diff --git a/src/app/v1/_lib/proxy/client-abort-listener.ts b/src/app/v1/_lib/proxy/client-abort-listener.ts
index d47758907..7ebd24153 100644
--- a/src/app/v1/_lib/proxy/client-abort-listener.ts
+++ b/src/app/v1/_lib/proxy/client-abort-listener.ts
@@ -1,3 +1,9 @@
+/**
+ * 绑定客户端中止监听器，返回幂等清理函数。
+ *
+ * 注意：如果传入的 signal 已经 aborted，会在当前调用栈同步执行 onAbort。
+ * 调用方必须先初始化 onAbort 闭包会访问的控制器、任务 ID 等资源。
+ */
 export function bindClientAbortListener(
   signal: AbortSignal | null | undefined,
   onAbort: () => void
diff --git a/tests/unit/proxy/response-handler-abort-listener-cleanup.test.ts b/tests/unit/proxy/response-handler-abort-listener-cleanup.test.ts
index c5dda43b9..af0dd96f7 100644
--- a/tests/unit/proxy/response-handler-abort-listener-cleanup.test.ts
+++ b/tests/unit/proxy/response-handler-abort-listener-cleanup.test.ts
@@ -110,7 +110,7 @@ function makeProvider(overrides: Partial<Provider> = {}): Provider {
   return {
     id: 99,
     name: "test-provider",
-    providerType: "openai",
+    providerType: "openai-compatible",
     baseUrl: "https://api.test.invalid",
     priority: 1,
     weight: 1,
@@ -166,7 +166,7 @@ function makeSession(clientAbortSignal: AbortSignal | null, stream: boolean): Pr
     sessionId: null,
     requestSequence: 1,
     originalFormat: "openai",
-    providerType: "openai",
+    providerType: "openai-compatible",
     originalModelName: "gpt-5.4",
     originalUrlPathname: "/v1/chat/completions",
     providerChain: [],
@@ -280,4 +280,26 @@ describe("ProxyResponseHandler client abort listener cleanup", () => {
     expect(removeSpy.mock.calls.filter(([type]) => type === "abort")).toHaveLength(0);
     expect(testState.cancelTask).toHaveBeenCalled();
   });
+
+  it("invokes stream cancel once when client signal is already aborted", async () => {
+    const controller = new AbortController();
+    controller.abort();
+    const addSpy = vi.spyOn(controller.signal, "addEventListener");
+    const removeSpy = vi.spyOn(controller.signal, "removeEventListener");
+    const session = makeSession(controller.signal, true);
+    const upstreamResponse = new Response(
+      'data: {"choices":[{"delta":{"content":"ok"}}]}\n\ndata: [DONE]\n\n',
+      {
+        headers: { "content-type": "text/event-stream" },
+      }
+    );
+
+    const response = await ProxyResponseHandler.dispatch(session, upstreamResponse);
+    await response.text();
+    await drainAsyncTasks();
+
+    expect(addSpy.mock.calls.filter(([type]) => type === "abort")).toHaveLength(0);
+    expect(removeSpy.mock.calls.filter(([type]) => type === "abort")).toHaveLength(0);
+    expect(testState.cancelTask).toHaveBeenCalledTimes(1);
+  });
 });