diff --git a/mem0-ts/src/oss/src/memory/index.ts b/mem0-ts/src/oss/src/memory/index.ts
index f41d161ac..ee653da46 100644
--- a/mem0-ts/src/oss/src/memory/index.ts
+++ b/mem0-ts/src/oss/src/memory/index.ts
@@ -1189,7 +1189,13 @@ export class Memory {
       }
     }
 
-    const result = { ...memoryItem, ...filters };
+    const result = {
+      ...memoryItem,
+      ...filters,
+      ...(memory.payload.attributedTo && {
+        attributedTo: memory.payload.attributedTo,
+      }),
+    };
     await this._displayFirstRunNotice("get");
     return result;
   }
@@ -1453,6 +1459,7 @@ export class Memory {
           ...(payload.user_id && { user_id: payload.user_id }),
           ...(payload.agent_id && { agent_id: payload.agent_id }),
           ...(payload.run_id && { run_id: payload.run_id }),
+          ...(payload.attributedTo && { attributedTo: payload.attributedTo }),
           ...(scored.scoreDetails && { score_details: scored.scoreDetails }),
         };
       });
@@ -1687,6 +1694,9 @@ export class Memory {
       ...(mem.payload.user_id && { user_id: mem.payload.user_id }),
       ...(mem.payload.agent_id && { agent_id: mem.payload.agent_id }),
       ...(mem.payload.run_id && { run_id: mem.payload.run_id }),
+      ...(mem.payload.attributedTo && {
+        attributedTo: mem.payload.attributedTo,
+      }),
     }));
 
     const result = { results };
diff --git a/mem0-ts/src/oss/src/types/index.ts b/mem0-ts/src/oss/src/types/index.ts
index f52bbdb97..422f208e1 100644
--- a/mem0-ts/src/oss/src/types/index.ts
+++ b/mem0-ts/src/oss/src/types/index.ts
@@ -82,6 +82,7 @@ export interface MemoryItem {
   updatedAt?: string;
   score?: number;
   metadata?: Record<string, any>;
+  attributedTo?: string;
 }
 
 export interface SearchFilters {
diff --git a/mem0-ts/src/oss/tests/memory.crud.test.ts b/mem0-ts/src/oss/tests/memory.crud.test.ts
index 7fb8d01d4..55db5d5f4 100644
--- a/mem0-ts/src/oss/tests/memory.crud.test.ts
+++ b/mem0-ts/src/oss/tests/memory.crud.test.ts
@@ -361,6 +361,45 @@ describe("Memory - search()", () => {
   });
 });
 
+// ─── attributedTo (#5666) ────────────────────────────────
+
+describe("Memory - attributedTo round-trip (#5666)", () => {
+  let memory: Memory;
+  const userId = `attributed_test_${Date.now()}`;
+  let id: string;
+
+  beforeAll(async () => {
+    memory = createMemory();
+    // The mocked LLM tags every extracted fact with attributed_to: "user".
+    const addResult: SearchResult = await memory.add("I love AI", { userId });
+    id = addResult.results[0].id;
+  });
+
+  afterAll(async () => {
+    await memory.reset();
+  });
+
+  test("get() surfaces attributedTo", async () => {
+    const item: MemoryItem | null = await memory.get(id);
+    expect(item!.attributedTo).toBe("user");
+  });
+
+  test("getAll() surfaces attributedTo", async () => {
+    const result: SearchResult = await memory.getAll({
+      filters: { user_id: userId },
+    });
+    expect(result.results[0].attributedTo).toBe("user");
+  });
+
+  test("search() surfaces attributedTo", async () => {
+    const result: SearchResult = await memory.search("AI", {
+      filters: { user_id: userId },
+    });
+    expect(result.results.length).toBeGreaterThan(0);
+    expect(result.results[0].attributedTo).toBe("user");
+  });
+});
+
 // ─── history() ───────────────────────────────────────────
 
 describe("Memory - history()", () => {