viyan-mcp: Skill for Claude Code

.agents/skills/ui-widgets/SKILL.md

nitrostack-ui-widgets is a skill for Claude Code, Codex from nekhss/viyan-mcp. It costs 44 tokens per session (1,825 once invoked), scanned A, a copy of nitrostack-ui-widgets, MIT.

An agent focused on developing and maintaining document-extraction pipelines, which convert files such as documents into usable text or structured results. It covers format detection, extractor selection, fallbacks, caching, and safety limits.

In plain words
What is it for?
Use it when adding file-format support, changing extractors, improving fallback behavior, updating MIME detection, or testing document extraction code.
Why use it?
It helps ensure new formats and extractors fit the existing pipeline and that unsafe or malformed files are handled safely.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is nekhss/viyan-mcp's own configuration. It tells Claude Code and Codex how to work on viyan-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything viyan-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to nekhss/viyan-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/nekhss/viyan-mcp/main/.agents/skills/ui-widgets/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/nekhss/viyan-mcp

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for nitrostack-ui-widgets

README.md
[![agentmods](https://agentmods.dev/badge/skills/nekhss/viyan-mcp/ui-widgets/github.svg)](https://agentmods.dev/skills/nekhss/viyan-mcp/ui-widgets)
Your own site
<a href="https://agentmods.dev/skills/nekhss/viyan-mcp/ui-widgets"><img src="https://agentmods.dev/badge/skills/nekhss/viyan-mcp/ui-widgets/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for nitrostack-ui-widgets

Your own site · 80×15
<a href="https://agentmods.dev/skills/nekhss/viyan-mcp/ui-widgets"><img src="https://agentmods.dev/badge/skills/nekhss/viyan-mcp/ui-widgets.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,825 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod 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 5.1 $0.00044 $0.01825
Opus 5 $0.00022 $0.00912
Sonnet 5 $0.00009 $0.00365
Haiku 4.5 $0.00004 $0.00183

Measured 8d ago against content hash 520eb0d1d09a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

nitrostack-ui-widgets 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 8d 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.

Origin

This is a copy

100% identical to nitrostack-ui-widgets — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/ui-widgets/SKILL.md · 252 lines

How it starts

The opening of the file, as written. The whole thing — 252 lines — stays where its author put it; the contents beside it link to each section on GitHub.

When to Use

Use this skill when designing, building, or modifying interactive user interface widgets that display custom React content inside AI clients or NitroStudio.


1. Backend Definition (@Widget)

To display a React-based widget for a tool's output, decorate the tool method with @Widget.

Options:

  • String Route: A simple string representing the route identifier in the frontend React app (e.g. 'product-card').
  • Object Route: Object including:
    • route (required): The route path.
    • domain (optional): Allowed sandbox domain.
    • csp (optional): Content Security Policy guidelines.

Example:

import { Tool, Widget, z } from '@nitrostack/core';

export class CatalogTools {
  @Tool({
    name: 'fetch_product',
    description: 'Get product information by barcode.',
    inputSchema: z.object({ barcode: z.string() }),
  })
  @Widget('product-details') // Maps to the "product-details" frontend component
  async fetchProduct(input: { barcode: string }) {
    return {
      name: 'Super Nitro Energy Drink',
      price: 2.99,
      sku: input.barcode,
    };
  }
}

2. Frontend React Widget (@nitrostack/widgets)

In your React widget frontend application (typically a Next.js client component), use the useWidgetSDK hook to receive input data from the client host.

React Component Example:

'use client';

import React from 'react';
import { useWidgetSDK } from '@nitrostack/widgets';

interface ProductData {
  name: string;
  price: number;
  sku: string;
}

export default function ProductDetailsWidget() {
  const { isReady, getToolOutput, theme } = useWidgetSDK();
  const data = getToolOutput<ProductData>();

  if (!isReady) {
    return <div className="loading">Connecting to host...</div>;
  }

  if (!data) {
    return <div className="error">No product data received.</div>;
  }

  return (
    <div className={`product-card ${theme === 'dark' ? 'dark' : 'light'}`}>
      <h3>{data.name}</h3>
      <p className="price">${data.price.toFixed(2)}</p>
      <span className="sku">SKU: {data.sku}</span>
    </div>
  );
}

Read the full file on GitHub · 252 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. 8d ago First seen · 252 lines · 44 tokens per session scan A 520eb0d1d09a

Subscribe to this mod's changes

nitrostack-ui-widgets is a skill published in the GitHub repository nekhss/viyan-mcp (0 stars, last pushed 1mo ago), licensed MIT. It adds 44 tokens to every session and 1,825 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to nitrostack-ui-widgets, differing in 0 lines, and is treated as a copy.

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