prefab-dev-build
GitHub指导开发者如何本地构建和预览渲染器及沙盒环境的变更。通过统一命令处理 TS、Python 源码的编译打包与文档生成,避免直接运行原始 npm 命令导致的缓存或配置错误,确保本地开发与部署预览的一致性。
Trigger Scenarios
Install
npx skills add PrefectHQ/prefab --skill prefab-dev-build -g -y
SKILL.md
Frontmatter
{
"name": "prefab-dev-build",
"description": "How to build and preview renderer\/playground changes locally. Use this skill when modifying the renderer (themes, components, styles), the playground (theme picker, examples), or any Python source that needs to appear in the playground. Covers the build pipeline, common pitfalls, and how to iterate."
}
Building and Previewing Renderer/Playground Changes
The One Command
After changing renderer source, Python source, or playground code:
uv run prefab dev build-docs
This is the only command you should use. It orchestrates the full pipeline
with smart caching (only rebuilds what changed). Never run raw npm build
commands (npm run build:playground, npm run build:renderer) directly —
they skip critical steps.
What the Pipeline Does
- Renderer build (if TS source changed) —
npm run build:rendererbuilds the code-split ESM bundle for CDN delivery (the primary renderer artifact) - Python bundle generation — serializes all
src/prefab_ui/**/*.pyintorenderer/src/playground/bundle.jsonfor Pyodide - Playground build (if playground source changed) — runs Vite with
VITE_LOCAL_PLAYGROUND=1so the Python bundle is inlined - Copy to docs/ — puts built files where
prefab playgroundandmintlify devexpect them
Note: build-docs builds the CDN renderer. The bundled single-file renderer
(airgapped fallback) is built separately via prefab dev build-renderers.
Previewing
# Start the playground (serves from docs/)
uv run prefab playground
# Or start the full docs site
mintlify dev --dir docs
The playground runs on port 5174 by default.
Common Mistakes
"attempted to install wheel before downloading it" — the playground was
built without VITE_LOCAL_PLAYGROUND=1. This happens when you run
npm run build:playground directly instead of prefab dev build-docs.
Fix: run the full pipeline.
Playground shows stale Python code — bundle.json is stale. The full
pipeline regenerates it; raw npm commands don't.
Renderer changes not visible in deploy previews — deploy previews load
chunks from the CDN (@latest), not from the branch. Test renderer changes
locally.
Reference
Full build and release details: dev-docs/build-pipeline.md
Version History
- d81dce7 Current 2026-07-24 17:49


