Cognito

The Problem

E-books and digital documents digitize text but don't enhance understanding. When you encounter a complex concept or character you've forgotten, you have to leave the book to Google it, breaking immersion.

The Solution

Cognito isn't just an ebook reader; it's an AI-powered reading companion designed to turn passive reading into active understanding. By integrating state-of-the-art Large Language Models directly into the reading experience, Cognito allows you to converse with your EPUBs and PDFs, extract key insights instantly, and retain more information.

Key Features

Contextual Chat: Ask questions like "What are the key arguments in Chapter 3?" or "Explain this concept like I'm 5," and get answers grounded strictly in the book's text.

Semantic Search: Find concepts, not just keywords. Cognito's vector-based RAG engine understands the context of your library, helping you locate ideas across all your documents.

Hybrid AI Intelligence: Uses Apple Intelligence for private, on-device processing, falling back to powerful cloud models (via OpenRouter) only when deeper analysis is needed.

Privacy-First Design: Your library lives on your device. We don't store your books on our servers. You own your data and your API keys.

Liquid Glass Aesthetic: A modern design language utilizing .ultraThinMaterial, soft gradients, and fluid spring animations that feel native to the latest iOS ecosystem.

Technical Architecture

Built using a modern, forward-looking stack designed for iOS 18 and beyond. The core stack includes Swift 6 with native concurrency, SwiftUI, and SwiftData for persistent storage.

The heart of Cognito is its custom RAG (Retrieval-Augmented Generation) engine, which enables the AI to "read" your book. It features custom text extraction from EPUB (via Readium) and PDF (via PDFKit) files, intelligent text chunking, and a local on-device vector store powered by SQLite.

The AI integration layer uses the FoundationModels framework (Apple Intelligence) for zero-latency, private summarization and chat, with a cloud fallback to OpenRouter for access to top-tier models like GPT-4o and Claude 3.5 Sonnet.