A PDF reader that
talks back.
Built for dense mathematics papers. Highlight
equations to ask your AI assistant questions.
A reading environment for deep work.
Designed for papers, problem sets, and textbooks.
Highlight & Chat
Ask questions directly in context
Highlight any text, equation, or drag a region to capture a diagram. Cauchy opens a thread directly tied to that spot, so your AI assistant knows exactly what you're looking at.
Reference Previews
Never lose your place again
When an author references "Theorem 2.1" pages later, just hover over it. Cauchy generates an on-device index of all definitions, theorems, and equations, showing you a preview instantly.
Native LaTeX rendering
All assistant responses render mathematics natively using SwiftMath, meaning complex equations look perfect and scale beautifully without webviews.
On-device OCR for equations
Drag a box over an equation and Cauchy uses Apple's Vision framework to extract the text, helping the AI understand non-selectable math formulas.
Bring your own intelligence.
Claude Code & Codex
Cauchy automatically detects and uses your local CLI authentications. The app runs unsandboxed to seamlessly integrate with your terminal tools.
Apple Intelligence
Run models entirely on-device on macOS 27.0+. Your documents and queries never leave your Apple Silicon Mac.
Gemini API
Just drop in your Gemini API key in the settings to power your document queries directly through Google's models.
Frequently Asked Questions
What is Cauchy?
A native macOS app to open PDF documents, highlight text, and talk to an AI assistant about it. Perfect for dense technical textbooks and papers.
Where is my data stored?
100% locally on your machine in ~/Library/Application Support/Cauchy/.
Does it upload my PDFs?
No. Cauchy never uploads your documents. If you use a cloud provider like Gemini or Claude, only your query and relevant snippets are sent.
Why unsandboxed?
To utilize your locally installed terminal CLIs (like Claude Code), Cauchy needs to run outside the macOS App Sandbox.