From 3afb8b80c53f0a925aa496262ce7d98229721911 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Tue, 20 Jan 2026 05:19:22 +0000
Subject: [PATCH] feat(socket): add configurable maxListeners to prevent memory
 leaks

Based on RSocket's battle-tested configuration:

- Add maxWebSocketListeners config option (default: 20)
  - 8 base WS events + 10 dynamic listeners + 2 buffer slots
- Add maxSocketClientListeners config option (default: 50)
- Replace dangerous setMaxListeners(0) with configurable limits
- Add warning log if user explicitly sets limit to 0

BREAKING: Previous behavior used setMaxListeners(0) which removed
all limits. Now defaults to safe limits but can be overridden via config.
---
 src/Defaults/index.ts          |  6 +++++-
 src/Socket/Client/types.ts     |  8 +++++++-
 src/Socket/Client/websocket.ts |  8 +++++++-
 src/Types/Socket.ts            | 15 +++++++++++++++
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/src/Defaults/index.ts b/src/Defaults/index.ts
index ea0c3c5d..006f9bb4 100644
--- a/src/Defaults/index.ts
+++ b/src/Defaults/index.ts
@@ -80,7 +80,11 @@ export const DEFAULT_CONNECTION_CONFIG: SocketConfig = {
 	cachedGroupMetadata: async () => undefined,
 	makeSignalRepository: makeLibSignalRepository,
 	// Circuit breaker configuration
-	enableCircuitBreaker: true
+	enableCircuitBreaker: true,
+	// Listener limits (memory leak prevention)
+	// 8 base WS events + 10 dynamic listeners + 2 buffer slots
+	maxWebSocketListeners: 20,
+	maxSocketClientListeners: 50
 }
 
 export const MEDIA_PATH_MAP: { [T in MediaType]?: string } = {
diff --git a/src/Socket/Client/types.ts b/src/Socket/Client/types.ts
index 3a6ee818..cc7c7024 100644
--- a/src/Socket/Client/types.ts
+++ b/src/Socket/Client/types.ts
@@ -13,7 +13,13 @@ export abstract class AbstractSocketClient extends EventEmitter {
 		public config: SocketConfig
 	) {
 		super()
-		this.setMaxListeners(0)
+		// Set max listeners from config (default: 50)
+		// WARNING: 0 disables limit and allows potential memory leaks
+		const maxListeners = this.config.maxSocketClientListeners ?? 50
+		if (maxListeners === 0) {
+			this.config.logger?.warn('SocketClient setMaxListeners(0) allows UNLIMITED listeners - potential memory leak!')
+		}
+		this.setMaxListeners(maxListeners)
 	}
 
 	abstract connect(): void
diff --git a/src/Socket/Client/websocket.ts b/src/Socket/Client/websocket.ts
index 6aab1e3c..59632cd2 100644
--- a/src/Socket/Client/websocket.ts
+++ b/src/Socket/Client/websocket.ts
@@ -31,7 +31,13 @@ export class WebSocketClient extends AbstractSocketClient {
 			agent: this.config.agent
 		})
 
-		this.socket.setMaxListeners(0)
+		// Set max listeners from config (default: 20)
+		// WARNING: 0 disables limit and allows potential memory leaks
+		const maxListeners = this.config.maxWebSocketListeners ?? 20
+		if (maxListeners === 0) {
+			this.config.logger?.warn('WebSocket setMaxListeners(0) allows UNLIMITED listeners - potential memory leak!')
+		}
+		this.socket.setMaxListeners(maxListeners)
 
 		const events = ['close', 'error', 'upgrade', 'message', 'open', 'ping', 'pong', 'unexpected-response']
 
diff --git a/src/Types/Socket.ts b/src/Types/Socket.ts
index 62ab06b5..5d98c075 100644
--- a/src/Types/Socket.ts
+++ b/src/Types/Socket.ts
@@ -165,4 +165,19 @@ export type SocketConfig = {
 
 	/** Circuit breaker configuration for message operations */
 	messageCircuitBreaker?: Partial<CircuitBreakerOptions>
+
+	// === Listener Limits (Memory Leak Prevention) ===
+
+	/**
+	 * Max WebSocket event listeners (default: 20)
+	 * Calculated as: 8 base WS events + 10 dynamic listeners + 2 buffer slots
+	 * WARNING: Setting to 0 disables limit and allows potential memory leaks!
+	 */
+	maxWebSocketListeners?: number
+
+	/**
+	 * Max SocketClient event listeners (default: 50)
+	 * WARNING: Setting to 0 disables limit and allows potential memory leaks!
+	 */
+	maxSocketClientListeners?: number
 }