cesium-agents-skill-validator

name	cesium-agents-skill-validator
description	Use when CesiumJS code has just been generated or reviewed and must be checked before it is called done, to catch deprecated APIs and common defects, or when auditing CesiumJS code from an older source. Detects the removed synchronous patterns (readyPromise, the url constructor option, ModelExperimental, defaultValue, new on a Cartesian factory), WebGPU assumptions, missing ion tokens, missing destroy() calls, and coordinate-type mistakes. Runs a deterministic checklist and routes each failure to the skill that fixes it. Keywords: validate CesiumJS code, review Cesium code, is this Cesium code correct, deprecated CesiumJS API, readyPromise, ModelExperimental, defaultValue removed, check before commit, CesiumJS code quality, lint Cesium, did I use the right API, audit Cesium scene, why might this code fail.
license	MIT
compatibility	Designed for Claude Code. Requires CesiumJS 1.124+.
metadata	{"author":"OpenAEC-Foundation","version":"1.0"}

Cesium Agents : Skill Validator

Overview

This is a validation skill. Run it over any CesiumJS code before declaring it finished. It is a deterministic checklist: each check has a grep-style trigger, a verdict, and the skill that holds the fix. The checklist targets CesiumJS 1.124+, where a large set of pre-2023 APIs no longer exist.

CesiumJS 1.124+ is WebGL2 only. Any code that names or assumes WebGL is fine; any code that names or assumes WebGPU for CesiumJS is wrong.

When to Use

• A CesiumJS snippet was just generated and is about to be presented or committed.
• Reviewing CesiumJS code from an older tutorial, blog post, or Sandcastle.
• A scene "should work" but renders blank, throws, or leaks, and a structured pass is needed.

Check 1 : Removed Async-Era APIs (BLOCKER)

Each token below was removed before or within the 1.124 to 1.142 window. Any match is a hard failure. Verdict: REJECT until fixed.

Found token	Status	Required replacement	Fix skill
new Cesium3DTileset(	removed 1.107	await Cesium3DTileset.fromUrl(url) / .fromIonAssetId(id)	cesium-syntax-3d-tiles
.readyPromise	removed 1.107	await the async factory	cesium-core-versioning
.ready on a tileset/model/provider	removed 1.107	the awaited result is ready	cesium-core-versioning
Model.fromGltf( (without Async)	removed	Model.fromGltfAsync(	cesium-syntax-gltf-model
ModelExperimental	removed (merged into Model)	Model	cesium-syntax-gltf-model
new CesiumTerrainProvider({	removed 1.107	await CesiumTerrainProvider.fromUrl(url)	cesium-syntax-terrain
createWorldTerrain( (without Async)	removed 1.107	createWorldTerrainAsync(	cesium-syntax-terrain
defaultValue(	removed 1.134	a ?? b	cesium-core-versioning
new Cesium.Cartesian3.fromDegrees	throws since 1.139	drop new	cesium-core-coordinates
terrainExaggeration on Globe	removed 1.113	scene.verticalExaggeration	cesium-core-versioning

Check 2 : WebGPU Assumption (BLOCKER)

• Trigger: any reference to a WebGPU backend, context, or toggle for CesiumJS.
• Verdict: REJECT. CesiumJS renders only on WebGL2 in 1.124+.
• Fix skill: cesium-core-architecture.

Check 3 : Missing ion Token (BLOCKER if ion used)

• Trigger: code uses fromIonAssetId, IonImageryProvider, world imagery, world terrain, or OSM Buildings, but never sets Ion.defaultAccessToken.
• Verdict: REJECT. The scene will 401 and the globe will be blank.
• Fix skill: cesium-syntax-viewer, cesium-impl-cesium-ion.

Check 4 : Async Factory Not Awaited (BLOCKER)

• Trigger: a from* factory (fromUrl, fromIonAssetId, fromGltfAsync, fromProviderAsync) whose result is used without await.
• Verdict: REJECT. The variable holds a Promise, not the object; scene.primitives.add and property access fail.
• Fix skill: cesium-core-versioning, cesium-syntax-3d-tiles.

Check 5 : Missing Teardown (WARN)

• Trigger: a Viewer, Cesium3DTileset, Model, custom Primitive, or ScreenSpaceEventHandler is created with no destroy() on any cleanup path; or an addEventListener on a CesiumJS Event with no stored remover.
• Verdict: WARN. Acceptable for a one-shot script, a defect for an app.
• Fix skill: cesium-core-memory, cesium-errors-memory.

Check 6 : Coordinate Type and Unit (BLOCKER)

• Trigger: new Cartographic( with degree-magnitude numbers; a Cartographic assigned to entity.position; a factory called as (latitude, longitude); degrees passed to new HeadingPitchRoll.
• Verdict: REJECT. The geometry will be misplaced or absent.
• Fix skill: cesium-errors-coordinates, cesium-core-coordinates.

Check 7 : API Name Verification (BLOCKER)

• Trigger: any CesiumJS class, method, or enum value not confirmed against the API reference.
• Verdict: REJECT until verified. Hallucinated API names are the highest-risk defect in generated code.
• Action: WebFetch the name against https://cesium.com/learn/cesiumjs/ref-doc/ (the SOURCES.md primary source). If it does not exist, the code is wrong.

Check 8 : Continuous Render on a Static Scene (WARN)

• Trigger: a static or rarely-changing scene with no requestRenderMode: true.
• Verdict: WARN. Not a defect, but a battery and GPU cost.
• Fix skill: cesium-core-performance.

Verdict Rule

• Any BLOCKER unresolved : REJECT the code. Do not present it as done.
• Only WARN items : ACCEPT with the warnings stated to the user.
• All checks clear : ACCEPT.

NEVER report CesiumJS code as complete while a Check 1 to 4, 6, or 7 failure stands.

Quick Scan Order

Run Check 1, 2, 3, 4 first; they are the fastest to grep and the most common. Then Check 6 and 7. Check 5 and 8 last; they are WARN-level.

Reference Files

• references/methods.md : every check as a grep-ready pattern with verdict and fix skill.
• references/examples.md : worked validations of three code snippets, one rejected and rewritten, one warned, one accepted.
• references/anti-patterns.md : the failure modes of validation itself, such as trusting a plausible but hallucinated API name.

Related Skills

• cesium-core-versioning : the full removed-API migration detail.
• cesium-core-architecture : the WebGL2-only fact.
• cesium-errors-coordinates : coordinate type and unit failures.
• cesium-core-memory : teardown requirements.
• cesium-agents-scene-architect : the setup decisions this validator checks.

Sources

Built on the project research base (docs/research/vooronderzoek-cesium.md) and the verified CHANGES.md matrix, against the CesiumJS API Reference on the approved sources, 2026-05-20.