An embeddable, lightweight chat widget that brings AI-powered conversations to any website. Built with Lit web components for maximum compatibility and minimal bundle size.

⚠️ Always use a limited-scope API key for the widget. The API key is visible in client-side code, so it should have restricted permissions and rate limits. Never use admin or full-access keys.

• 🚀 Lightweight - ~100-150kb gzipped bundle
• 🎨 Fully Customizable - Colors, branding, and styling
• 📱 Responsive - Desktop popup, mobile fullscreen
• 🔒 Shadow DOM Isolation - No style conflicts with your site
• 💬 Real-time Streaming - Server-sent events (SSE) for fast responses
• 🌐 Two Deployment Modes - Cloud CDN or self-hosted
• ♿ Markdown Support - Rich text formatting in responses
• 💾 Session Persistence - Conversations survive page reloads
• 🎯 Two Display Modes - Floating launcher or inline embed

Add these two lines to your website:

<!-- Load the widget -->
<script type="module" src="https://cdn.onyx.app/widget/1.0/dist/onyx-widget.js"></script>

<!-- Configure and display -->
<onyx-chat-widget
  backend-url="https://cloud.onyx.app/api"
  api-key="your_api_key_here"
  mode="launcher"
>
</onyx-chat-widget>

That's it! The widget will appear as a floating button in the bottom-right corner.

┌─────────────────────────────────────────┐
│         Customer Website                │
│  ┌───────────────────────────────────┐  │
│  │  <onyx-chat-widget>               │  │
│  │  (Web Component)                  │  │
│  │  ┌─────────────────────────────┐  │  │
│  │  │    Shadow DOM               │  │  │
│  │  │  • Isolated styles          │  │  │
│  │  │  • UI components            │  │  │
│  │  │  • Message history          │  │  │
│  │  └─────────────────────────────┘  │  │
│  └───────────────────────────────────┘  │
└──────────────┬──────────────────────────┘
               │ API Calls (SSE)
               ▼
┌──────────────────────────────────────────┐
│         Onyx Backend                     │
│  • POST /api/chat/create-chat-session    │
│  • POST /api/chat/send-chat-message      │
│  • Streams responses via SSE             │
└──────────────────────────────────────────┘

• Frontend Framework: Lit - Lightweight web components
• Markdown Rendering: marked.js
• Build Tool: Vite
• Styling: CSS-in-JS with Shadow DOM isolation
• API Communication: Fetch API with SSE (Server-Sent Events)

<onyx-chat-widget>
  └─ Shadow DOM
      ├─ Launcher Button (mode="launcher" only)
      └─ Chat Container
          ├─ Header
          │   ├─ Logo/Avatar
          │   ├─ Agent Name
          │   └─ Actions (Reset, Close)
          ├─ Disclaimer
          ├─ Messages
          │   ├─ User Messages
          │   ├─ Assistant Messages (with markdown)
          │   └─ Typing Indicator
          └─ Input Area
              ├─ Text Input
              ├─ Send Button
              └─ "Powered by Onyx" Footer

Note: For cloud deployment, these must be provided as HTML attributes. For self-hosted deployment, they can be set in .env file during build and will be baked into the bundle.

Note: These attributes must be provided as HTML attributes. Only backend-url and api-key can optionally be set via environment variables for self-hosted builds.

Basic Setup:

<onyx-chat-widget backend-url="https://cloud.onyx.app/api" api-key="on_abc123">
</onyx-chat-widget>

Full Customization:

<onyx-chat-widget
  backend-url="https://cloud.onyx.app/api"
  api-key="on_abc123"
  agent-id="42"
  agent-name="Support Bot"
  logo="https://yoursite.com/logo.png"
  primary-color="#FF6B35"
  background-color="#FFFFFF"
  text-color="#1A1A1A"
  mode="launcher"
>
</onyx-chat-widget>

Inline Mode (Embedded):

<div style="width: 400px; height: 600px;">
  <onyx-chat-widget
    backend-url="https://cloud.onyx.app/api"
    api-key="on_abc123"
    mode="inline"
  >
  </onyx-chat-widget>
</div>

A floating button appears in the bottom-right corner. Clicking it opens a chat popup.

• Desktop: 400x600px popup above the button
• Mobile (<768px): Full-screen overlay

<onyx-chat-widget mode="launcher"></onyx-chat-widget>

The widget is embedded directly in your page layout. Perfect for dedicated support pages.

<div class="chat-container">
  <onyx-chat-widget mode="inline"></onyx-chat-widget>
</div>

CSS Tip: The widget will fill its container's dimensions in inline mode.

• Bun 1.3+
• Access to Onyx backend API

Dependencies for widget/ are managed by the root bun workspace, so install once at the repo root:

# From the repo root
bun install

Then, from widget/:

# Copy example env file (for self-hosted builds)
cp .env.example .env

bun run dev

Opens at http://localhost:5173 with hot module replacement.

# Cloud deployment (no config baked in)
bun run build:cloud

# Self-hosted deployment (config from .env)
bun run build:self-hosted

# Standard build (same as cloud)
bun run build

widget/
├── src/
│   ├── index.ts                 # Entry point
│   ├── widget.ts                # Main component
│   ├── config/
│   │   ├── config.ts            # Configuration resolver
│   │   └── build-config.ts      # Build-time config injection
│   ├── services/
│   │   ├── api-service.ts       # API client (SSE streaming)
│   │   └── stream-parser.ts     # SSE packet processor
│   ├── types/
│   │   ├── api-types.ts         # Backend packet types
│   │   └── widget-types.ts      # Widget configuration types
│   ├── styles/
│   │   ├── theme.ts             # Design tokens
│   │   ├── colors.ts            # Color system
│   │   └── widget-styles.ts     # Component styles
│   ├── utils/
│   │   └── storage.ts           # Session persistence
│   └── assets/
│       └── logo.ts              # Default Onyx logo (base64)
├── dist/                        # Build output
├── index.html
├── package.json
├── vite.config.ts
└── tsconfig.json

• src/widget.ts - Main Lit component with all UI logic
• src/services/api-service.ts - Handles API calls and SSE streaming
• src/styles/widget-styles.ts - All CSS styles
• vite.config.ts - Build configuration (cloud vs self-hosted)

The widget communicates with these Onyx backend endpoints:

POST /chat/create-chat-session
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY

{
  "persona_id": 42  // Optional agent ID
}

Response:
{
  "chat_session_id": "uuid-here"
}

POST /chat/send-chat-message
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY

{
  "message": "User's question",
  "chat_session_id": "uuid-here",
  "parent_message_id": 123,  // null for first message
  "origin": "widget",
  "include_citations": false
}

Response: Server-Sent Events stream
{"type": "message_start"}
{"type": "message_delta", "content": "Hello"}
{"type": "message_delta", "content": " world!"}
{"type": "stop"}

1. Create .env file:

   VITE_WIDGET_BACKEND_URL=https://your-backend.com
   VITE_WIDGET_API_KEY=your_api_key

2. Build with config baked in:

   bun run build:self-hosted

3. Deploy dist/onyx-widget.js to your server

4. Customer embed:

   <script type="module" src="https://your-cdn.com/onyx-widget.js"></script>
   <onyx-chat-widget
     agent-id="1"
     agent-name="Support"
     logo="https://path-to-your-logo.com/"
   >
   </onyx-chat-widget>

The widget uses CSS custom properties (CSS variables) for theming. All styles are scoped within Shadow DOM to prevent conflicts.

Default Colors (aligned with web/src/app/css/colors.css):

--theme-primary-05: #1c1c1c; /* Buttons, accents (onyx-ink-95) */
--theme-primary-06: #000000; /* Hover state (onyx-ink-100) */
--background-neutral-00: #ffffff; /* Widget background (grey-00) */
--background-neutral-03: #e6e6e6; /* Background hover (grey-10) */
--text-04: #000000bf; /* Text (alpha-grey-100-75) */
--text-light-05: #ffffff; /* White text on dark (grey-00) */
--border-01: #00000033; /* Borders (alpha-grey-100-20) */

Override via attributes:

<onyx-chat-widget
  primary-color="#FF6B35"
  background-color="#FFFFFF"
  text-color="#1A1A1A"
>
</onyx-chat-widget>

• ✅ Chrome/Edge 90+ (Chromium)
• ✅ Firefox 90+
• ✅ Safari 15+
• ✅ Mobile Safari (iOS 15+)
• ✅ Mobile Chrome (Android)

Requirements:

• ES Modules support
• Custom Elements v1
• Shadow DOM v1
• Fetch API with SSE

• Bundle Size: ~100-150kb gzipped
• Initial Load: Shadow DOM renders immediately
• Message Latency: Real-time SSE streaming (<100ms first token)
• Session Persistence: sessionStorage (auto-save on each message)