Most modern browser AI reading assistants operate in the cloud. Every time you ask a question or read a page, your browsing history, active tabs, and queries are shipped off to a proprietary backend database.
I wanted a private, zero-subscription reading companion that ran 100% locally on my machine.
To solve this, I built ContextBridge—a Chrome extension that sits in your sidebar, indexes web pages to Markdown, stores them locally, and lets you chat with them offline using local LLMs via Ollama.
In this article, I’ll walk through the architectural choices of building a local-first extension using Chrome’s Manifest V3, IndexedDB, and Ollama.
The Architecture: Why Local-First in a Browser?
