Architecture: Share with Everyone

Decision

Alternative	Pros	Cons	Decision
Activate existing is_public field (chosen)	Zero schema migration, leverages existing field	Full read+write access (no read-only yet)	Selected
New sharing tier with separate collection	Clean separation, granular permissions	Migration needed, more complex queries	Rejected
Link-based public sharing (share URL)	No auth required for viewing	Security risk, no audit trail	Rejected
Organization-wide team group	Uses existing team infrastructure	Requires all users in a team, admin overhead	Rejected

Solution Architecture

Access Control Flow

The requireConversationAccess middleware in api-middleware.ts checks access in priority order:

Request ──▶ requireConversationAccess(conversationId, session)
  │
  ├── 1. Owner? ──▶ GRANT (full access)
  ├── 2. sharing.is_public === true? ──▶ GRANT (any authenticated user)
  ├── 3. shared_with includes user? ──▶ GRANT
  ├── 4. shared_with_teams includes user's team? ──▶ GRANT
  ├── 5. sharing_access record exists? ──▶ GRANT
  └── None matched ──▶ DENY (403)

The is_public check at position 2 short-circuits the more expensive team membership lookups when a conversation is public.

API Changes

The share endpoint accepts is_public as a standalone toggle -- no user_emails or team_ids required:

POST /api/chat/conversations/[id]/share
Body: { "is_public": true }   ← standalone toggle
Body: { "is_public": true, "user_emails": [...] }  ← combined

MongoDB update: $set: { "sharing.is_public": true/false }

Query Changes

Both conversation listing and shared listing add is_public to their $or conditions:

{ $or: [
    { owner_id: userId },
    { 'sharing.shared_with': userEmail },
    { 'sharing.shared_with_teams': { $in: userTeams } },
    { 'sharing.is_public': true }    // ← new condition
] }

Data Model

No schema changes -- is_public already existed on Conversation.sharing with default false:

sharing: {
  is_public: boolean;            // activated by this feature
  shared_with: string[];
  shared_with_teams: string[];
  share_link_enabled: boolean;
  share_link_expires?: Date;
}

UI Indicators

State	Sidebar Icon	Color
Public (is_public: true)	Globe	Green
Shared (users/teams only)	Users	Blue
Private (not shared)	None	Default

The ShareDialog includes a toggle switch with Globe icon and shows "Everyone" in the access list when public.

Components Changed

File	Description
ui/src/lib/api-middleware.ts	Added is_public check at position 2 in requireConversationAccess
ui/src/app/api/chat/conversations/[id]/share/route.ts	Handles is_public toggle as standalone action; validates owner-only
ui/src/app/api/chat/conversations/route.ts	Added { 'sharing.is_public': true } to listing $or conditions
ui/src/app/api/chat/shared/route.ts	Added { 'sharing.is_public': true } to shared listing $or conditions
ui/src/components/chat/ShareDialog.tsx	Toggle switch UI, "Everyone" access list entry, handleTogglePublic handler
ui/src/components/layout/Sidebar.tsx	Globe icon (green) for public conversations vs Users icon (blue)
ui/src/types/mongodb.ts	Added is_public?: boolean to ShareConversationRequest

Related

• Spec: spec.md