The central hub of the YAML-driven UI platform. Parses YAML component specs and generates live HTML preview pages using the Juris.js reactive runtime — no build step, no compilation. Components are interpreted directly in the browser.
Stack: Node.js · ES modules · Juris.js runtime · Hono · MCP SDK
Port: 3005 (REST + runtime file serving)
generate_preview — generates a live HTML page from a YAML spec; runs in the browser via runtime interpretationvalidate_yaml — validates YAML syntax before preview generationjuris://manifest — server capabilitiesjuris://components — full component registry (60+ components)juris://labels — text substitution dictionaryjuris://help — usage documentationjuris://runtime/* — individual runtime JS files served on demand60+ components across 5 namespaces:
| Namespace | Focus |
|---|---|
ds |
Design system primitives |
md |
Material Design 3 components |
layout |
Page and grid structures |
marketing |
Landing page / content blocks |
system |
Utility and meta components |
Juris is the prototyping layer. Where Lit and Stencil require a compilation pipeline, Juris gives immediate visual feedback from a YAML spec — critical for rapid iteration. The runtime files it serves at /runtime/{filename} are also consumed by the preview pages generated by the other servers.
Also used as the underlying runtime for sudoku-juris, the standalone proof-of-concept that validated Juris as a capable reactive runtime outside the YAML platform context.
See research-yaml-platform for platform architecture.