fix: propagate stream timeout abort reason (#76633)

CHANGELOG.md

@@ -25,6 +25,7 @@ Docs: https://docs.openclaw.ai
 - Plugins/tools: keep disabled bundled tool plugins out of explicit runtime allowlist ownership and fall back from loaded-but-empty channel registries to tool-bearing plugin registries, so Active Memory can use bundled `memory-core` search/get tools even when `memory-lancedb` is disabled. Fixes #76603. Thanks @jwong-art.
 - Plugins/install: run `npm install` from the managed npm-root manifest so installing one `@openclaw/*` plugin preserves already installed sibling plugins instead of pruning them. Fixes #76571. (#76602) Thanks @byungskers and @crpol.
 - Channels/QQ Bot: resolve structured `clientSecret` SecretRefs before QQ token exchange, expose the QQ Bot secret contract to secrets tooling, and reject legacy `secretref:/...` marker strings. (#74772) Thanks @xialonglee.
+- Agents: keep active streamed provider replies alive by refreshing guarded fetch timeouts on raw body chunks and surface true prompt stream timeouts as explicit errors instead of partial assistant fragments. Fixes #76307. (#76633) Thanks @MkDev11.
 - Plugins/externalization: keep official ACPX, Google Chat, and LINE install specs on production package names, leaving beta-tag probing to the explicit OpenClaw beta update channel. Thanks @vincentkoc.
 - CLI/doctor: keep missing-plugin repair from overriding official catalog metadata with runtime fallbacks, so ACPX repairs preserve the official npm spec during the externalization rollout. Thanks @vincentkoc.
 - CLI/doctor: match stale bundled-plugin install records by exact parsed package name so doctor does not remove external npm or ClawHub records that only share an OpenClaw package-name prefix.

src/agents/pi-embedded-runner/run/assistant-failover.test.ts

@@ -170,10 +170,9 @@ describe("handleAssistantFailover", () => {
 
     it("leaves plain timeouts on the continue_normal path for the runner's timeout-payload synthesis", async () => {
       // `run.ts` already emits an explicit timeout payload when
-      // `buildEmbeddedRunPayloads` produces no assistant content (see
-      // the `timedOut && !timedOutDuringCompaction &&
-      // !payloadsWithToolMedia.length` block). Throwing a FailoverError
-      // here would short-circuit that synthesis and break
+      // `buildEmbeddedRunPayloads` produces no assistant content or only a
+      // partial prompt-timeout fragment. Throwing a FailoverError here would
+      // short-circuit that synthesis and break
       // timeout-compaction retry coverage in
       // `run.timeout-triggered-compaction.test.ts`. The throw path is
       // reserved for concrete provider failures that have no other

src/utils/fetch-timeout.test.ts

@@ -1,3 +1,4 @@
+import { Stream } from "openai/streaming";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 const warn = vi.hoisted(() => vi.fn());
@@ -30,6 +31,10 @@ describe("buildTimeoutAbortSignal", () => {
     await vi.advanceTimersByTimeAsync(25);
 
     expect(signal?.aborted).toBe(true);
+    expect(signal?.reason).toMatchObject({
+      name: "TimeoutError",
+      message: "request timed out",
+    });
     expect(warn).toHaveBeenCalledTimes(1);
     expect(warn).toHaveBeenCalledWith(
       "fetch timeout reached; aborting operation",
@@ -45,6 +50,45 @@ describe("buildTimeoutAbortSignal", () => {
     cleanup();
   });
 
+  it("keeps timeout aborts visible to OpenAI SSE streams instead of cleanly ending", async () => {
+    const { signal, cleanup } = buildTimeoutAbortSignal({
+      timeoutMs: 25,
+      operation: "unit-test",
+    });
+    const encoder = new TextEncoder();
+    const response = new Response(
+      new ReadableStream({
+        start(controller) {
+          controller.enqueue(encoder.encode('data: {"ok": true}\n\n'));
+          signal?.addEventListener(
+            "abort",
+            () => controller.error(signal.reason ?? new Error("request timed out")),
+            { once: true },
+          );
+        },
+      }),
+      { headers: { "content-type": "text/event-stream" } },
+    );
+
+    const iterator = Stream.fromSSEResponse(response, new AbortController())[
+      Symbol.asyncIterator
+    ]();
+
+    await expect(iterator.next()).resolves.toMatchObject({
+      done: false,
+      value: { ok: true },
+    });
+    const pending = iterator.next().catch((error: unknown) => error);
+    await vi.advanceTimersByTimeAsync(25);
+
+    await expect(pending).resolves.toMatchObject({
+      name: "TimeoutError",
+      message: "request timed out",
+    });
+
+    cleanup();
+  });
+
   it("annotates timeout logs when the timer fires late", async () => {
     vi.setSystemTime(0);
     const { cleanup } = buildTimeoutAbortSignal({

src/utils/fetch-timeout.ts

@@ -87,7 +87,9 @@ function abortDueToTimeout(
     ...(operation ? { operation } : {}),
     ...(sanitizedUrl ? { url: sanitizedUrl } : {}),
   });
-  controller.abort();
+  const error = new Error("request timed out");
+  error.name = "TimeoutError";
+  controller.abort(error);
 }
 
 export function buildTimeoutAbortSignal(params: TimeoutAbortSignalParams): {