Supabase Realtime streams PostgreSQL changes to clients over WebSocket. Combine it with Flutter and you can ship live notifications, "who's online" indicators, and collaborative editing in dozens of lines of code. This guide covers all three channel types — Postgres Changes, Presence, and Broadcast — with production-ready examples.

The Three Channel Types

Type Use Case Data Source

Postgres Changes React to INSERT/UPDATE/DELETE PostgreSQL WAL

Broadcast Client-to-client events Realtime server

Presence "Who's online" state sync Realtime server

Setup

# pubspec.yaml dependencies : supabase_flutter : ^2.5.0

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// main.dart import 'package:supabase_flutter/supabase_flutter.dart' ;

void main () async { await Supabase . initialize ( url: 'https://<project>.supabase.co' , anonKey: '<anon-key>' , realtimeClientOptions: const RealtimeClientOptions ( eventsPerSecond: 10 , logLevel: RealtimeLogLevel . info , ), ); runApp ( const App ()); }

final supabase = Supabase .…