Multi-Surface Rendering with json-render

Define once, render everywhere. A single json-render catalog and spec can produce React web UIs, PDF reports, HTML emails, Remotion demo videos, and OG images — each surface gets its own registry that maps catalog types to platform-native components.

Quick Reference

Total: 5 rules across 5 categories

How Multi-Surface Rendering Works

1. One catalog — Zod-typed component definitions shared across all surfaces
2. One spec — flat-tree JSON/YAML describing the UI structure
3. Many registries — each surface maps catalog types to its own component implementations
4. Many renderers — each package renders the spec using its registry

The catalog is the contract. The spec is the data. The registry is the platform-specific implementation.

Quick Start — Same Catalog, Different Renderers

Shared Catalog (used by all surfaces)

import { defineCatalog } from '@json-render/core'
import { schema } from '@json-render/react/schema'
import { z } from 'zod'

export const catalog = defineCatalog(schema, {
  components: {
    Heading: {
      props: z.object({
        text: z.string(),
        level: z.enum(['h1', 'h2', 'h3']),
      }),
      children: false,
    },
    Paragraph: {
      props: z.object({ text: z.string() }),
      children: false,
    },
    StatCard: {
      props: z.object({
        label: z.string(),
        value: z.string(),
        trend: z.enum(['up', 'down', 'flat']).optional(),
      }),
      children: false,
    },
  },
})

Render to Web (React)

import { Renderer } from '@json-render/react'
import { webRegistry } from './registries/web'

// webRegistry comes from `defineRegistry(catalog, { components })`.
// RendererProps is { spec, registry, loading?, fallback? } — no catalog prop.
export const Dashboard = ({ spec }) => (
  <Renderer spec={spec} registry={webRegistry} />
)

Render to PDF

import { renderToBuffer, renderToFile } from '@json-render/react-pdf'
import { pdfRegistry } from './registries/pdf'

// Buffer for HTTP response. PDF options are { registry?, state?, handlers? }.
// includeStandard is an EMAIL option, not a PDF one (see references/upstream-pdf.md).
const buffer = await renderToBuffer(spec, { registry: pdfRegistry })

// Direct file output — renderToFile(spec, filePath, options?)
await renderToFile(spec, './output/report.pdf', { registry: pdfRegistry })

Render to Email

import { renderToHtml } from '@json-render/react-email'
import { emailRegistry } from './registries/email'

const html = await renderToHtml(spec, { registry: emailRegistry })
await sendEmail({ to: user.email, subject: 'Weekly Report', html })

Render to OG Image (Satori)

import { renderToSvg, renderToPng } from '@json-render/image'
import { imageRegistry } from './registries/image'

const png = await renderToPng(spec, {
  registry: imageRegistry,
  width: 1200,
  height: 630,
})

Render to Video (Remotion)

// Verified 2026-07-31 against @json-render/remotion@0.19.0: the export is
// `Renderer` and its props are { spec, components }. fps and durationInFrames
// belong on Remotion's own Composition, not on this renderer.
import { Renderer } from '@json-render/remotion'
import { remotionComponents } from './registries/remotion'

export const DemoVideo = () => (
  <Renderer spec={spec} components={remotionComponents} />
)

Render to Terminal (Ink, 0.15+)

import { render } from 'ink'
import { Renderer } from '@json-render/ink'
import { catalog } from './catalog'
import { inkRegistry } from './registries/ink'

render(<Renderer spec={spec} catalog={catalog} registry={inkRegistry} />)

Useful for /ork:* CLI dashboards and streaming agent chat interfaces — ships 20+ Ink-native components (Box, Text, Spinner, Table, Markdown, Progress, etc.).

Render to Next.js App (0.16+)

// createNextApp lives on the /server subpath, not the package root.
import { createNextApp } from '@json-render/next/server'

const { getPageData, generateMetadata, generateStaticParams } = createNextApp({
  spec,                        // NextAppSpec: routes keyed by Next.js URL patterns
  loaders: { getPost },        // server-side data loaders referenced by route.loader
})

It does not scaffold a project on disk. createNextApp returns the server-side pieces you re-export from a catch-all route, and the page itself renders through PageRenderer:

// app/[[...slug]]/page.tsx
export { generateMetadata, generateStaticParams }

export default async function Page({ params }) {
  const data = await getPageData(params)
  if (!data) notFound()
  return <PageRenderer {...data} registry={webRegistry} />
}

A spec describes a route tree (pages, layouts, metadata, loading and error states), not just a component tree.

Decision Matrix — When to Use Each Target

All @json-render/* renderers are verified against 0.20.0 (@json-render/core). The 0.19.0 to 0.20.0 export surface went 84 to 87 symbols with zero removals, so every API documented here still resolves. 0.20.0 adds named slots (slots?: Record<string, string[]> on UIElement, with catalogs declaring slots: ["default", "header", ...]), nested repeats via an item-relative repeat.statePath of the form {"$item": "employees"}, and item-scoped visibility so a repeat plus visible: {"$item": ...} on the same element filters items instead of failing. One breaking change, which no rule in this skill uses: ActionExecutionContext.executeAction now takes an ActionBinding rather than a bare action name, which only affects hand-written custom renderer bridges.

Load rules/target-selection.md for detailed selection criteria and trade-offs.

Upstream coverage (do not restate)

This skill wraps @json-render/*. Vendor documentation is fetched, not repeated. What survives here is the house delta: references/ork-delta.md plus the five rules.

Read references/ork-delta.md before writing renderer code: it carries the API-drift rule, the Remotion and PDF latency budgets, and the PDF / React Native registry layout ceiling.

PDF Renderer — Reports and Documents

The @json-render/react-pdf package renders specs to PDF using react-pdf under the hood. Three output modes: buffer, file, and stream.

import { renderToBuffer, renderToFile, renderToStream } from '@json-render/react-pdf'

// In-memory buffer (for HTTP responses, S3 upload)
// PDF options are { registry?, state?, handlers? }, no catalog field
const buffer = await renderToBuffer(spec, { registry: pdfRegistry })
res.setHeader('Content-Type', 'application/pdf')
res.send(buffer)

// Direct file write — renderToFile(spec, filePath, options?)
await renderToFile(spec, './output/report.pdf', { registry: pdfRegistry })

// Streaming (for large documents)
const stream = await renderToStream(spec, { registry: pdfRegistry })
stream.pipe(res)

Load rules/pdf-email-renderer.md for PDF registry patterns and email rendering.

Image Renderer — OG Images and Social Cards

The @json-render/image package uses Satori to convert specs to SVG, then optionally to PNG. Designed for server-side generation of social media images.

import { renderToSvg, renderToPng } from '@json-render/image'

// SVG output (smaller, scalable)
const svg = await renderToSvg(spec, {
  registry: imageRegistry,
  width: 1200,
  height: 630,
})

// PNG output (universal compatibility)
const png = await renderToPng(spec, {
  registry: imageRegistry,
  width: 1200,
  height: 630,
})

Load rules/video-image-renderer.md for Satori constraints and Remotion composition patterns.

Registry Mapping — Same Catalog, Platform-Specific Components

Each surface needs its own registry. The registry maps catalog types to platform-specific component implementations while the catalog and spec stay identical.

// Web registry — uses HTML elements
const webRegistry = {
  Heading: ({ text, level }) => {
    const Tag = level // h1, h2, h3
    return <Tag className="font-bold">{text}</Tag>
  },
  StatCard: ({ label, value, trend }) => (
    <div className="rounded border p-4">
      <span className="text-sm text-gray-500">{label}</span>
      <strong className="text-2xl">{value}</strong>
    </div>
  ),
}

// PDF registry — uses react-pdf primitives
import { Text, View } from '@react-pdf/renderer'
const pdfRegistry = {
  Heading: ({ text, level }) => (
    <Text style={{ fontSize: level === 'h1' ? 24 : level === 'h2' ? 18 : 14 }}>
      {text}
    </Text>
  ),
  StatCard: ({ label, value }) => (
    <View style={{ border: '1pt solid #ccc', padding: 8 }}>
      <Text style={{ fontSize: 10, color: '#666' }}>{label}</Text>
      <Text style={{ fontSize: 18, fontWeight: 'bold' }}>{value}</Text>
    </View>
  ),
}

Load rules/registry-mapping.md for registry creation patterns and type safety.

Rule Details

Target Selection

Decision criteria for choosing the right renderer target.

React Renderer

Web rendering with the <Renderer> component.

PDF & Email Renderer

Server-side rendering to PDF buffers/files and HTML email strings.

Video & Image Renderer

Remotion compositions and Satori image generation.

Registry Mapping

Creating platform-specific registries for a shared catalog.

Key Decisions

Common Mistakes

1. Building separate component trees for each surface — defeats the purpose; share the catalog and spec
2. Using Puppeteer to screenshot React for PDF generation — slow, fragile; use native react-pdf rendering
3. One giant registry covering all platforms — impossible since PDF uses <View>/<Text>, web uses <div>/<span>
4. Forgetting Satori limitations — no CSS grid, limited flexbox; design image registries with these constraints
5. Duplicating catalog definitions per surface — one catalog, many registries; the catalog is the contract

Related Skills

• ork:json-render-catalog — Catalog definition patterns with Zod, shadcn components
• ork:demo-producer — Video production pipeline using Remotion
• ork:mcp-visual-output — Rendering specs in Claude/Cursor via MCP