asset-spec

asset-spec is a skill for Claude Code from bullish0x/GameStudio. It costs 54 tokens per session (3,896 once invoked), scanned A, a copy of asset-spec, MIT.

A game-art planning tool that turns design documents into per-asset visual specifications and image-generation prompts.

In plain words
What is it for?
Use it after the art rules and game design are approved to create asset specs and update the project's asset inventory.
Why use it?
It gives the art team a shared description of what each required character, screen, item, or other visual should contain before production starts.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: names the AskUserQuestion tool; installed under .agents/ (shared by several agents).

Good fit Use it after the art rules and game design are approved to create asset specs and update the project's asset inventory.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bullish0x/gamestudio/asset-spec
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 bullish0x/GameStudio --skill asset-spec
Clone the repo
git clone --depth 1 https://github.com/bullish0x/GameStudio

Made for: Claude Code.

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 asset-spec

README.md
[![agentmods](https://agentmods.dev/badge/skills/bullish0x/gamestudio/asset-spec/github.svg)](https://agentmods.dev/skills/bullish0x/gamestudio/asset-spec)
Your own site
<a href="https://agentmods.dev/skills/bullish0x/gamestudio/asset-spec"><img src="https://agentmods.dev/badge/skills/bullish0x/gamestudio/asset-spec/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 asset-spec

Your own site · 80×15
<a href="https://agentmods.dev/skills/bullish0x/gamestudio/asset-spec"><img src="https://agentmods.dev/badge/skills/bullish0x/gamestudio/asset-spec.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,896 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.
Origin 100% copy Near-identical to another mod 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 $0.00054 $0.03896
Opus 5 $0.00027 $0.01948
Sonnet 5 $0.00011 $0.00779
Haiku 4.5 $0.00005 $0.00390

Measured 7d ago against content hash 766b3fa54aea, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

asset-spec 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 7d 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.

Origin

This is a copy

100% identical to asset-spec — 3 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/asset-spec/SKILL.md · 352 lines

How it starts

The opening of the file, as written. The whole thing — 352 lines — stays where its author put it; the contents beside it link to each section on GitHub.

If no argument is provided, check whether design/assets/entity-inventory.md exists:

  • If it exists: read it, find the first entity or screen with status "Needed" but no spec file yet, and use AskUserQuestion:
    • Prompt: "The next unspecced item is [name]. Generate specs for it?"
    • Options: [A] Yes — spec [name] / [B] Pick a different item / [C] Stop here
  • If no entity inventory: check design/assets/asset-manifest.md. If manifest exists, same flow above but reading from manifest.
  • If neither exists: start the Entity & Screen Inventory flow (Phase 0b below) rather than failing.

Phase 0b: Entity & Screen Inventory (runs when no arguments and no existing inventory)

This flow produces design/assets/entity-inventory.md — the master list of everything the game needs visually. Run once before asset spec work begins.

Step 1 — Gather from docs

Read all available source material in parallel:

  • design/gdd/systems-index.md — extract every system listed
  • All GDDs in design/gdd/ — extract: Visual/Audio Requirements sections, UI elements mentioned, VFX events, any named entities (characters, enemies, buildings, items)
  • design/art/art-bible.md — extract: any named visual categories, asset type expectations
  • design/narrative/ — scan for any character or world entity documents if they exist (optional — not required)

Step 2 — Build proposed inventory

Organize everything found into categories:

Characters / Protagonists
Enemies / Creatures
Buildings / Structures
Environment / Terrain
Items / Props
VFX / Particles
UI Screens (list each screen by name)
HUD Elements
Audio (SFX, music — descriptions only, no generation prompts)
Other

For each item, note the source doc it was found in.

Step 3 — Present and collaborate

Present the full proposed inventory to the user in conversation. Then use AskUserQuestion:

  • Prompt: "I found [N] visual entities and [N] UI screens across your GDDs and art bible. Review the list — what's missing, what's not needed?"
  • Options:
    • [A] Looks good — save this inventory
    • [B] Add items I'll describe
    • [C] Remove items that don't apply
    • [D] Both add and remove — let me edit

Read the full file on GitHub · 352 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. 7d ago First seen · 352 lines · 54 tokens per session scan A 766b3fa54aea

Subscribe to this mod's changes

asset-spec is a skill published in the GitHub repository bullish0x/GameStudio (12 stars, last pushed 2mo ago), licensed MIT. It adds 54 tokens to every session and 3,896 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to asset-spec, differing in 3 lines, and is treated as a copy.

Related

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