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>