From f58dd0f9b6ae21e72e6ed2413a83f292b1a391bc Mon Sep 17 00:00:00 2001
From: FullerStackDev <263060202+fuller-stack-dev@users.noreply.github.com>
Date: Tue, 21 Apr 2026 16:16:34 -0600
Subject: [PATCH] fix(agents): harden replay normalization guards

---
 src/agents/pi-embedded-runner/replay-history.ts |  7 +++++++
 src/agents/pi-embedded-runner/run/attempt.ts    | 10 ++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/agents/pi-embedded-runner/replay-history.ts b/src/agents/pi-embedded-runner/replay-history.ts
index 25b156998dd..cb0985cd0c3 100644
--- a/src/agents/pi-embedded-runner/replay-history.ts
+++ b/src/agents/pi-embedded-runner/replay-history.ts
@@ -40,6 +40,7 @@ import {
   type AssistantUsageSnapshot,
   type UsageLike,
 } from "../usage.js";
+import { log } from "./logger.js";
 import { dropThinkingBlocks } from "./thinking.js";
 
 const INTER_SESSION_PREFIX_BASE = "[Inter-session message]";
@@ -235,6 +236,12 @@ export function normalizeAssistantReplayContent(messages: AgentMessage[]): Agent
     if (!message || message.role !== "assistant" || Array.isArray(message.content)) {
       continue;
     }
+    if (typeof message.content !== "string") {
+      log.warn(
+        `normalizeAssistantReplayContent: repairing malformed assistant content ` +
+          `(index=${i}, type=${typeof message.content})`,
+      );
+    }
     out[i] = {
       ...(message as unknown as Record<string, unknown>),
       content:
diff --git a/src/agents/pi-embedded-runner/run/attempt.ts b/src/agents/pi-embedded-runner/run/attempt.ts
index c462873b94c..01ab6984ba2 100644
--- a/src/agents/pi-embedded-runner/run/attempt.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.ts
@@ -1144,9 +1144,11 @@ export async function runEmbeddedAttempt(
         throw new Error("Embedded agent session missing");
       }
       const activeSession = session;
-      const baseConvertToLlm = activeSession.agent.convertToLlm.bind(activeSession.agent);
-      activeSession.agent.convertToLlm = async (messages) =>
-        await baseConvertToLlm(normalizeAssistantReplayContent(messages));
+      if (typeof activeSession.agent.convertToLlm === "function") {
+        const baseConvertToLlm = activeSession.agent.convertToLlm.bind(activeSession.agent);
+        activeSession.agent.convertToLlm = async (messages) =>
+          await baseConvertToLlm(normalizeAssistantReplayContent(messages));
+      }
       let prePromptMessageCount = activeSession.messages.length;
       abortSessionForYield = () => {
         yieldAbortSettled = Promise.resolve(activeSession.abort());
@@ -2193,7 +2195,7 @@ export async function runEmbeddedAttempt(
               activeSession.agent.state.messages = normalizedReplayMessages;
             }
             finalPromptText = effectivePrompt;
-            const btwSnapshotMessages = activeSession.messages.slice(-MAX_BTW_SNAPSHOT_MESSAGES);
+            const btwSnapshotMessages = normalizedReplayMessages.slice(-MAX_BTW_SNAPSHOT_MESSAGES);
             updateActiveEmbeddedRunSnapshot(params.sessionId, {
               transcriptLeafId,
               messages: btwSnapshotMessages,