Google Chrome Built-in AI Challenge 2025 — ContentChat AI

ContentChat AI is a privacy-first reading assistant: intelligent summarization, page-aware chat, and an AI writer with proofreader/rewriter — all running locally through Chrome Built-in AI, with a summary library, context menus, and side panel UI. What I built for the challenge — Extension surface: Manifest V3 — background service worker, content scripts, and side panel (React 19, TypeScript, Tailwind CSS v4, Vite, Zustand). — On-device AI: five Chrome Built-in AI APIs behind a small chrome-ai wrapper — Summarizer (streaming), Prompt API / LanguageModel (chat), Writer, Rewriter, Proofreader. — Data & UX: IndexedDB for persisted summaries, context-menu flows, dark/light UI. Architecture Layers match ARCHITECTURE.md: Chrome extension (MV3) → React side panel UI → Zustand stores → services per AI surface → IndexedDB — plus a unified adapter to the built-in APIs. The repo ships full diagrams and flows in docs/ARCHITECTURE.md (same story as the portfolio ARCHITECTURE.md deep dive). For judges & visitors Use the Devpost submission page for screenshots and story, GitHub for source, and the demo video + setup tutorial to enable Chrome AI flags and load the unpacked build from dist.