diff --git a/extensions/memory-core/src/memory/manager-session-sync-ops.ts b/extensions/memory-core/src/memory/manager-session-sync-ops.ts
index 58f66e42487f..aa1c7b4abd52 100644
--- a/extensions/memory-core/src/memory/manager-session-sync-ops.ts
+++ b/extensions/memory-core/src/memory/manager-session-sync-ops.ts
@@ -230,7 +230,13 @@ export abstract class MemoryManagerSessionSyncOps extends MemoryManagerWatchOps
     }
     if (pending.length > 0) {
       this.sessionsDirty = true;
-      void this.sync({ reason: "session-delta" }).catch((err: unknown) => {
+      // Keep both identity and file keys so every transcript backend enters the
+      // targeted queue instead of letting an active sync clear this newer event.
+      void this.sync({
+        reason: "session-delta",
+        sessions: pendingTargets,
+        archiveFiles: pending,
+      }).catch((err: unknown) => {
         log.warn(`memory sync failed (session update): ${String(err)}`);
       });
     }
diff --git a/extensions/memory-core/src/memory/manager-session-update-race.test.ts b/extensions/memory-core/src/memory/manager-session-update-race.test.ts
new file mode 100644
index 000000000000..fff736b24ab1
--- /dev/null
+++ b/extensions/memory-core/src/memory/manager-session-update-race.test.ts
@@ -0,0 +1,99 @@
+import path from "node:path";
+import { DatabaseSync } from "node:sqlite";
+import type { MemorySessionSyncTarget } from "openclaw/plugin-sdk/memory-core-host-engine-storage";
+import { resolveOpenClawAgentSqlitePath } from "openclaw/plugin-sdk/sqlite-runtime";
+import { describe, expect, it, vi } from "vitest";
+import { createManagerIndexFixture } from "./manager-index.test-support.js";
+
+const { closeAllMemorySearchManagers, getMemorySearchManager } = await import("./index.js");
+
+describe("memory session update sync", () => {
+  const fixture = createManagerIndexFixture({
+    getMemorySearchManager,
+    closeAllMemorySearchManagers,
+  });
+  const { createConfig, getFreshManager, seedSessionTranscript } = fixture;
+
+  it("indexes an update that arrives before an active sync clears dirty state", async () => {
+    fixture.setStateDir(path.join(fixture.paths.workspace, ".state-session-update-during-sync"));
+    const sessionId = "session-update-during-sync";
+    const sessionKey = `agent:main:proof:${sessionId}`;
+    const updatedMarker = "UPDATE DURING ACTIVE SYNC 811";
+    const manager = await getFreshManager(
+      createConfig({ provider: "none", sources: ["sessions"], sessionMemory: true }),
+      "cli",
+    );
+    const owner = manager as unknown as {
+      queuedSessionSync: Promise<void> | null;
+      sessionPendingTargets: Map<string, MemorySessionSyncTarget>;
+      sessionsDirty: boolean;
+      sessionsReconcileDirty: boolean;
+      syncArchiveFiles: (params: unknown) => Promise<void>;
+      processSessionUpdateBatch: () => Promise<void>;
+    };
+    let releaseActiveSync = () => {};
+    const activeSyncGate = new Promise<void>((resolve) => {
+      releaseActiveSync = resolve;
+    });
+    let markActiveSyncIndexed = () => {};
+    const activeSyncIndexed = new Promise<void>((resolve) => {
+      markActiveSyncIndexed = resolve;
+    });
+    let syncArchiveFilesSpy: { mockRestore: () => void } | undefined;
+    try {
+      await seedSessionTranscript({
+        sessionId,
+        sessionKey,
+        messages: [{ role: "user", timestamp: Date.now(), content: "initial transcript" }],
+      });
+      await manager.sync({ reason: "test-baseline", force: true });
+
+      owner.sessionsDirty = true;
+      owner.sessionsReconcileDirty = true;
+      const syncArchiveFiles = owner.syncArchiveFiles.bind(manager);
+      syncArchiveFilesSpy = vi
+        .spyOn(owner, "syncArchiveFiles")
+        .mockImplementationOnce(async (params) => {
+          await syncArchiveFiles(params);
+          markActiveSyncIndexed();
+          await activeSyncGate;
+        });
+      const activeSync = manager.sync({ reason: "test-active" });
+      await activeSyncIndexed;
+
+      await seedSessionTranscript({
+        sessionId,
+        sessionKey,
+        messages: [{ role: "assistant", timestamp: Date.now(), content: updatedMarker }],
+      });
+      owner.sessionPendingTargets.set(sessionKey, { agentId: "main", sessionId, sessionKey });
+      await owner.processSessionUpdateBatch();
+      const queuedSessionSync = owner.queuedSessionSync;
+      expect(queuedSessionSync).not.toBeNull();
+
+      releaseActiveSync();
+      await activeSync;
+      await queuedSessionSync;
+
+      const observer = new DatabaseSync(resolveOpenClawAgentSqlitePath({ agentId: "main" }), {
+        readOnly: true,
+      });
+      try {
+        const row = observer
+          .prepare(
+            "SELECT COUNT(*) AS count FROM memory_index_chunks WHERE source = 'sessions' AND text LIKE ?",
+          )
+          .get(`%${updatedMarker}%`) as { count: number };
+        expect(row.count).toBeGreaterThan(0);
+      } finally {
+        observer.close();
+      }
+      expect(manager.status().dirty).toBe(false);
+    } finally {
+      syncArchiveFilesSpy?.mockRestore();
+      releaseActiveSync();
+      await manager.close?.();
+      fixture.restoreStateDir();
+    }
+  });
+});
diff --git a/extensions/memory-core/src/memory/manager-sync-ops.startup-catchup.test.ts b/extensions/memory-core/src/memory/manager-sync-ops.startup-catchup.test.ts
index 3b4bbb853f07..6fa4607b57a4 100644
--- a/extensions/memory-core/src/memory/manager-sync-ops.startup-catchup.test.ts
+++ b/extensions/memory-core/src/memory/manager-sync-ops.startup-catchup.test.ts
@@ -880,7 +880,8 @@ describe("session startup catch-up", () => {
     await Promise.resolve();
 
     expect(harness.getDirtyArchiveFiles()).toEqual([session.sessionKey]);
-    expect(harness.syncCalls).toEqual([{ reason: "session-delta" }]);
+    expect(harness.syncCalls[0]?.archiveFiles).toEqual([session.sessionKey]);
+    expect(harness.syncCalls[0]?.sessions).toHaveLength(1);
   });
 
   it("keeps targeted indexing on the SQLite store resolved by its corpus snapshot", async () => {
@@ -1063,7 +1064,7 @@ describe("session startup catch-up", () => {
         await harness.waitForSessionSync();
 
         expect(harness.getDirtyArchiveFiles()).toEqual([session.filePath]);
-        expect(harness.syncCalls).toEqual([{ reason: "session-delta" }]);
+        expect(harness.syncCalls[0]?.archiveFiles).toEqual([session.filePath]);
         expect(harness.indexedPaths).toEqual([
           `sessions/main/thread.jsonl.${reason}.2026-06-23T10-00-00.000Z`,
         ]);