react

A React renderer for json-render, a system that describes user interfaces as JSON data. It turns those JSON descriptions into React components using a component registry and defined property rules.

In plain words
What is it for?
Use it to build React interfaces from JSON specifications, define reusable component catalogs, validate component properties, and render generated UI structures.
Why use it?
It avoids writing each interface directly by hand when the UI is represented as JSON. The catalog and registry define which components can be created and how they should be rendered.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/vercel-labs/json-render/react
Any agent
npx skills add vercel-labs/json-render --skill react
Clone the repo
git clone --depth 1 https://github.com/vercel-labs/json-render

Made for: Claude Code, Codex.

Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,667 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00041 $0.02667
Opus 5 $0.00020 $0.01333
Sonnet 5 $0.00008 $0.00533
Haiku 4.5 $0.00004 $0.00267

Measured 2d ago against content hash 15c1ccc5f776, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/react/SKILL.md · 299 lines

How it starts

The opening of the file, as written. The whole thing — 299 lines — stays where its author put it; the contents beside it link to each section on GitHub.

@json-render/react

React renderer that converts JSON specs into React component trees.

Quick Start

import { defineRegistry, Renderer } from "@json-render/react";
import { catalog } from "./catalog";

const { registry } = defineRegistry(catalog, {
  components: {
    Card: ({ props, children }) => <div>{props.title}{children}</div>,
  },
});

function App({ spec }) {
  return <Renderer spec={spec} registry={registry} />;
}

Creating a Catalog

import { defineCatalog } from "@json-render/core";
import { schema } from "@json-render/react/schema";
import { defineRegistry } from "@json-render/react";
import { z } from "zod";

// Create catalog with props schemas
export const catalog = defineCatalog(schema, {
  components: {
    Button: {
      props: z.object({
        label: z.string(),
        variant: z.enum(["primary", "secondary"]).nullable(),
      }),
      description: "Clickable button",
    },
    Card: {
      props: z.object({ title: z.string() }),
      slots: ["default"],
      description: "Card container with title",
    },
    Layout: {
      props: z.object({}),
      slots: ["default", "header", "footer"],
      description: "Layout with named content regions",
    },
  },
});

// Define component implementations with type-safe props
const { registry } = defineRegistry(catalog, {
  components: {
    Button: ({ props }) => (
      <button className={props.variant}>{props.label}</button>
    ),
    Card: ({ props, children }) => (
      <div className="card">
        <h2>{props.title}</h2>
        {children}
      </div>
    ),
    Layout: ({ children, slots }) => (
      <div>
        <header>{slots?.header}</header>
        <main>{children}</main>
        <footer>{slots?.footer}</footer>
      </div>
    ),
  },
});

Spec Structure (Element Tree)

The React schema uses an element tree format:

{
  "root": {
    "type": "Card",
    "props": { "title": "Hello" },
    "children": [{ "type": "Button", "props": { "label": "Click me" } }]
  }
}

Read the full file on GitHub · 299 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 299 lines · 41 tokens per session scan A 15c1ccc5f776

Subscribe to this mod's changes

react is a skill published in the GitHub repository vercel-labs/json-render (16,056 stars, last pushed 4d ago), licensed Apache-2.0. It adds 41 tokens to every session and 2,667 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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