A privacy-first, open-source Chrome extension that captures context from one AI chat and bridges it to another — instantly.
Capsule Hub solves a very real daily pain point: switching between AI models mid-conversation without losing context.
Imagine you're deep in a coding session with Claude, and you run out of free-tier messages. You need to switch to ChatGPT — but you don't want to re-explain your entire project, goals, and progress. Capsule Hub captures the full context — what you asked, what the AI planned, where you are now — and seamlessly injects it into your next AI tool.
- 📝 Progress — What the AI has accomplished so far
- 🎯 Goals — Your original objectives and requirements
- 📊 Plan — The AI's proposed approach and next steps
- 💻 Code blocks — All code snippets preserved with formatting
- 💬 Full conversation — Every user prompt and AI response
Many existing "context bridge" extensions on the Chrome Web Store send your entire AI conversations to their own servers, including extensions that request access to your Gmail, Outlook, downloads, and identity. Your AI conversations often contain proprietary code, business ideas, and personal data.
Capsule Hub was built as a privacy-first alternative:
| Privacy Feature | Capsule Hub (Ours) | Typical Alternatives |
|---|---|---|
| Data stays in browser | ✅ Yes, 100% local | ❌ Sends data to external servers |
| Open source | ✅ Fully auditable code | ❌ Closed source |
| Email access | ❌ None | |
| Download tracking | ❌ None | downloads permission |
| Identity/OAuth access | ❌ None | identity permission |
| External servers | ❌ Zero network calls | ❌ Communicates with external backend |
| WebAssembly execution | ❌ Not allowed | wasm-unsafe-eval |
| Free to use | ✅ Always free | ❌ Paid tiers |
Your AI conversations contain sensitive work data. Our extension processes everything locally in your browser. No data is ever sent to any server. Verify it yourself — the code is open source.
Capsule Hub uses three context extraction modes to wrap your AI conversation:
Captures the entire conversation verbatim — every user prompt and AI response, cleaned of UI elements (buttons, icons, feedback widgets). The text is wrapped with a structured header that tells the target AI:
- Where this conversation came from
- That it should continue seamlessly
- To respond to the last user prompt
Lets you hand-pick which messages to include. Perfect for removing irrelevant tangents or failed approaches while keeping the important context.
An intelligent extraction that identifies and structures:
- 📌 Initial Goal — What you originally asked the AI to do
- 🎯 Key Decisions — Important choices made during the conversation
- 💬 Critical Exchanges — The most important user↔AI interactions (first 3 + last 2)
- 🏁 Current State — Where things stand right now
- 💻 Code Blocks — Any code snippets preserved exactly as written
This is processed entirely in your browser using pattern recognition on the conversation structure — no AI summarizer API is called. The algorithm looks for:
- First message = your initial goal/request
- User→Assistant pairs = key exchanges
- Code fence patterns (```) = important code blocks
- Last messages = current state and pending tasks
- Auto-Context Extraction — Automatically detects and extracts the full conversation from supported AI providers
- Smart Scrolling — Scrolls to the top of the chat to capture ALL messages, even in long conversations
- Intelligent Wrapping — Structured context with goal/progress/plan extraction
- Code Block Preservation — Code snippets are kept intact with language identifiers
- Turn-Based Selection — Interactively select which parts of the conversation to transfer
- Three Context Modes — Full Context, Selective, or Smart Summary
- Capsule History — Save capsules locally and reuse them later
- Seamless Injection — Opens the destination AI, waits for the input to load, and injects context automatically
- React/Vue Compatible — Uses modern InputEvent API for framework-compatible text injection
- Export as Markdown — Download capsules as .md files for external use
- Manual Entry — Paste custom context from any source
- Clipboard Fallback — Copy formatted context to clipboard if auto-injection fails
- Token Estimation — See approximate token count before transferring
- Privacy Badge — Always-visible indicator that your data stays local
capsule-hub-extension/
├── manifest.json # Extension configuration (Manifest V3)
├── background.js # Service worker for tab management and badges
├── content.js # DOM extraction and text injection logic
├── content.css # Toast notification and injection indicator styles
├── popup.html # Extension popup UI structure
├── popup.js # Popup controller and state management
├── popup.css # Dark theme styling (no external fonts)
├── icon.svg # Source vector icon
├── icon16.png # 16x16 toolbar icon
├── icon48.png # 48x48 extension management icon
├── icon128.png # 128x128 Chrome Web Store icon
├── LICENSE # MIT License
└── README.md # This file
-
Clone the repository:
git clone https://github.com/pruthvikrishnang/capsule-hub-extension.git cd capsule-hub-extension -
Load in Chrome/Brave:
- Navigate to
chrome://extensions(orbrave://extensions) - Enable Developer Mode (toggle in top-right)
- Click Load unpacked
- Select the cloned
capsule-hub-extensionfolder
- Navigate to
-
Pin for easy access:
- Click the puzzle piece icon in your toolbar
- Pin Capsule Hub - AI Context Bridge
| Provider | URL | Status |
|---|---|---|
| 🤖 ChatGPT | chatgpt.com |
✅ Supported |
| 🎨 Claude | claude.ai |
✅ Supported |
| ✨ Gemini | gemini.google.com |
✅ Supported |
| 🐳 DeepSeek | chat.deepseek.com |
✅ Supported |
- Start a conversation in any supported AI tool (e.g., Claude)
- Click the Capsule Hub icon in your browser toolbar
- Review the captured messages — all your turns are automatically detected
- Choose your mode:
- Full Context — Transfer the entire conversation with structured header
- Selective — Pick specific messages to include
- Smart Summary — Auto-extracted goals, progress, and key decisions
- Click a destination (e.g., ChatGPT) — a new tab opens with your context injected
- Review and hit Enter — the new AI now has your full context!
- Click "Save Capsule" to store the current context locally
- Access saved capsules from the Capsule Library tab
- Reuse, export, or bridge saved capsules to any AI tool
Capsule Hub collects ZERO data.
- ✅ All context extraction happens locally in your browser
- ✅ Conversation data is stored only in
chrome.storage.local(your browser profile) - ✅ No analytics, no telemetry, no external API calls
- ✅ No external font loading, no CDN requests
- ✅ No user accounts, no login required
- ✅ Source code is fully auditable — verify it yourself
- ✅ Pending context auto-clears after 2 minutes
- ✅ No data persists after you click "Clear Context"
Technical verification: The extension makes zero fetch(), XMLHttpRequest, or WebSocket calls. You can verify this by opening DevTools Network tab while using the extension — you'll see no outgoing requests.
We believe your AI conversations are private. Period.
Contributions are welcome! This is an open-source project and we'd love your help making it better.
- Fork the repository
- Create a feature branch:
git checkout -b feature/my-feature - Commit your changes:
git commit -am 'Add some feature' - Push to the branch:
git push origin feature/my-feature - Submit a pull request
This project is licensed under the MIT License — see the LICENSE file for details.
Built with ❤️ by Pruthvi Krishna N G
If this extension helps your workflow, please ⭐ star the repo and share it!