diff --git a/internal/cloud/code-agent-agentrun-adapter.ts b/internal/cloud/code-agent-agentrun-adapter.ts
index 06d8ee5d..4e58e99b 100644
--- a/internal/cloud/code-agent-agentrun-adapter.ts
+++ b/internal/cloud/code-agent-agentrun-adapter.ts
@@ -392,6 +392,22 @@ export async function submitAgentRunChatTurn({ params = {}, options = {}, traceI
       }
       throw error;
     }
+    const ensuredSessionRecord = agentRunSessionRecordFromEnsure(ensuredSession);
+    if (attempt === 0 && agentRunSessionThreadInvalidated(ensuredSessionRecord)) {
+      sessionReset = true;
+      traceStore.append(traceId, agentRunTraceEvent({
+        type: "backend",
+        status: "running",
+        label: "agentrun:profile-session-reset",
+        message: "AgentRun profile-scoped session " + sessionId + " is terminal after a thread/resume failure; hwlab-cloud-api will create a fresh profile sessionId instead of letting AgentRun manager backfill a stale threadId.",
+        sessionId,
+        previousSessionId: baseSessionId,
+        backendProfile,
+        waitingFor: "agentrun-session-reset",
+        valuesPrinted: false
+      }, backendProfile));
+      continue;
+    }
     const profileThreadId = agentRunSessionThreadIdFromEnsure(ensuredSession);
     const dispatchParams = paramsWithAgentRunSessionThread(attemptParams, profileThreadId);
     if (safeOpaqueId(attemptParams.threadId) && !profileThreadId) {