canvas-website/backlog/tasks/task-038 - Real-Time-Location-Presence-with-Privacy-Controls.md

id	title	status	assignee	created_date	updated_date	labels	dependencies	priority
task-038	Real-Time Location Presence with Privacy Controls	Done		2025-12-05 02:00	2025-12-05 02:00	feature open-mapping privacy collaboration		high

Description

Implemented real-time location sharing with trust-based privacy controls for collaborative mapping.

Key features:

• Privacy-preserving location via zkGPS commitments
• Trust circle precision controls (intimate ~2.4m → public ~630km)
• Real-time broadcasting and receiving of presence
• Proximity detection without revealing exact location
• React hook for easy canvas integration
• Map visualization components (PresenceLayer, PresenceList)

Files created in src/open-mapping/presence/:

• types.ts: Comprehensive type definitions
• manager.ts: PresenceManager class with location watch, broadcasting, trust circles
• useLocationPresence.ts: React hook for canvas integration
• PresenceLayer.tsx: Map visualization components
• index.ts: Barrel export

Integration pattern:

const presence = useLocationPresence({
  channelId: 'room-id',
  user: { pubKey, privKey, displayName, color },
  broadcastFn: (data) => automergeAdapter.broadcast(data),
});

// Set trust levels for contacts
presence.setTrustLevel(bobKey, 'friends'); // ~2.4km precision
presence.setTrustLevel(aliceKey, 'intimate'); // ~2.4m precision

Acceptance Criteria

• #1 Location presence types defined
• #2 PresenceManager with broadcasting
• #3 Trust-based precision controls
• #4 React hook for canvas integration
• #5 Map visualization components
• #6 Proximity detection without exact location