Nexus Reader Privacy Policy
Effective October 12, 2026
Nexus Reader ("the app") is a reading and research app for Mac. This policy explains what happens to your information when you use it.
The short version
- Your library — papers, web pages, videos, highlights, notes — stays on your Mac.
- We (the developer) don't run any server that receives your data, and the app has no analytics, advertising, tracking, or crash reporting.
- When you use an AI feature, voice input, or import something from the web, the app talks directly to the service involved, on your behalf. Before anything goes to an AI or voice service for the first time, the app asks you.
What stays on your Mac
Everything you add to Nexus Reader is stored in the app's own folder on your Mac (its App Sandbox container): your library database, downloaded PDFs and saved pages, highlights, notes, and settings. API keys you enter are kept in the macOS Keychain. If you choose a sync folder (for example in iCloud Drive or Dropbox), the app writes copies of your library there; whatever service syncs that folder handles it under its own terms. The app itself never uploads your library anywhere.
What leaves your Mac, and only when you use it
AI features. When you ask a question, explain a passage, chat about a paper, or preview a citation or link, the app sends what's needed for the answer — your question, the text or image you selected, the document's text, and the conversation so far — to the AI service you chose:
- Anthropic (Claude), either through your own Claude account (signed in inside the app) or your own Anthropic API key;
- or another service you set up with your own key (for example OpenAI, Google Gemini, DeepSeek, Alibaba Qwen, Moonshot Kimi, Zhipu GLM, or OpenRouter);
- or a model running on your own Mac (Ollama or LM Studio), in which case nothing leaves your Mac.
The app asks for your permission before sending anything to an AI service for the first time, and you can withdraw it in Settings › Sharing with AI services. Some features run automatically once you've allowed them, such as preparing a page's layout, adding punctuation to automatic video captions, or summarizing a link or citation you hover over. Each service handles your data under its own privacy policy and your agreement with it. Anthropic's claude.ai sign-in happens on Anthropic's own website.
Voice input. When you press the microphone, your speech is streamed to the voice service you chose (Deepgram or Alibaba Cloud), together with a few nearby words from your document to help it recognize terms. The app asks before the first time. Audio isn't stored by the app.
Adding and reading sources. When you add or open a paper, web page, post, or video, the app fetches it from where it lives: the website itself; arXiv, Crossref, and Semantic Scholar for paper details and references (sent: the paper's identifier or title); YouTube, Vimeo, or Bilibili for videos and captions (sent: the video's identifier); FxTwitter for X posts (sent: the post's identifier). Pages you browse in the app's built-in browser are loaded like in any browser, and sites may keep cookies there, as they would in Safari.
Page layout model. If you agree, the app downloads a layout model once from Hugging Face. Nothing about you is sent beyond an ordinary download request.
What we don't do
We don't collect, sell, or share your personal information. We don't track you across apps or websites. We have no access to your library, your questions, or your accounts with other services.
Children
Nexus Reader isn't directed at children under 13, and we don't knowingly collect information from anyone.
Your choices
You can delete anything from your library at any time, withdraw AI or voice permissions in Settings, sign out of Claude in Settings, and remove the app to delete everything it stored on your Mac (copies in a sync folder you chose stay there until you delete them).
Changes
If this policy changes, the new version will be posted here with a new effective date.
Contact
Questions about privacy: [email protected]