From 867b8d2408a8f3062f25bd6707a4b96755d70e1d Mon Sep 17 00:00:00 2001
From: Luke Mino-Altherr <luke@comfy.org>
Date: Sun, 3 May 2026 05:44:20 -0700
Subject: [PATCH] fix: gracefully handle port-in-use error on server startup
 (#13001)

Catch EADDRINUSE OSError when binding the TCP site and exit with a clear error message instead of an unhandled traceback.
---
 server.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/server.py b/server.py
index 881da8e66..2f3b438bb 100644
--- a/server.py
+++ b/server.py
@@ -1,3 +1,4 @@
+import errno
 import os
 import sys
 import asyncio
@@ -1245,7 +1246,13 @@ class PromptServer():
             address = addr[0]
             port = addr[1]
             site = web.TCPSite(runner, address, port, ssl_context=ssl_ctx)
-            await site.start()
+            try:
+                await site.start()
+            except OSError as e:
+                if e.errno == errno.EADDRINUSE:
+                    logging.error(f"Port {port} is already in use on address {address}. Please close the other application or use a different port with --port.")
+                    raise SystemExit(1)
+                raise
 
             if not hasattr(self, 'address'):
                 self.address = address #TODO: remove this