Made with Lumo...

Build a privacy-first PKM app that combines MyMind's frictionless card interface with Proton's zero-knowledge encryption.

THE PROBLEM:
Existing second-brain tools force you to choose between privacy and usability:
- Notion/Evernote: Great UX but no encryption, data harvested for AI
- Obsidian: Privacy-focused but DIY sync, no built-in AI
- MyMind: Beautiful card UI but opaque privacy practices
- Standard Notes: Encrypted but dated interface, no visual organization

THE SOLUTION:
Proton Brain—a card-based knowledge system where everything you save (notes, links, images, PDFs, emails) becomes a single unified card in an infinite grid. No folders required. No manual tagging. Just save and find later.

KEY FEATURES REQUESTED:
1. Card-Based Interface:
- All content rendered as expandable cards in a search-first grid
- No folder hierarchy—everything discoverable via search
- Reader mode for distraction-free article consumption
- Swipe gestures on mobile (archive, pin, share)

1. Universal Capture:

   • Browser extension web clipper
   • Forward emails from Proton Mail → auto-creates card
   • Mobile quick-save from clipboard/screenshot
   • Drag-drop from Drive/Mail into Proton Brain

2. Content Types:

   • Text notes, web clips, images, PDFs, audio/video
   • Unified card design regardless of type
   • Child cards for highlights/annotations
   • Source attribution preserved (click-through to original)

3. Privacy Guarantee:

   • All cards zero-access encrypted (even Proton can't read them)
   • No training on user content
   • Swiss jurisdiction + no-logs policy
   • Optional client-side AI inference (no server processing)
   • Ghost mode for ephemeral cards

4. Pricing Model:

   • Free tier: 100 cards limit
   • Plus/Visionary: Unlimited cards included
   • Leverages existing Drive storage allocation

WHY PROTON?
Proton already has the pieces: Drive (encrypted storage), Docs (editing), Lumo (AI). This unifies them into a single PKM experience that competes with Big Tech tools without compromising privacy.

TECHNICAL REFERENCES:
- UI inspiration: MyMind.com card design
- Sync: Integrate with existing Proton Drive SDK
- Search: Full-text + semantic across encrypted index
- Mobile: Native iOS/Android apps with widgets

"Notion has features. Obsidian has flexibility. Proton has trust. Now combine them."

A privacy-first second brain isn't just a nice-to-have—it's essential infrastructure for anyone who treats their thoughts and knowledge as sensitive data. Proton is uniquely positioned to deliver this because it already trusts users with their email, calendar, VPN, and password data. Extending that trust to personal knowledge would cement Proton as the complete alternative to Big Tech productivity suites.

VOTE IF YOU WANT: A beautiful, private second brain that doesn't sell your data.