Every day, millions of people open dozens of browser tabs—research articles, product pages, social media, work documents—and never close them. Why? Because closing a tab feels like losing it forever.
Calvin solves this with AI. Here's exactly how it works under the hood.
The Architecture Overview
Calvin's intelligence comes from three core systems working together:
Let's dive into each.
Content Extraction: Beyond the URL
A URL tells you almost nothing. medium.com/p/abc123 could be about quantum physics or sourdough bread. Calvin needs to understand the content.
When you save a tab, Calvin extracts:
This extraction happens locally in your browser for privacy. Only the processed, anonymized features get sent to our servers.
Semantic Embeddings: The Math of Meaning
Here's where it gets interesting. Calvin converts each tab's content into a 768-dimensional vector—a point in high-dimensional space where similar content clusters together.
We use a fine-tuned sentence transformer model optimized for:
The embedding model runs on our infrastructure, but we never store your raw content—only the vectors and metadata needed for organization.
Intelligent Clustering: Finding Natural Groups
With thousands of tabs represented as vectors, Calvin uses a modified HDBSCAN algorithm to find natural groupings. Why HDBSCAN?
The clustering considers:
The Learning Loop
Calvin gets smarter the more you use it. When you:
This feedback fine-tunes your personal organization model without ever sharing your data with other users.
Privacy by Design
Everything described above was built with privacy as a core constraint:
What's Next
We're working on:
Tab management is just the beginning. The same architecture will power our future products for organizing your entire digital life.
Want to try it yourself? Get Calvin and experience intelligent tab management.