diff --git a/scripts/src/hwlab-node-web-observe-runner-source.ts b/scripts/src/hwlab-node-web-observe-runner-source.ts
index 64ff2234..40db6596 100644
--- a/scripts/src/hwlab-node-web-observe-runner-source.ts
+++ b/scripts/src/hwlab-node-web-observe-runner-source.ts
@@ -367,6 +367,7 @@ async function workbenchSessionSnapshot() {
 async function sendPrompt(text) {
   if (text.trim().length === 0) throw new Error("sendPrompt requires non-empty text");
   const beforeUrl = currentPageUrl();
+  const beforeEvidence = await promptSideEffectSnapshot();
   const primaryEditor = page.locator("#command-input").last();
   const editor = await primaryEditor.isVisible().catch(() => false)
     ? primaryEditor
@@ -407,6 +408,17 @@ async function sendPrompt(text) {
   const chatResponse = await chatResponsePromise;
   await page.waitForTimeout(500);
   if (chatResponse?.waitError) {
+    const sideEffect = await waitForPromptSideEffect(beforeEvidence, 12000);
+    if (sideEffect.submitted) {
+      return {
+        beforeUrl,
+        afterUrl: currentPageUrl(),
+        textHash: sha256Text(text),
+        textBytes: Buffer.byteLength(text),
+        chatSubmit: { status: null, statusText: null, urlPath: "/v1/agent/chat", waitError: chatResponse.waitError, sideEffectObserved: true, sideEffect },
+        pageId
+      };
+    }
     throw new Error("sendPrompt did not observe POST /v1/agent/chat response after submit: " + (chatResponse.waitError.message || chatResponse.waitError.name || "timeout"));
   }
   const chatStatus = chatResponse.status();
@@ -422,6 +434,47 @@ async function sendPrompt(text) {
   return { beforeUrl, afterUrl: currentPageUrl(), textHash: sha256Text(text), textBytes: Buffer.byteLength(text), chatSubmit: { status: chatStatus, statusText: chatResponse.statusText(), urlPath: chatUrlPath }, pageId };
 }
 
+async function waitForPromptSideEffect(beforeEvidence, timeoutMs) {
+  await page.waitForFunction((before) => {
+    const current = (() => {
+      const text = document.body?.innerText || "";
+      const runIds = Array.from(new Set(text.match(/run_[A-Za-z0-9_:-]+/gu) || [])).slice(-20);
+      const traceIds = Array.from(new Set(text.match(/trc_[A-Za-z0-9_:-]+/gu) || [])).slice(-20);
+      const running = /Trace running|最近\s*\d+\s*(?:秒|分钟|分|小时)前|Code Agent\s*耗时/iu.test(text);
+      const executionError = /AgentRun error|agentrun:error:|provider-stream-disconnected|provider-unavailable/iu.test(text);
+      const textBytes = new TextEncoder().encode(text).length;
+      return { runIds, traceIds, running, executionError, textBytes };
+    })();
+    const beforeRuns = Array.isArray(before?.runIds) ? before.runIds : [];
+    const beforeTraces = Array.isArray(before?.traceIds) ? before.traceIds : [];
+    const newRun = current.runIds.some((id) => !beforeRuns.includes(id));
+    const newTrace = current.traceIds.some((id) => !beforeTraces.includes(id));
+    const meaningfulChange = Math.abs(current.textBytes - Number(before?.textBytes || 0)) > 20 && (current.running || current.executionError);
+    return newRun || newTrace || meaningfulChange;
+  }, beforeEvidence || {}, { timeout: timeoutMs }).catch(() => null);
+  const after = await promptSideEffectSnapshot();
+  const beforeRuns = Array.isArray(beforeEvidence?.runIds) ? beforeEvidence.runIds : [];
+  const beforeTraces = Array.isArray(beforeEvidence?.traceIds) ? beforeEvidence.traceIds : [];
+  const newRunIds = after.runIds.filter((id) => !beforeRuns.includes(id));
+  const newTraceIds = after.traceIds.filter((id) => !beforeTraces.includes(id));
+  const meaningfulChange = Math.abs(after.textBytes - Number(beforeEvidence?.textBytes || 0)) > 20 && (after.running || after.executionError);
+  return { ...after, newRunIds, newTraceIds, submitted: newRunIds.length > 0 || newTraceIds.length > 0 || meaningfulChange, valuesRedacted: true };
+}
+
+async function promptSideEffectSnapshot() {
+  return page.evaluate(() => {
+    const text = document.body?.innerText || "";
+    return {
+      runIds: Array.from(new Set(text.match(/run_[A-Za-z0-9_:-]+/gu) || [])).slice(-20),
+      traceIds: Array.from(new Set(text.match(/trc_[A-Za-z0-9_:-]+/gu) || [])).slice(-20),
+      running: /Trace running|最近\s*\d+\s*(?:秒|分钟|分|小时)前|Code Agent\s*耗时/iu.test(text),
+      executionError: /AgentRun error|agentrun:error:|provider-stream-disconnected|provider-unavailable/iu.test(text),
+      textBytes: new TextEncoder().encode(text).length,
+      valuesRedacted: true
+    };
+  }).catch(() => ({ runIds: [], traceIds: [], running: false, executionError: false, textBytes: 0, valuesRedacted: true }));
+}
+
 async function selectProvider(provider) {
   const target = String(provider || "").trim();
   if (!target) throw new Error("selectProvider requires provider name");