What is modify-scene-schema?

A workflow for changing the JSON files that store scenes, prefabs, projects, assets, or tilesets. It covers validation, defaults, loading, compatibility with older files, and tests.

Use it when adding, removing, renaming, or tightening saved fields, changing allowed data types, or changing the format version.

It prevents saved games and editor data from becoming unreadable after fields or data structures change.

How andvolodko/html5-game-editor configures Cursor

Reuse

Borrowing it

Nothing to install: this file belongs to andvolodko/html5-game-editor. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/andvolodko/html5-game-editor/master/.cursor/skills/modify-scene-schema/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/andvolodko/html5-game-editor

Made for: Cursor.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/modify-scene-schema/github.svg)](https://agentmods.dev/skills/andvolodko/html5-game-editor/modify-scene-schema)

Your own site

<a href="https://agentmods.dev/skills/andvolodko/html5-game-editor/modify-scene-schema"><img src="https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/modify-scene-schema/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/andvolodko/html5-game-editor/modify-scene-schema"><img src="https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/modify-scene-schema.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 65 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,845 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 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.

Model	Per session	Once invoked
Fable 5.1	$0.00065	$0.01845
Opus 5.5	$0.00026	$0.00738
Sonnet 5.5	$0.00013	$0.00369
Haiku 4.5	$0.00006	$0.00185

Measured 2mo ago against content hash d186a3c7947b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

modify-scene-schema 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 2mo 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.

.cursor/skills/modify-scene-schema/SKILL.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Modify Scene Schema

Strict workflow for persisted scene/project/asset formats. Prefer additive, backward-compatible changes.

Cross-package planning: .cursor/skills/architecture-change/SKILL.md. This skill is the format pipeline itself.

A new node type almost always touches this pipeline — complete .cursor/skills/add-node-type/SKILL.md as well. A new asset kind: .cursor/skills/add-asset-type/SKILL.md.

When to use this skill

Adding, renaming, removing, or tightening fields on scene/prefab/project/asset/tileset JSON.
Changing unions (ComponentData, AssetMetadata, renderer).
Old games/*/assets/**/*.json or games/*/.project/assets.json would fail parse* after the change.

Do not use this for editor-only UI prefs (EDITOR_LAYOUT_VERSION, scene-view settings) unless they are confused with scene JSON. Those live in apps/editor/src/settings/editor-settings-storage.ts.

Before changing code

Identify which document changes:

Document	Version const	Parse	Typical files
Scene	`SCENE_SCHEMA_VERSION` (`packages/scene/src/types.ts`)	`parseSceneData`	`games//assets/scenes/.json`
Prefab	`PREFAB_SCHEMA_VERSION` (`packages/scene/src/prefab/types.ts`)	`parsePrefabData`	`games//assets/prefabs//.prefab.json`
Project	`PROJECT_SCHEMA_VERSION` (`packages/project/src/types.ts`)	`parseProjectData`	`games/*/project.json`
Asset DB	`ASSET_SCHEMA_VERSION` (`packages/assets/src/types.ts`)	`parseAssetDatabase`	`games/*/.project/assets.json`
TileSet	`TILESET_SCHEMA_VERSION` (`packages/assets/src/tileset.ts`)	`parseTileSetData`	`*.tileset.json`

All of these are currently version: 1.

There is no scene/project/asset migration runner. Roadmap (docs/roadmap.md, README “Schema migrations”) still lists one. Do not invent a migrateSceneV2 API.

Compatibility today is:
- Optional fields on types/Zod.
- Parse-time defaults: packages/scene/src/scene-parse-defaults.ts (withSceneParseDefaults); parseProjectData fills missing startScene / resolution / background.
- Zod .default() on additive arrays (e.g. glTF animations).

Read the full file on GitHub · 148 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.

2mo ago First seen · 148 lines · 65 tokens per session scan A d186a3c7947b

Subscribe to this mod's changes

modify-scene-schema is a skill published in the GitHub repository andvolodko/html5-game-editor (14 stars, last pushed 1mo ago), licensed MIT. It adds 65 tokens to every session and 1,845 once invoked, about $0.0003 per session on Opus 5.5. 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.

2d 3d Game development editor game-development game-editor game-engine

modify-scene-schema next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
modify-scene-schemaandvolodko/html5-game-editor	Skill	14	1mo ago	MIT	A	65	Cursor
self-evolvetettethu/VibeGame	Skill	367	24d ago	Apache-2.0	A	50	Claude Code, Codex
artist-self-evolvetettethu/VibeGame	Skill	367	24d ago	Apache-2.0	A	62	Claude Code, Codex
vibegame-buildtettethu/VibeGame	Skill	367	24d ago	Apache-2.0	A	42	Claude Code, Codex
vibegame-starttettethu/VibeGame	Skill	367	24d ago	Apache-2.0	A	61	Claude Code, Codex
vibegame-edittettethu/VibeGame	Skill	367	24d ago	Apache-2.0	A	57	Claude Code, Codex
hearth-feelechoo19/hearth	Skill	44	1mo ago	MIT	A	97	Claude Code

html5-game-editor: Skill for Cursor