Realtime Messaging with WebSockets

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Feature description

Integrate a realtime messaging system in the student marketplace using WebSockets.
Messages should sync instantly across clients with delivery/read status, typing indicators, and optional notifications.

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Why is it needed?

• Current delay in communication will lead to poor user experience

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Issue to be solved

Right now, users have to refresh pages or wait for long polling. This will cause:

• Missed opportunities (urgent sales like textbooks, tickets, or roommates).
• Low trust (delayed replies feel like ghosting).
• User churn (they default to external apps).

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Any possible alternatives or similar features you’ve seen elsewhere

• WhatsApp / Messenger → instant delivery with ticks & read receipts.
• Discord / Slack → typing status and presence indicators.
• Facebook Marketplace → chat tied to listings.

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Technical Approach (WebSockets)

Transport Layer

• Use WebSockets for realtime bi-directional communication.

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Server-side Design

• Maintain a WebSocket server that:
  • Handles user connections (one socket per logged-in user).
  • Manages chat rooms (one per conversation/listing).
  • Emits events: message, delivered, read, typing.
• Store messages in a persistent database ie Postgres via supabase
• Use Redis for horizontal scaling → sync messages across multiple servers.

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Client-side Integration

• Connect to WebSocket server on login.
• Join relevant chat rooms when opening conversation.
• Emit events:
  • send_message (with message payload).
  • typing (on key press).
• Listen for:
  • new_message (render instantly).
  • delivered & read updates.

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Extra Features (future-proof)

• Push notifications for offline users (FCM for Android, Web Push for browsers).
• Message attachments (images, docs).
• End-to-end encryption
• Presence indicators (online/offline).