frontpage.

I built a UI language where you describe UI as JSON, and errors are caught at compile time—not runtime.

Why: When AI generates UI, JavaScript is too flexible. You get runtime errors, implicit behavior, hard-to-debug state. Constela constrains the surface area so output is deterministic and validatable.

Side effect: 5× faster builds, 5× smaller output than Next.js (same site, measured).

Live demo (this site is built with Constela): https://constela.dev

Try it yourself: https://constela.dev/playground

Source: https://github.com/yuuichieguchi/constela

I'd be interested in feedback from people working on compilers, UI frameworks, or AI-assisted development.

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Show HN: Constela – JSON DSL for AI-generated UI with compile-time validation