fix: prevent interrupt mode from replaying previous assistant reply

EC2 Default User · EC2 Default User · commit a1f0cdba669c · 2026-03-19T02:34:59.000Z
When messages.queue.mode is 'interrupt', aborting an active run causes the previous turn's assistant reply to be re-sent to the user. Root cause: buildEmbeddedRunPayloads falls back to extractAssistantText(lastAssistant) when assistantTexts is empty. After an abort, assistantTexts is empty but lastAssistant still references the previous turn's message from session history. Fix: 1. Guard lastAssistant fallback: pass undefined when aborted and no new assistant text was generated (run.ts) 2. Skip blockReplyPipeline flush and payload delivery entirely when the run was aborted (agent-runner.ts) Fixes #50145
diff --git a/src/agents/pi-embedded-runner/run.ts b/src/agents/pi-embedded-runner/run.ts
@@ -1605,7 +1605,8 @@ export async function runEmbeddedPiAgent(
           const payloads = buildEmbeddedRunPayloads({
             assistantTexts: attempt.assistantTexts,
             toolMetas: attempt.toolMetas,
-            lastAssistant: attempt.lastAssistant,
+            lastAssistant:
+              aborted && attempt.assistantTexts.length === 0 ? undefined : attempt.lastAssistant,
             lastToolError: attempt.lastToolError,
             config: params.config,
             sessionKey: params.sessionKey ?? params.sessionId,
diff --git a/src/auto-reply/reply/agent-runner.ts b/src/auto-reply/reply/agent-runner.ts
@@ -406,9 +406,14 @@ export async function runReplyAgent(params: {
     }
 
     const payloadArray = runResult.payloads ?? [];
+    const wasAborted = runResult.meta?.aborted === true;
 
     if (blockReplyPipeline) {
-      await blockReplyPipeline.flush({ force: true });
+      // Skip flushing buffered block replies when the run was aborted —
+      // the buffer may contain stale content from the interrupted turn.
+      if (!wasAborted) {
+        await blockReplyPipeline.flush({ force: true });
+      }
       blockReplyPipeline.stop();
     }
     if (pendingToolTasks.size > 0) {
@@ -478,6 +483,13 @@ export async function runReplyAgent(params: {
       cliSessionId,
     });
 
+    // When the run was aborted (e.g. by interrupt queue mode), skip payload
+    // delivery entirely. The aborted run's payloads may contain stale
+    // `lastAssistant` fallback text from a previous turn. (#50145)
+    if (wasAborted) {
+      return finalizeWithFollowup(undefined, queueKey, runFollowupTurn);
+    }
+
     // Drain any late tool/block deliveries before deciding there's "nothing to send".
     // Otherwise, a late typing trigger (e.g. from a tool callback) can outlive the run and
     // keep the typing indicator stuck.
