From 414affedd088b9323c29dff12e42f73034a3ca31 Mon Sep 17 00:00:00 2001
From: Charles Packer <packercharles@gmail.com>
Date: Fri, 16 Jan 2026 13:04:07 -0800
Subject: [PATCH] fix: prevent subagents from polluting LRU settings (#565)

Co-authored-by: Letta <noreply@letta.com>
---
 src/headless.ts | 22 +++++++++++++---------
 src/index.ts    | 20 ++++++++++++--------
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/headless.ts b/src/headless.ts
index 6a839e4..c09fe94 100644
--- a/src/headless.ts
+++ b/src/headless.ts
@@ -529,15 +529,19 @@ export async function handleHeadlessCommand(
   }
 
   // Save session (agent + conversation) to both project and global settings
-  await settingsManager.loadLocalProjectSettings();
-  settingsManager.setLocalLastSession(
-    { agentId: agent.id, conversationId },
-    process.cwd(),
-  );
-  settingsManager.setGlobalLastSession({
-    agentId: agent.id,
-    conversationId,
-  });
+  // Skip for subagents - they shouldn't pollute the LRU settings
+  const isSubagent = process.env.LETTA_CODE_AGENT_ROLE === "subagent";
+  if (!isSubagent) {
+    await settingsManager.loadLocalProjectSettings();
+    settingsManager.setLocalLastSession(
+      { agentId: agent.id, conversationId },
+      process.cwd(),
+    );
+    settingsManager.setGlobalLastSession({
+      agentId: agent.id,
+      conversationId,
+    });
+  }
 
   // Ensure the agent has the required skills blocks (for backwards compatibility)
   const createdBlocks = await ensureSkillsBlocks(agent.id);
diff --git a/src/index.ts b/src/index.ts
index 63a5ef8..0f2376d 100755
--- a/src/index.ts
+++ b/src/index.ts
@@ -1458,14 +1458,18 @@ async function main(): Promise<void> {
         }
 
         // Save the session (agent + conversation) to settings
-        settingsManager.setLocalLastSession(
-          { agentId: agent.id, conversationId: conversationIdToUse },
-          process.cwd(),
-        );
-        settingsManager.setGlobalLastSession({
-          agentId: agent.id,
-          conversationId: conversationIdToUse,
-        });
+        // Skip for subagents - they shouldn't pollute the LRU settings
+        const isSubagent = process.env.LETTA_CODE_AGENT_ROLE === "subagent";
+        if (!isSubagent) {
+          settingsManager.setLocalLastSession(
+            { agentId: agent.id, conversationId: conversationIdToUse },
+            process.cwd(),
+          );
+          settingsManager.setGlobalLastSession({
+            agentId: agent.id,
+            conversationId: conversationIdToUse,
+          });
+        }
 
         setAgentId(agent.id);
         setAgentState(agent);