prototype

A throwaway game prototype used to test whether a core idea is worth developing. It chooses a web, game-engine, or paper-based approach and ends with a proceed, pivot, or kill decision.

In plain words
What is it for?
For quickly testing game concepts and deciding whether to continue, change direction, or stop.
Why use it?
It helps validate the central gameplay idea before the team spends time writing detailed design documents.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/frabcd/codex-ai-game-studio/prototype
Any agent
npx skills add frabcd/codex-ai-game-studio --skill prototype
Clone the repo
git clone --depth 1 https://github.com/frabcd/codex-ai-game-studio

Made for: Claude Code, Codex.

Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 308 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00071 $0.00308
Opus 5 $0.00036 $0.00154
Sonnet 5 $0.00014 $0.00062
Haiku 4.5 $0.00007 $0.00031

Measured 2d ago against content hash e75559444af4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prototype 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 2d 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/ai-game-studio/skills/prototype/SKILL.md · 26 lines

What it actually says

Port provenance: adapted from the pinned upstream source at 984023ddac0d5e27624f2baacde6105e45de375f under MIT; see the repository parity ledger for the exact path and blob.

Prototype

This is a full-fidelity Codex port of a large upstream studio workflow. Its detailed phases, templates, checks, and handoff prompts live in references/full-workflow.md to keep skill discovery lightweight.

Required procedure

  1. Read references/full-workflow.md completely before executing this skill.
  2. Follow its phases in order and preserve all approval, review, testing, and evidence gates.
  3. Adapt shell syntax to the detected platform; use PowerShell on Windows and POSIX syntax on macOS/Linux.
  4. Inherit the active Codex model and permission mode. Never weaken sandbox, approval, provenance, or human creative-control boundaries.
  5. If a referenced project artifact is absent, report the gap and use the documented fallback instead of inventing completion evidence.
Files

What ships with it

2 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.

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. 2d ago First seen · 26 lines · 71 tokens per session scan A e75559444af4

Subscribe to this mod's changes

prototype is a skill published in the GitHub repository frabcd/codex-ai-game-studio (7 stars, last pushed 9d ago), licensed MIT. It adds 71 tokens to every session and 308 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 2026-08-31.

Related

Other skills, from other repositories

3d_object

Judge whether a generated mesh is fit to ship in a browser game, from the same rendered sheet the orientation review uses.

OpenDCAI/GameFactory-3A · 0 tokens

motion

How an agent turns a character mesh into a usable animated FBX — and how to judge whether the result is shippable.

OpenDCAI/GameFactory-3A · 0 tokens

cg_video

Use this Skill for text-to-video, first-frame-to-video, first/last-frame transitions, and reference-image-conditioned CG-video generation. Generate video only after the game plan defines its narrative purpose, visual style, shot, duration, and acceptance criteria.

OpenDCAI/GameFactory-3A · 0 tokens

image

Use this Skill when a game plan needs a single-subject concept image, a character reference cleaned for image-to-3D, or a front-facing transparent T-pose image for downstream character reconstruction. T-pose generation is an image-generation and image-editing task; it is not a separate asset category.

OpenDCAI/GameFactory-3A · 0 tokens

audio

Use this Skill when a game plan requires dialogue, voice lines, sound effects, foley, ambience, or other offline WAV assets. This is asset generation, not a runtime audio-playback contract; use the selected engine context after an asset has passed review.

OpenDCAI/GameFactory-3A · 0 tokens

game-cg-director

Convert game CG intent and optional media references into validated, model-specific directing envelopes for opening, cutscene, ultimate, or promo clips. Use for standalone CG prompt direction or as a child capability of a game-generation Harness. Supports T2VA/text-only, I2VA/first-frame image…

OpenDCAI/GameFactory-3A · 95 tokens