diff --git a/src/infra/unhandled-rejections.test.ts b/src/infra/unhandled-rejections.test.ts
index b6008fdcfa3..3a04baec26b 100644
--- a/src/infra/unhandled-rejections.test.ts
+++ b/src/infra/unhandled-rejections.test.ts
@@ -400,6 +400,12 @@ describe("isTransientUnhandledRejectionError", () => {
     const wrappedDestroyedHttp2Session = Object.assign(new Error("model call failed"), {
       cause: destroyedHttp2Session,
     });
+    const wsPreHandshakeClose = new Error(
+      "WebSocket was closed before the connection was established",
+    );
+    const wrappedWsPreHandshakeClose = Object.assign(new Error("feishu reconnect failed"), {
+      cause: wsPreHandshakeClose,
+    });
     const generic = new Error("boom");
 
     expect(isBenignUncaughtExceptionError(epipe)).toBe(true);
@@ -414,6 +420,13 @@ describe("isTransientUnhandledRejectionError", () => {
     expect(isBenignUncaughtExceptionError(destroyedHttp2Session)).toBe(true);
     expect(isBenignUncaughtExceptionError(wrappedDestroyedHttp2Session)).toBe(true);
     expect(isBenignUncaughtExceptionError(new Error("ERR_HTTP2_INVALID_SESSION"))).toBe(true);
+    expect(isBenignUncaughtExceptionError(wsPreHandshakeClose)).toBe(true);
+    expect(isBenignUncaughtExceptionError(wrappedWsPreHandshakeClose)).toBe(true);
+    expect(
+      isBenignUncaughtExceptionError(
+        new Error("WebSocket error: WebSocket was closed before the connection was established"),
+      ),
+    ).toBe(false);
     expect(isBenignUncaughtExceptionError(generic)).toBe(false);
   });
   it("returns true for transient SQLite errors", () => {
diff --git a/src/infra/unhandled-rejections.ts b/src/infra/unhandled-rejections.ts
index afce28bbecc..243c5a8be16 100644
--- a/src/infra/unhandled-rejections.ts
+++ b/src/infra/unhandled-rejections.ts
@@ -111,6 +111,7 @@ const TRANSIENT_NETWORK_MESSAGE_CODE_RE =
   /\b(ECONNRESET|ECONNREFUSED|ENOTFOUND|ETIMEDOUT|ESOCKETTIMEDOUT|ECONNABORTED|EPIPE|ENETDOWN|EHOSTUNREACH|ENETUNREACH|EADDRNOTAVAIL|EAI_AGAIN|EPROTO|UND_ERR_CONNECT_TIMEOUT|UND_ERR_DNS_RESOLVE_FAILED|UND_ERR_CONNECT|UND_ERR_SOCKET|UND_ERR_HEADERS_TIMEOUT|UND_ERR_BODY_TIMEOUT|ERR_HTTP2_INVALID_SESSION)\b/i;
 const BENIGN_UNCAUGHT_EXCEPTION_NETWORK_MESSAGE_CODE_RE =
   /\b(ECONNREFUSED|ENETDOWN|EHOSTUNREACH|ENETUNREACH|EADDRNOTAVAIL|EAI_AGAIN|ENOTFOUND|ETIMEDOUT|UND_ERR_CONNECT_TIMEOUT|UND_ERR_DNS_RESOLVE_FAILED|UND_ERR_CONNECT|ERR_HTTP2_INVALID_SESSION)\b/i;
+const WS_PRE_HANDSHAKE_CLOSE_MESSAGE = "websocket was closed before the connection was established";
 
 const TRANSIENT_SQLITE_MESSAGE_CODE_RE =
   /\b(SQLITE_BUSY|SQLITE_CANTOPEN|SQLITE_IOERR|SQLITE_LOCKED)\b/i;
@@ -176,6 +177,16 @@ function isWrappedFetchFailedMessage(message: string): boolean {
   return /:\s*fetch failed$/.test(message);
 }
 
+function isBenignUncaughtNetworkMessage(message: string): boolean {
+  if (BENIGN_UNCAUGHT_EXCEPTION_NETWORK_MESSAGE_CODE_RE.test(message)) {
+    return true;
+  }
+
+  // `ws` emits this exact Error when close()/terminate() aborts a CONNECTING socket.
+  // Keep exact matching so arbitrary WebSocket errors still take the fatal path.
+  return message === WS_PRE_HANDSHAKE_CLOSE_MESSAGE;
+}
+
 function getErrorCause(err: unknown): unknown {
   if (!err || typeof err !== "object") {
     return undefined;
@@ -437,7 +448,7 @@ function isBenignUncaughtNetworkException(err: unknown): boolean {
       continue;
     }
     const message = normalizeLowercaseStringOrEmpty((candidate as { message?: unknown }).message);
-    if (message && BENIGN_UNCAUGHT_EXCEPTION_NETWORK_MESSAGE_CODE_RE.test(message)) {
+    if (message && isBenignUncaughtNetworkMessage(message)) {
       return true;
     }
   }