From d7213c255c8f215bc4a0f5ed3e6aa79c82178cda Mon Sep 17 00:00:00 2001
From: MartinBraquet <martin.braquet@gmail.com>
Date: Thu, 9 Oct 2025 17:50:43 +0200
Subject: [PATCH] Add client side heartbeat

---
 common/src/api/websocket-client.ts | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/common/src/api/websocket-client.ts b/common/src/api/websocket-client.ts
index 74ee83e..28da69d 100644
--- a/common/src/api/websocket-client.ts
+++ b/common/src/api/websocket-client.ts
@@ -54,7 +54,7 @@ export class APIRealtimeClient {
   // subscribers by the topic they are subscribed to
   subscriptions: Map<string, BroadcastHandler[]>
   connectTimeout?: NodeJS.Timeout
-  heartbeat?: NodeJS.Timeout
+  heartbeat?: number | undefined;
 
   constructor(url: string) {
     this.url = url
@@ -90,10 +90,12 @@ export class APIRealtimeClient {
       if (VERBOSE_LOGGING) {
         console.info('API websocket opened.')
       }
-      this.heartbeat = setInterval(
-        async () => this.sendMessage('ping', {}).catch(console.error),
-        30000
-      )
+      // Send a heartbeat ping every 25s
+      this.heartbeat = window.setInterval(() => {
+        if (this.ws.readyState === WebSocket.OPEN) {
+          this.ws.send(JSON.stringify({ type: "ping" }));
+        }
+      }, 25000);
       if (this.subscriptions.size > 0) {
         this.sendMessage('subscribe', {
           topics: Array.from(this.subscriptions.keys()),
@@ -105,7 +107,7 @@ export class APIRealtimeClient {
       if (VERBOSE_LOGGING) {
         console.info(`API websocket closed with code=${ev.code}: ${ev.reason}`)
       }
-      clearInterval(this.heartbeat)
+      if (this.heartbeat) clearInterval(this.heartbeat)
 
       // mqp: we might need to change how the txn stuff works if we ever want to
       // implement "wait until i am subscribed, and then do something" in a component.