@studiozandra/svelte-ai-chat-widget

A production-ready AI chatbot widget for SvelteKit with Server-Sent Events (SSE) streaming. Built with Svelte 5 runes.

Features

• 🚀 Svelte 5 Runes - Modern reactive state management
• 💬 Real-time Streaming - SSE support for responsive AI interactions
• 🎨 Fully Customizable - Themes, slots, and CSS custom properties
• 🌍 i18n Ready - All UI text exposed through props
• ⌨️ Keyboard Navigation - Escape to close, Enter to send
• 📱 Responsive Design - Works on mobile and desktop
• 🔒 Session Persistence - Resume conversations automatically
• 🪶 Lightweight - Under 50KB gzipped

Installation

npm install @studiozandra/svelte-ai-chat-widget

Quick Start

1. Run Setup CLI

The easiest way to get started is with the interactive setup:

npx svelte-ai-chat-widget setup

This will:

• ✅ Install backend API endpoints (chat send & history)
• ✅ Install database utilities (SQLite)
• ✅ Install environment config & rate limiting
• ✅ Create a demo page (optional)
• ✅ Show you next steps

2. Configure Environment

# Install required dependencies
npm install @anthropic-ai/sdk better-sqlite3 @types/better-sqlite3 better-auth

# Set up your API key
cp .env.example .env
# Add your ANTHROPIC_API_KEY to .env

3. Start Development Server

npm run dev

Visit the demo page (default: http://localhost:5173/chatbot-demo) to see it in action!

---

Manual Setup (Alternative)

If you prefer manual setup:

<script lang="ts">
  import { ChatWidget } from '@studiozandra/svelte-ai-chat-widget';
</script>

<ChatWidget
  sendMessageEndpoint="/api/chat/send"
  historyEndpoint="/api/chat/history"
  theme="light"
/>

Then copy backend files from templates/backend/ to your project.

📖 Full Backend Setup Guide →

Props

Prop	Type	Required	Description
sendMessageEndpoint	string	Yes	POST endpoint for sending messages (SSE stream)
historyEndpoint	string	Yes	GET endpoint for conversation history
context	Record<string, any>	No	Additional context sent with each request
theme	'light' | 'dark' | string	No	Built-in theme or custom CSS class
i18n	object	No	Customize UI text

i18n Options

{
  placeholder?: string;      // Default: "Type your message..."
  title?: string;           // Default: "Chat"
  sendButton?: string;      // Default: "Send"
  errorMessage?: string;    // Default: "Something went wrong"
}

Events

<ChatWidget
  {...props}
  onopen={() => console.log('Chat opened')}
  onclose={() => console.log('Chat closed')}
  onmessage={(msg) => console.log('Message:', msg)}
/>

Theming

Built-in Themes

<ChatWidget theme="light" {...props} />
<ChatWidget theme="dark" {...props} />

Custom CSS Variables

:root {
  --chat-bubble-bg: #4f46e5;
  --chat-bubble-color: white;
  --chat-window-bg: white;
  --chat-header-bg: #4f46e5;
  --chat-header-color: white;
  --chat-user-message-bg: #4f46e5;
  --chat-user-message-color: white;
  --chat-assistant-message-bg: #f3f4f6;
  --chat-input-border: #e5e7eb;
  --chat-send-button-bg: #4f46e5;
}

Slots

Custom Header

<ChatWidget {...props}>
  {#snippet header()}
    <div class="custom-header">
      <img src="/logo.png" alt="Logo" />
      <h3>Support Chat</h3>
    </div>
  {/snippet}
</ChatWidget>

Custom Footer

<ChatWidget {...props}>
  {#snippet footer()}
    <p>Your conversations are private and encrypted.</p>
  {/snippet}
</ChatWidget>

Backend API Specification

The widget requires two endpoints:

POST /api/chat/send

Request:

{
  "message": "Hello, AI!",
  "sessionId": "optional-uuid",
  "context": { "userId": "123" }
}

Response: Server-Sent Events stream

data: {"chunk": "Hello"}
data: {"chunk": " there!"}
data: {"done": true, "sessionId": "uuid"}

GET /api/chat/history

Request:

GET /api/chat/history?sessionId=uuid&limit=50&offset=0

Response:

{
  "messages": [
    {
      "id": "msg-1",
      "role": "user",
      "content": "Hello!",
      "timestamp": 1234567890000
    }
  ],
  "hasMore": false
}

📖 Complete Backend Implementation Guide →

TypeScript Support

Full TypeScript support with exported types:

import type {
  ChatWidgetProps,
  Message,
  ChatSession,
  HistoryResponse,
  SendMessageRequest
} from '@studiozandra/svelte-ai-chat-widget';

Advanced Usage

Programmatic Control

import { createChatStore } from '@studiozandra/svelte-ai-chat-widget';

const chatStore = createChatStore();

// Access state
console.log(chatStore.messages);
console.log(chatStore.isOpen);

// Control widget
chatStore.open();
chatStore.close();
chatStore.addMessage({ role: 'user', content: 'Hello' });

Browser Support

• Chrome/Edge 90+
• Firefox 88+
• Safari 14+

Security

The included backend implementation provides:

• ✅ API key security (server-side only)
• ✅ User authentication (Better Auth required)
• ✅ Session validation (user-scoped chat history)
• ✅ Rate limiting (10 req/min default)
• ✅ Input validation
• ✅ SQL injection prevention

Authentication Requirements:

• 🔒 Better Auth must be configured
• 🔒 All chat endpoints require authenticated sessions
• 🔒 Users can only access their own chat history
• 🔒 User IDs are server-verified (not client-provided)

Production recommendations:

• Use HTTPS
• Enable CORS properly
• Add content moderation
• Set up proper session management

License

MIT © studiozandra

Links

• 🐛 Report a bug
• 💡 Request a feature
• 📖 Backend Setup Guide
• 📝 Changelog