propagate-design-change

propagate-design-change is a skill for Codex from frabcd/codex-ai-game-studio. It costs 44 tokens per session (2,020 once invoked), scanned A, original, MIT.

A change-impact review for a game design document, or GDD—the document describing how a game should work. It checks architectural decision records, which explain why technical choices were made, against a revised GDD.

In plain words
What is it for?
Use it after revising a GDD to find affected architecture decisions, compare old assumptions with the new design, and produce an impact report.
Why use it?
When game design changes, older technical decisions may no longer fit. This review identifies those decisions and guides their resolution.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions subagents; mentions Codex; $skill-name invocation.

Good fit Use it after revising a GDD to find affected architecture decisions, compare old assumptions with the new design, and produce an impact report.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/frabcd/codex-ai-game-studio/propagate-design-change
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 frabcd/codex-ai-game-studio --skill propagate-design-change
Clone the repo
git clone --depth 1 https://github.com/frabcd/codex-ai-game-studio

Made for: 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 propagate-design-change

README.md
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Your own site
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Your own site · 80×15
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Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,020 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 $0.00044 $0.02020
Opus 5 $0.00022 $0.01010
Sonnet 5 $0.00009 $0.00404
Haiku 4.5 $0.00004 $0.00202

Measured 9d ago against content hash 93e1f303c853, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

propagate-design-change 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.

plugins/ai-game-studio/skills/propagate-design-change/SKILL.md · 241 lines

How it starts

The opening of the file, as written. The whole thing — 241 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Propagate Design Change

When a GDD changes, architectural decisions written against it may no longer be valid. This skill finds every affected ADR, compares what the ADR assumed against what the GDD now says, and guides the user through resolution.

Usage: $ai-game-studio:propagate-design-change design/gdd/combat-system.md


1. Validate Argument

A GDD path argument is required. If missing, fail with:

"Usage: $ai-game-studio:propagate-design-change design/gdd/[system].md Provide the path to the GDD that was changed."

Verify the file exists. If not, fail with:

"[path] not found. Check the path and try again."


2. Read the Changed GDD

Read the current GDD in full.


3. Read the Previous Version

Run git to get the previous committed version:

git show HEAD:design/gdd/[filename].md

If the file has no git history (new file), report:

"No previous version in git — this appears to be a new GDD, not a revision. Nothing to propagate."

If git returns the previous version, do a conceptual diff:

  • Identify sections that changed (new rules, removed rules, modified formulas, changed acceptance criteria, changed tuning knobs)
  • Identify sections that are unchanged
  • Produce a change summary:
## Change Summary: [GDD filename]
Date of revision: [today]

Changed sections:
- [Section name]: [what changed — new rule, removed rule, formula modified, etc.]

Unchanged sections:
- [Section name]

Key changes affecting architecture:
- [Change 1 — likely to affect ADRs]
- [Change 2]

4. Load Architecture Inputs

Read all ADRs in docs/architecture/:

  • For each ADR, read the full file
  • Extract the "GDD Requirements Addressed" table
  • Note which GDD documents and requirement IDs each ADR references

Read docs/architecture/architecture-traceability.md if it exists.

Read the full file on GitHub · 241 lines

Files

What ships with it

1 file 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. 9d ago First seen · 241 lines · 44 tokens per session scan A 93e1f303c853

Subscribe to this mod's changes

propagate-design-change is a skill published in the GitHub repository frabcd/codex-ai-game-studio (9 stars, last pushed 2d ago), licensed MIT. It adds 44 tokens to every session and 2,020 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 2026-08-31.

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