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 gamedev-skills/awesome-gamedev-agent-skills --skill prototype-fastgit clone --depth 1 https://github.com/gamedev-skills/awesome-gamedev-agent-skillsWrote 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/gamedev-skills/awesome-gamedev-agent-skills/prototype-fast)<a href="https://agentmods.dev/skills/gamedev-skills/awesome-gamedev-agent-skills/prototype-fast"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/prototype-fast/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/gamedev-skills/awesome-gamedev-agent-skills/prototype-fast"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/prototype-fast.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- 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 | $0.00064 | $0.01441 |
| Opus 5 | $0.00032 | $0.00720 |
| Sonnet 5 | $0.00013 | $0.00288 |
| Haiku 4.5 | $0.00006 | $0.00144 |
Grade A, and why
prototype-fast 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 — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prototype Fast
Get a mechanic into a player's hands fast to learn whether it's worth building. The output of a prototype is a decision (keep / kill / refactor), not a product. Optimize for learning speed, and decide up front whether the code is throwaway or load-bearing.
When to use
- Use when validating a single mechanic or "what if", building a vertical slice / MVP, greyboxing a level or interaction, or de-risking an idea before committing real time.
- Use when the user says "just get something playable", "is this fun?", or "rough it in".
When not to use: a timed competition with a deadline and a submission (use game-jam);
shipping or updating a real release (use steam-publish / itch-publish); building the
production version of a validated feature (use the engine/genre skill directly).
Core workflow
- Write the one question. State the single thing the prototype must answer, e.g. "Is grappling-while-falling satisfying to control?" If you have two questions, build two prototypes. A prototype that tests everything tests nothing.
- Decide throwaway vs keep — before you write code. Throwaway (a spike): hard-code, no architecture, delete after. Keep: still rough, but folder/names you can grow. Most prototypes should be throwaway; pretending otherwise is how prototypes rot into the shipping codebase.
- Set a hard timebox (30-90 min for a mechanic; one sitting for a slice) and a visible timer. The constraint is the point — it forces you to test the core idea, not the trim.
- Greybox everything non-essential. Primitives for art (boxes, circles, capsules), built-in fonts, one debug sound or none. Spend zero minutes on anything the question doesn't depend on.
- Instrument for the question. Add on-screen debug text / gizmos that show the thing you are judging (speed, distance, timing window). You're measuring, not decorating.
- Playtest immediately and honestly. Play it yourself, then hand it to one other person without explaining the controls. Watch where they struggle.
- Make the call against your kill criteria (below). Keep → schedule the real build and rewrite, don't promote the spike. Kill → log the lesson and move on. Refactor → narrow the question and spike again.
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 · 120 lines · 64 tokens per session scan A 02491395c621
prototype-fast is a skill published in the GitHub repository gamedev-skills/awesome-gamedev-agent-skills (952 stars, last pushed 2d ago), licensed Apache-2.0. It adds 64 tokens to every session and 1,441 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
assets-get-data
Get asset data from the asset file in the Unity project — every serializable field and property. Supports token-saving path-scoped reads via paths or viewQuery. Use 'assets-find' to find the asset first.
gameobject-set-parent
Reparent a batch of GameObjects under a new parent in the currently opened Prefab or active Scene. Per-item failures are reported in the returned status string instead of aborting the batch. Use 'gameobject-find' to locate the GameObjects 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).
profiler-save-data
Save a snapshot of profiler-derived stats (status + memory + rendering + script + frame capture) to a JSON file. Built-in Unity APIs only.
assets-shader-list-all
List all shaders available in the project assets and packages, sorted by name. Use this to discover a valid shaderName for 'assets-material-create'.
profiler-stop
Disable Unity's runtime profiler. Idempotent — calling when already disabled returns the current disabled state.