A Chrome extension that puts a conversational AI assistant in your browser's side panel. Chat with AI models, search the web, and extract page content — all without leaving your current tab.
- Side Panel Chat — Click the extension icon to open an AI chat in the browser side panel
- Streaming Responses — Real-time streaming output with Markdown rendering (code blocks, tables, lists, etc.)
- Page Context — Read the current tab's page content as context for your message. The text is extracted from the page body (HTML/CSS/JS tags stripped), displayed as a compact widget showing the page's favicon and title, and automatically included in the user message sent to the model
- Selected Text Context — Highlight text on any page to automatically capture it as message context; new selections replace previous ones so only the latest selected snippet is used
- Document Context Upload — Upload one local document (
.txt,.md,.doc,.docx, max 2MB), extract readable text, and include it as additional context in your next user message - Web Search — Built-in Tavily search tool for real-time web information
- Page Extraction — Extract and read full content from any web page URL via the Tavily tool
- Reasoning Mode — Toggle "Thinking" to enable extended reasoning for complex tasks
- Configurable — Choose any model available on OpenRouter, configure API keys in the options page
- Copy Messages — One-click copy of raw Markdown content from assistant responses
- Node.js 18+
- pnpm (recommended) or npm
pnpm installpnpm devLoad the extension from build/chrome-mv3-dev in Chrome:
- Open
chrome://extensions - Enable "Developer mode"
- Click "Load unpacked" and select the
build/chrome-mv3-devfolder
pnpm buildThe production bundle will be in build/chrome-mv3-prod.
Click the ⚙️ settings icon in the side panel header (or right-click the extension icon → Options) to configure:
LLM Providers
- OpenRouter API Key — Required. Get one at openrouter.ai/settings/keys
- Model ID — Default:
stepfun/step-3.5-flash:free. Browse models at openrouter.ai/models
Tools
- Tavily API Key — Optional. Enables web search and page extraction. Get one at app.tavily.com
- No product account required — You can use Sidepanel Agent directly with your own provider API keys, without registering or logging into a separate Sidepanel Agent account.
- Chrome account-level sync — API keys and model settings are stored in
chrome.storage.sync, so your configuration follows your signed-in Chrome profile across devices. - No repeated setup on new devices — When you switch to another device with the same Chrome account, your previously configured keys and settings are automatically available.
- Plasmo — Chrome Extension framework
- React 18 — UI library
- Tailwind CSS + shadcn/ui — Styling and components
- OpenAI SDK — LLM API client (via OpenRouter)
- Marked — Markdown parser
- Lucide React — Icons