Nitrostack UI Widgets

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>
  );
}

3. State Management & Synchronization (useWidgetState)

Use useWidgetState to manage and persist client-side widget state (e.g. selected tabs, filter values, input states). This state automatically synchronizes with the host application context, persisting it across page re-renders.

Example:

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

export default function StationPanelWidget() {
  const [state, setState] = useWidgetState(() => ({
    selectedTab: 'overview',
    showExtendedInfo: false,
  }));

  return (
    <div>
      <button => setState({ ...state, selectedTab: 'alerts' })}>
        View Alerts
      </button>
      <p>Current Tab: {state?.selectedTab}</p>
    </div>
  );
}

4. Calling Core Tools from Widgets (callTool)

You can invoke other backend MCP tools directly from the frontend widget using callTool. This is useful for tool chaining or triggering detailed audits.

Example:

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

export default function SystemDiagnostics() {
  const { callTool, isReady } = useWidgetSDK();
  const [isRunning, setIsRunning] = useState(false);
  const [result, setResult] = useState<string | null>(null);

  const runDiagnostic = async () => {
    if (!isReady) return;
    setIsRunning(true);
    try {
      const response = await callTool('run_diagnostic', { system: 'oxygen_scrubber' });
      setResult(response.result as string);
    } catch (err) {
      setResult('Diagnostic execution failed.');
    } finally {
      setIsRunning(false);
    }
  };

  return (
    <button disabled={isRunning}>
      {isRunning ? 'Running...' : 'Run Diagnostics'}
    </button>
  );
}

5. Layout & Display Controls

Widgets can dynamically request size mode changes (fullscreen, inline, picture-in-picture) and adapt layouts to safe areas (dynamic islands/notches) or maximum height constraints.

Key Methods:

• requestFullscreen(): Switch host widget display to fullscreen.
• requestInline(): Switch host widget display back to inline.
• requestPip(): Float widget in Picture-in-Picture.
• requestClose(): Dismiss the widget completely.

Example:

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

export default function StatusBoard() {
  const { 
    requestFullscreen, 
    requestInline, 
    requestClose,
    displayMode,   // Reactive property ('fullscreen' | 'inline' | 'pip')
    maxHeight,     // Reactive maxHeight constraint (in pixels)
    getSafeArea    // Insets data: { top, right, bottom, left }
  } = useWidgetSDK();

  const safeArea = getSafeArea() || { top: 0, bottom: 0 };

  return (
    <div style={{ maxHeight: maxHeight || 400, paddingTop: safeArea.top }}>
      <h3>Mode: {displayMode}</h3>
      <button
      <button
      <button Widget</button>
    </div>
  );
}

6. Chat Navigation & Actions

Widgets can interact with the host chat pane using external browser links and follow-up prompts.

Key Methods:

• openExternal(url): Open the target URL safely in the user's primary external browser.
• sendFollowUpMessage(prompt): Insert a message into the chat flow, automatically submitting it to the LLM agent.

Example:

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

export default function MissionControl() {
  const { openExternal, sendFollowUpMessage } = useWidgetSDK();

  return (
    <div>
      {/* Open external documentation */}
      <button => openExternal('https://docs.nitrostack.dev')}>
        Open Manual
      </button>

      {/* Ask LLM agent directly from the widget */}
      <button => sendFollowUpMessage('Analyze mission failures from last week')}>
        Ask Agent to Analyze
      </button>
    </div>
  );
}

7. Media & Accessibility Queries

The SDK provides helper utilities to query target client capabilities for styling or accessibility.

Key Utilities:

• prefersReducedMotion(): Returns true if client settings specify reduced motion. Disable animations.
• isPrimarilyTouchDevice(): Returns true if the device has a coarse pointer (e.g. touch/mobile). Increase button target sizes.
• isHoverAvailable(): Returns true if pointer supports hover states.
• prefersDarkColorScheme(): Returns true if the system theme is dark.

Example:

import React from 'react';
import { isPrimarilyTouchDevice, prefersReducedMotion } from '@nitrostack/widgets';

export default function AccessiblePanel() {
  const isTouch = isPrimarilyTouchDevice();
  const reducedMotion = prefersReducedMotion();

  return (
    <div className={reducedMotion ? 'no-animations' : 'smooth-transitions'}>
      <button style={{ padding: isTouch ? '16px' : '8px' }}>
        Interactive Button
      </button>
    </div>
  );
}

8. Testing Widgets

• Open your project in NitroStudio for visual preview.
• Invoke the tool from the AI chat or testing pane to verify the widget updates instantly with the returned JSON structure.