00444 |
| Haiku 4.5 | $0.00006 | $0.00222 |
Grade A, and why
gameskill 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 6d 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 — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/gameskill — Capture Session Learnings into the Skill Library
You're being invoked at the end (or middle) of a game-development session. Your job is to turn what you just figured out into a durable skill update so future agents and onyx users get to start where you ended.
This is the meta-skill: the loop that turns ad-hoc fixes into reusable expertise.
What "Onyx Engine" is, so you're grounded
Three repos, one ecosystem:
- OnyxEngine repo — the desktop engine (Godot fork in C++) plus the canonical CLI. Engine source:
editor/,core/, and the Summer-specific module atmodules/1onyx_engine/. CLI source:tools/onyx-cli/. The CLI ships asnpm i -g onyx-engine. It does install/login/create/run for the engine, plusonyx skills install --agent claude-codewhich writes a curated subset of skills into~/.claude/skills/for any agent to auto-discover. - PublicOnyxEngine repo — the web app at OnyxEngine.com. Has its own AI skill stores at
src/lib/ai/skills/bundled/andpublic/knowledge/onyx/skills/for the in-browser chat agent. Also has its own consumers of the engine API insrc/lib/bridge/direct-executor.tsandsrc/lib/ai/tools/run-and-verify.tswhich call the same engine endpoints the CLI does. - The active game project — usually
~/development/<game-name>(Godot 4.6) or whatever game you were just working on. Real working code in this repo is the gold standard for examples.
The skill system is the value flywheel. Every game shipped teaches lessons. Lessons become skills. Next user starts smarter. Your job here is to close that loop for what you just did.
Cross-repo change awareness — read before any non-trivial fix
When the lesson is "the engine should expose more / behave differently," the change usually crosses repo boundaries. Map the layers before you edit:
[active game] -> calls MCP / web app
v
[onyx-cli MCP server (TypeScript)] -> calls /api/ops + /api/state/* on the engine
v
[Onyx Engine binary (C++ in OnyxEngine repo)] - source of truth for what the API returns
[PublicOnyxEngine web app (TypeScript)] -> also calls the same engine endpoints via direct-executor or Redis bridge
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.
- 6d ago First seen · 112 lines · 58 tokens per session scan A 2b7bc9362502
gameskill is a skill published in the GitHub repository ouzlifaneyassine1-dot/onyx-engine (0 stars, last pushed 2mo ago), licensed MIT. It adds 58 tokens to every session and 2,218 once invoked, about $0.0003 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.
Other skills, from other repositories
gameskill
Use when finishing a game-development session and you want to capture what you just learned into Summer's canonical skill library so the next session and every Summer user start smarter. Trigger on "gameskill", "/gameskill", "capture learnings", "save to skills".
game-engine
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ai-llm-runtime-integration
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architecture-review
Validates architecture against all GDDs: traceability matrix, coverage gaps, cross-ADR conflicts, engine compatibility, PASS/CONCERNS/FAIL verdict.
brainstorm
Guided game concept ideation — from zero idea to a structured game concept document. Uses professional studio ideation techniques, player psychology frameworks, and structured creative exploration.
analytics-privacy-anonymization
Anonymize analytics data to protect player privacy.