Solana KitSolana Kit Docs
openbudgetfun/solana_kit ★9999⑂99

Build a Realtime Observer

Turn Solana websocket notifications into a reusable observer layer for your app or service.

Realtime apps often need a thin layer between raw websocket subscriptions and the rest of the application.

That observer layer should own:

  • websocket connection setup
  • subscription registration
  • cancellation
  • stream fanout
  • reconnect/replay policy

Step 1: create a subscription client# 

import 'package:solana_kit_rpc_subscriptions/solana_kit_rpc_subscriptions.dart';

final subscriptions = createSolanaRpcSubscriptions(
  'wss://api.devnet.solana.com',
);

Step 2: register a typed subscription request# 

import 'package:solana_kit_rpc_subscriptions/solana_kit_rpc_subscriptions.dart';
import 'package:solana_kit_rpc_subscriptions_channel_websocket/solana_kit_rpc_subscriptions_channel_websocket.dart';

final controller = AbortController();
final pending = subscriptions.request('slotNotifications');

final stream = await pending.subscribe(
  RpcSubscribeOptions(abortSignal: controller.signal),
);

Step 3: adapt that stream to your own observer interface# 

class SlotObserver {
  SlotObserver(this._subscriptions);

  final RpcSubscriptions _subscriptions;

  Stream<Object?> watchSlots() async* {
    final controller = AbortController();
    final pending = _subscriptions.request('slotNotifications');
    final stream = await pending.subscribe(
      RpcSubscribeOptions(abortSignal: controller.signal),
    );

    yield* stream;
  }
}

In a production app, you would usually hold onto the abort controller so your service can cancel the subscription on shutdown or when the last listener disconnects.

Step 4: subscribe to account or logs updates#

The same pattern works for account or logs subscriptions; only the notification name and params differ. 

final pending = subscriptions.request('accountNotifications', [
  '11111111111111111111111111111111',
  {'encoding': 'base64', 'commitment': 'confirmed'},
]);

Step 5: make reconnect policy explicit#

Transport disruptions are normal. Decide up front how your observer should behave when the socket drops:

  • reconnect immediately or with backoff?
  • replay active subscriptions automatically?
  • publish a disconnected state to downstream consumers?
  • buffer, debounce, or drop noisy updates?

Keeping this logic in one observer layer prevents UI code from learning socket lifecycle rules.