Tacit: The Zero-Knowledge AI Sidebar

Chrome Web Store | Demo Video

📜 Core Philosophy

"The extension that knows nothing about you."

Most AI browser extensions follow the same playbook:

1. Collect your data (to "improve the experience")
2. Mark up AI provider costs
3. Clutter your browser with features you didn't ask for

We built Tacit differently.

Our Principles

Zero-Knowledge Privacy

• No backend servers. We don't have a database. We literally cannot see your conversations.
• Local-first storage. Your chat history and API key are encrypted in your browser local storage.
• Auditable code. Open sourced on github.

Zero-Markup Pricing

• Bring Your Own Key (BYOK). Pay wholesale rates directly to OpenRouter, OpenAI, Anthropic, or Google.
• Or pay nothing. Run Ollama or LM Studio locally with zero API costs.
• No subscription trap. We'll never gate core features behind a paywall.

Zero Clutter

• No injected buttons polluting your navigation.
• No "AI Shopping Assistant" or other gimmicks.
• Just a sidebar. Press Alt+J, ask your question, get your answer.

✨ Features

⚡ The Basics

• Global hotkey: Alt+J (or Option+J on Mac) slides the sidebar in from any webpage
• Persistent chat history: Local storage with client-side encryption
• Works everywhere: Lives besides your tabs, follows your browsing

🧠 Model Support

Connect to any of these:

• Cloud APIs: OpenRouter (600+ models, including vision models and Nano Banana Pro), Anthropic Claude, OpenAI GPT, Google Gemini
• Local models: Ollama and LM Studio with automatic CORS configuration
• Smart defaults: Tacit detects vision-capable models automatically

👀 What You Can Feed It

Feed it whatever you're working with:

• "Read This Page": One-click to capture the current tab's text content
• Drag-and-drop files:
  • Images → Vision analysis (screenshots, diagrams, memes)
  • PDFs → Full text extraction
  • Code/Markdown → Syntax-aware parsing

🌐 Web Search

Need answers about what happened yesterday? Enable web search.

• Live Web Access: Enable search to let the AI browse the internet for real-time info.
• Stay Current: Get answers about recent events beyond the model's training data.

⚖️ How We Compare

	Tacit	Typical AI Extensions
Your data	Stays on your device	Sent to their servers
Cost	No subscription. Pay for what you use or nothing (Ollama/LMStudio).	$10–$30/month (marked up subscription)
UI pollution	Clean, minimalistic sidebar	Random UI elements
Model choice	Local models, 600+ cloud	Limited model choice

🚀 Getting Started

📦 Install from Chrome Web Store

Chrome Web Store | Manual Installation

💻 Developer Installation

If you prefer to build from source or contribute:

Prerequisites

• Node.js (v18+)
• npm or pnpm

Steps

1. Clone the repository

   git clone https://github.com/flecomet/tacit-sidebar.git
   cd tacit-sidebar

2. Install dependencies

   npm install

3. Build for production

   npm run build

4. Load into Chrome/Brave/Edge

   • Navigate to chrome://extensions
   • Toggle Developer mode (top right)
   • Click Load unpacked
   • Select the dist folder generated in the previous step.

🛠️ Configuration

Tacit works out of the box once you add an API key:

1. Open the extension (Alt+J).
2. Go to Settings.
3. For Cloud Models: Enter your OpenRouter Key or a custom OpenAI-compatible endpoint URL.
4. For Local Models: Ensure your local server is running (usually http://localhost:11434 for Ollama or http://localhost:1234 for LMStudio).

🏗️ Technical Architecture

Tacit is a "zero-server" application running entirely in the browser:

• Frontend: React + Vite
• Styling: TailwindCSS in Shadow DOM (no CSS leakage to host pages)
• State: Zustand with local persistence
• Security:
  • PBKDF2 + AES-GCM for API key encryption
  • Strict CSP (Content Security Policy)
  • No eval(), no remote code execution

💰 Monetization

Tacit is free and open-source (AGPL-3.0). We're not adding subscriptions, ads, or selling data.

🤝 Contributing

Got an idea? Open an issue first so we can discuss it before you spend time coding.

📄 License

AGPL-3.0 © François Lecomte-Denis