config.json

@@ -5,6 +5,7 @@
   "enableWebsocket": true,
   "enableTCPSocket": true,
   "enablePolling": true,
+  "wildcardChannel": "*",
   "pollingInterval": 3600,
   "enablePrometheus": true
 }

public/index.html

@@ -186,6 +186,7 @@
         <h3>Opening a channel</h3>
         <div class="sub">
             <p>Opening channels allows the receiving of messages from other clients.</p>
+            <p>The <b>Wildcard</b> to listen to all channels is <code>*</code>.</p>
             <table>
                 <tr>
                     <th>Field</th>

src/common.ts

@@ -41,6 +41,7 @@ export interface Server {
         enableWebsocket: boolean,
         enableTCPSocket: boolean,
         enablePolling: boolean,
+        wildcardChannel: string,
         pollingInterval: number,
         enablePrometheus: boolean,
     },

src/index.ts

@@ -114,6 +114,11 @@ function transmitMessage(sessionId: string, channel: string | number, message: a
         }
     }
 
+    if (channel === config.wildcardChannel) return {
+        ok: false,
+        error: config.wildcardChannel + " is read-only",
+    }
+
     // Build the message meta
     let meta: MetaMessage = (rawMeta || {}) as MetaMessage;
 
@@ -147,6 +152,21 @@ function transmitMessage(sessionId: string, channel: string | number, message: a
         })
     }
 
+    // Send message to wildcard channel
+
+    let wildcardChannelArray = server.channels[config.wildcardChannel];
+    if (wildcardChannelArray) {
+        wildcardChannelArray.forEach(recipientId => {
+            server.clients[recipientId]?.send({
+                type: "message",
+                channel: config.wildcardChannel,
+                message: message,
+                meta: meta,
+            })
+            server.prometheus.messagesTrafficCounter.labels('outgoing').inc();
+        })
+    }
+
     return {
         ok: true,
     };