Zero Data Collection by Developer

Privacy Policy

App: Eureka Buddy for iOS & iPadOS
Last updated: October 14, 2026

Short Summary Eureka Buddy runs locally on your device. We do not operate any backend server, require any user account, or include any analytics, crash-reporting, advertising, or tracking SDKs. Your PDFs, notes, knowledge graphs, and chat history stay on your device unless you explicitly enable and consent to an optional third-party Cloud AI provider.

1. Developer & Contact Information

Eureka Buddy is developed and published by Roberto Sánchez, an individual developer residing in Mexico.

If you have any questions about this Privacy Policy or how the app handles data, please contact: support@tebasia.mx.

2. What the App Does

Eureka Buddy reads PDFs and answers questions about them with AI. It also writes margin notes, builds a knowledge graph of the book, takes excerpts and drawings, and keeps a chat history.

3. No Account & No Developer Server

The developer runs no backend server. There is no sign-in, no analytics or crash-reporting SDK, no advertising, no tracking, and no iCloud sync. The app's Apple Privacy Manifest (PrivacyInfo.xcprivacy) declares no data collected and no tracking. This website also uses no cookies, analytics, or third-party tracking scripts.

4. Data Stored Only on Your Device

All of the following data is stored exclusively on your device inside the app's own container and is permanently deleted when you delete the app:

Imported PDFs, annotations, AI margin notes, excerpts, drawings, chat archives, book indexes and knowledge graphs, reading position, and app settings.
API keys you enter for Google Gemini, Anthropic, or LM Studio. These keys are stored securely in the iOS Keychain on your device and are only sent directly to the respective provider or server you configure.
Downloaded on-device AI models.

5. On-Device AI (Nothing Leaves Your Device)

When you use on-device AI features, all processing happens locally on your iPhone or iPad and no document content leaves your device:

Apple Intelligence: Uses Apple's on-device Foundation Models framework.
Local MLX Models: Runs locally on your device. When you choose to download a local model, the model files are downloaded directly from Hugging Face (huggingface.co). That request only fetches model files and includes no document content. Hugging Face sees a standard file download request (such as your device's IP address).
On-Device OCR: Scanned PDFs are processed locally on your device using Apple Vision.

6. Optional Cloud AI (Only If You Turn It On and Consent)

Eureka Buddy optionally lets you connect to third-party cloud AI providers using your own API key:

Supported Providers: Google Gemini (generativelanguage.googleapis.com) and Anthropic Claude (api.anthropic.com).
Explicit Consent Required: The app displays a clear consent screen before any cloud request is made and will not send anything without your consent. You can withdraw your consent at any time in Settings › About & Privacy.
What Is Sent When Enabled: Your questions and chat history, text from the PDF pages you ask about, images of pages or selections you attach, and your own API key.
Third-Party Policies: Google and Anthropic are independent third parties and may collect, retain, and use the data sent to them under their own privacy policies:
- Google Privacy Policy: https://policies.google.com/privacy
- Anthropic Privacy Policy: https://www.anthropic.com/legal/privacy
No Developer Access: Requests go directly from your device to Google or Anthropic. The developer never receives a copy of your prompts, documents, or API keys.

7. Your Own Local Server (Optional LM Studio)

You may optionally connect Eureka Buddy to an LM Studio server running on your own computer over your local Wi-Fi network or Tailscale. Requests go only to the server address you enter. Because connecting to a local IP address requires local network access on iOS/iPadOS, the app asks for Local Network permission when you use this feature.

8. Reference Lookups (Research Features)

To display related articles and academic papers when you use research lookup features, the app sends search terms (short phrases, titles, or author names drawn from the document) directly to:

Wikipedia (en.wikipedia.org)
arXiv (export.arxiv.org)
OpenAlex (api.openalex.org)
Crossref (api.crossref.org)

These lookup requests contain no user account information. Those services see the search request and your device's IP address.

9. Math Rendering

To render mathematical notation, the formula view loads the open-source KaTeX library from cdn.jsdelivr.net. No document content is sent in that request.

10. In-App Purchases

None. Eureka Buddy has no in-app purchases or paid features, and the developer collects no payment or billing details.

11. Children's Privacy

Eureka Buddy is not directed at children under the age of 13, and we do not knowingly collect personal information from children.

12. Your Rights & Data Deletion

Because all app data is stored locally on your device, deleting individual documents inside the app or uninstalling Eureka Buddy from your device immediately deletes that data. You can also remove saved API keys or withdraw Cloud AI consent at any time in Settings › About & Privacy.

Any data you chose to send directly to Google Gemini or Anthropic Claude is governed by their respective privacy policies. For any privacy questions, email support@tebasia.mx.

13. Changes to This Policy

This Privacy Policy may be updated from time to time to reflect app updates or legal requirements. Whenever it is updated, the "Last updated" date at the top of this page will be revised.