From 2188cdc9907cf0934f074a9503501edd68f708e8 Mon Sep 17 00:00:00 2001
From: "Kai (Tam Nhu) Tran" <61256810+kaitranntt@users.noreply.github.com>
Date: Sat, 23 May 2026 21:44:37 -0400
Subject: [PATCH] fix(cliproxy): clean up upstream proxy on response disconnect
 (#1361)

* fix(cliproxy): clean up upstream proxy on response disconnect

* style: apply prettier formatting
---
 src/web-server/routes/cliproxy-local-proxy.ts | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/web-server/routes/cliproxy-local-proxy.ts b/src/web-server/routes/cliproxy-local-proxy.ts
index 9c512e96..4454a297 100644
--- a/src/web-server/routes/cliproxy-local-proxy.ts
+++ b/src/web-server/routes/cliproxy-local-proxy.ts
@@ -134,13 +134,21 @@ export function createCliproxyLocalProxyRouter(deps: CliproxyLocalProxyDeps = {}
       }
     });
 
-    // Clean up proxy connection only when the client aborts the request.
-    // Avoid res.on('close') here because Bun may emit it during local error
-    // responses before the JSON body is flushed, which can truncate 502 payloads.
-    req.on('aborted', () => {
-      if (!res.writableEnded) {
+    const cleanupProxyRequest = () => {
+      if (!proxyReq.destroyed) {
         proxyReq.destroy();
       }
+    };
+
+    // Request-abort cleanup covers disconnects before the response starts.
+    req.on('aborted', cleanupProxyRequest);
+
+    // Response close cleanup covers disconnects while streaming the proxied response.
+    // Guard on writableEnded/finished so successful proxy completions are untouched.
+    res.on('close', () => {
+      if (!res.writableEnded || !res.finished) {
+        cleanupProxyRequest();
+      }
     });
 
     if (bodyBuffer) {