building-ai-chat

# AI Chat Interface Components

## Purpose

Define the emerging standards for AI/human conversational interfaces in the 2024-2025 AI integration boom. This skill leverages meta-knowledge from building WITH Claude to establish definitive patterns for streaming UX, context management, and multi-modal interactions. As the industry lacks established patterns, this provides the reference implementation others will follow.

## When to Use

Activate this skill when:
- Building ChatGPT-style conversational interfaces
- Creating AI assistants, copilots, or chatbots
- Implementing streaming text responses with markdown
- Managing conversation context and token limits
- Handling multi-modal inputs (text, images, files, voice)
- Dealing with AI-specific errors (hallucinations, refusals, limits)
- Adding feedback mechanisms (thumbs, regeneration, editing)
- Implementing conversation branching or threading
- Visualizing tool/function calling

## Quick Start

Minimal AI chat interface in under 50 lines:

```tsx
import { useChat } from 'ai/react';

export function MinimalAIChat() {
  const { messages, input, handleInputChange, handleSubmit, isLoading, stop } = useChat();

  return (
    <div className="chat-container">
      <div className="messages">
        {messages.map(m => (
          <div key={m.id} className={`message ${m.role}`}>
            <div className="content">{m.content}</div>
          </div>
        ))}
        {isLoading && <div className="thinking">AI is thinking...</div>}
      </div>

      <form onSubmit={handleSubmit} className="input-form">
        <input
          value={input}
          onChange={handleInputChange}
          placeholder="Ask anything..."
          disabled={isLoading}
        />
        {isLoading ? (
          <button type="button" onClick={stop}>Stop</button>
        ) : (
          <button type="submit">Send</button>
        )}
      </form>
    </div>
  );
}
```

For complete implementation with streaming markdown, see `examples/basic-chat.tsx`.

## Core Components

### Message Display

Build user, AI, and system message bubbles with streaming support:

```tsx
// User message
<div className="message user">
  <div className="content">{message.content}</div>
  <time className="timestamp">{formatTime(message.timestamp)}</time>
</div>

// AI message with streaming
<div className="message ai">
  <Streamdown className="content">{message.content}</Streamdown>
  {message.isStreaming && <span className="cursor">▊</span>}
</div>

// System message
<div className="message system">
  <Icon type="info" />
  <span>{message.content}</span>
</div>
```

For markdown rendering, code blocks, and formatting details, see `references/message-components.md`.

### Input Components

Create rich input experiences with attachments and voice:

```tsx
<div className="input-container">
  <button onClick={attachFile} aria-label="Attach file">
    <PaperclipIcon />
  </button>

  <textarea
    value={input}
    onChange={handleChange}
    onKeyDown={handleKeyDown}
    placeholder="Type a message..."
    rows={1}
    style={{ height: textareaHeight }}
  />

  <button onClick={toggleVoice} aria-label="Voice input">
    <MicIcon />
  </button>

  <button type="submit" disabled={!input.trim() || isLoading}>
    <SendIcon />
  </button>
</div>
```

### Response Controls

Essential controls for AI responses:

```tsx
<div className="response-controls">
  {isStreaming && (
    <button onClick={stop} className="stop-btn">
      Stop generating
    </button>
  )}

  {!isStreaming && (
    <>
      <button onClick={regenerate} aria-label="Regenerate response">
        <RefreshIcon /> Regenerate
      </button>
      <button onClick={continueGeneration} aria-label="Continue">
        Continue
      </button>
      <button onClick={editMessage} aria-label="Edit message">
        <EditIcon /> Edit
      </button>
    </>
  )}
</div>
```

### Feedback Mechanisms

Collect user feedback to improve AI responses:

```tsx
<div className="feedback-controls">
  <button
    onClick={() => sendFeedback('positive')}
    aria-label="Good response"
    className={feedback === 'positive' ? 'selected' : ''}
  >
    <ThumbsUpIcon />
  </button>

  <button
    onClick={() => sendFeedback('negative')}
    aria-label="Bad response"
    className={feedback === 'negative' ? 'selected' : ''}
  >
    <ThumbsDownIcon />
  </button>

  <button onClick={copyToClipboard} aria-label="Copy">
    <CopyIcon />
  </button>

  <button onClick={share} aria-label="Share">
    <ShareIcon />
  </button>
</div>
```

## Streaming & Real-Time UX

Progressive rendering of AI responses requires special handling:

```tsx
// Use Streamdown for AI streaming (handles incomplete markdown)
import { Streamdown } from '@vercel/streamdown';

// Auto-scroll management
useEffect(() => {
  if (shouldAutoScroll()) {
    messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
  }
}, [messages]);

// Smart auto-scroll heuristic
function shouldAutoScroll() {
  const threshold = 100; // px from bottom
  const isNearBottom =
    container.scrollHeight - container.scrollTop - container.clientHeight < threshold;
  const userNotReading = !hasUserScrolledUp && !isTextSelected;
  return isNearBottom && userNotReading;
}
```

For complete streaming patterns, auto-scroll behavior, and stop generation, see `references/streaming-ux.md`.

## Context Management

Communicate token limits clearly to users:

```tsx
// User-friendly token display
function TokenIndicator({ used, total }) {
  const percentage = (used / total) * 100;
  const remaining = total - used;

  return (
    <div className="token-indicator">
      <div className="progress-bar">
        <div className="progress-fill" style={{ width: `${percentage}%` }} />
      </div>
      <span className="token-text">
        {percentage > 80
          ? `⚠️ About ${Math.floor(remaining / 250)} messages left`
          : `${Math.floor(remaining / 250)} pages of conversation remaining`}
      </span>
    </div>
  );
}
```

For summarization strategies, conversation branching, and organization, see `references/context-management.md`.

## Multi-Modal Support

Handle images, files, and voice inputs:

```tsx
// Image upload with preview
function ImageUpload({ onUpload }) {
  return (
    <div
      className="upload-zone"
      onDrop={handleDrop}
      onDragOver={preventDefault}
    >
      <input
        type="file"
        accept="image/*"
        onChange={handleFileSelect}
        multiple
        hidden
        ref={fileInputRef}
      />
      {previews.map(preview => (
        <img key={preview.id} src={preview.url} alt="Upload preview" />
      ))}
    </div>
  );
}
```

For complete multi-modal patterns including voice and screen sharing, see `references/multi-modal.md`.

## Error Handling

Handle AI-specific errors gracefully:

```tsx
// Refusal handling
if (response.type === 'refusal') {
  return (
    <div className="error refusal">
      <Icon type="info" />
      <p>I cannot help with that request.</p>
      <details>
        <summary>Why?</summary>
        <p>{response.reason}</p>
      </details>
      <p>Try asking: {response.suggestion}</p>
    </div>
  );
}

// Rate limit communication
if (error.code === 'RATE_LIMIT') {
  return (
    <div className="error rate-limit">
      <p>Please wait {error.retryAfter} seconds</p>
      <CountdownTimer seconds={error.retryAfter} onComplete={retry} />
    </div>
  );
}
```

For comprehensive error patterns, see `references/error-handling.md`.

## Tool Usage Visualization

Show when AI is using tools or functions:

```tsx
function ToolUsage({ tool }) {
  return (
    <div className="tool-usage">
      <div className="tool-header">
        <Icon type={tool.type} />
        <span>{tool.name}</span>
        {tool.status === 'running' && <Spinner />}
      </div>
      {tool.status === 'complete' && (
        <details>
          <summary>View details</summary>
          <pre>{JSON.stringify(tool.result, null, 2)}</pre>
        </details>
      )}
    </div>
  );
}
```

For function calling, code execution, and web search patterns, see `references/tool-usage.md`.

## Implementation Guide

### Recommended Stack

Primary libraries (validated November 2025):

```bash
# Core AI chat functionality
npm install ai @ai-sdk/react @ai-sdk/openai

# Streaming markdown rendering
npm install @vercel/streamdown

# Syntax highlighting
npm install react-syntax-highlighter

# Security for LLM outputs
npm install dompurify
```

### Performance Optimization

Critical for smooth streaming:

```tsx
// Memoize message rendering
const MemoizedMessage = memo(Message, (prev, next) =>
  prev.content === next.content && prev.isStreaming === next.isStreaming
);

// Debounce streaming updates
const debouncedUpdate = useMemo(
  () => debounce(updateMessage, 50),
  []
);

// Virtual scrolling for long conversations
import { VariableSizeList } from 'react-window';
```

For detailed performance patterns, see `references/streaming-ux.md`.

### Security Considerations

Always sanitize AI outputs:

```tsx
import DOMPurify from 'dompurify';

function SafeAIContent({ content }) {
  const sanitized = DOMPurify.sanitize(content, {
    ALLOWED_TAGS: ['p', 'br', 'strong', 'em', 'code', 'pre', 'blockquote', 'ul', 'ol', 'li'],
    ALLOWED_ATTR: ['class']
  });

  return <Streamdown>{sanitized}</Streamdown>;
}
```

### Accessibility

Ensure AI chat is usable by everyone:

```tsx
// ARIA live regions for screen readers
<div role="log" aria-live="polite" aria-relevant="additions">
  {messages.map(msg => (
    <article key={msg.id} role="article" aria-label={`${msg.role} message`}>
      {msg.content}
    </article>
  ))}
</div>

// Loading announcements
<div role="status" aria-live="polite" className="sr-only">
  {isLoading ? 'AI is responding' : ''}
</div>
```

For complete accessibility patterns, see `references/accessibility.md`.

## Bundled Resources

### Scripts (Token-Free Execution)

- Run `scripts/parse_stream.js` to parse incomplete markdown during streaming
- Run `scripts/calculate_tokens.py` to estimate token usage and context limits
- Run `scripts/format_messages.js` to format message history for export

### References (Progressive Disclosure)

- `references/streaming-patterns.md` - Complete streaming UX patterns
- `references/context-management.md` - Token limits and conversation strategies
- `references/multimodal-input.md` - Image, file, and voice handling
- `references/feedback-loops.md` - User feedback and RLHF patterns
- `references/error-handling.md` - AI-specific error scenarios
- `references/tool-usage.md` - Visualizing function calls and tool use
- `references/accessibility-chat.md` - Screen reader and keyboard support
- `references/library-guide.md` - Detailed library documentation
- `references/performance-optimization.md` - Streaming performance patterns

### Examples

- `examples/basic-chat.tsx` - Minimal ChatGPT-style interface
- `examples/streaming-chat.tsx` - Advanced streaming with memoization
- `examples/multimodal-chat.tsx` - Images and file uploads
- `examples/code-assistant.tsx` - IDE-style code copilot
- `examples/tool-calling-chat.tsx` - Function calling visualization

### Assets

- `assets/system-prompts.json` - Curated prompts for different use cases
- `assets/message-templates.json` - Pre-built message components
- `assets/error-messages.json` - User-friendly error messages
- `assets/themes.json` - Light, dark, and high-contrast themes

## Design Token Integration

All visual styling uses the design-tokens system:

```css
/* Message bubbles use design tokens */
.message.user {
  background: var(--message-user-bg, var(--color-primary));
  color: var(--message-user-text, var(--color-white));
  padding: var(--message-padding, var(--spacing-md));
  border-radius: var(--message-border-radius, var(--radius-lg));
}

.message.ai {
  background: var(--message-ai-bg, var(--color-gray-100));
  color: var(--message-ai-text, var(--color-text-primary));
}
```

See `skills/design-tokens/` for complete theming system.

## Key Innovations

This skill provides industry-first solutions for:

- **Memoized streaming rendering** - 10-50x performance improvement
- **Intelligent auto-scroll** - User activity-aware scrolling
- **Token metaphors** - User-friendly context communication
- **Incomplete markdown handling** - Graceful partial rendering
- **RLHF patterns** - Effective feedback collection
- **Conversation branching** - Non-linear conversation trees
- **Multi-modal integration** - Seamless file/image/voice handling
- **Accessibility-first** - Built-in screen reader support

## Strategic Importance

This is THE most critical skill because:

1. **Perfect timing** - Every app adding AI (2024-2025 boom)
2. **No standards exist** - Opportunity to define patterns
3. **Meta-advantage** - Building WITH Claude = intimate UX knowledge
4. **Unique challenges** - Streaming, context, hallucinations all new
5. **Reference implementation** - Can become the standard others follow

Master this skill to lead the AI interface revolution.