fix(memory): handle block-list content in remove_code_blocks

A custom LangChain LLM passed to AsyncMemory._create_procedural_memory
returns AIMessage.content, which is str | list[str | dict]. Providers
that emit content blocks hit content.strip() on a list and raised
AttributeError.

remove_code_blocks already normalized None, so the list case is handled
in the same guard rather than at the single call site.

Closes #6150

tests/test_memory.py

@@ -1235,9 +1235,10 @@ class TestHybridSearchWarning:
     def test_warning_for_store_without_keyword_search(
         self, mock_vs_factory, mock_emb, mock_llm, mock_sqlite, _cap, caplog
     ):
-        from mem0.vector_stores.base import VectorStoreBase
         import logging
 
+        from mem0.vector_stores.base import VectorStoreBase
+
         class StoreWithoutKeywordSearch(VectorStoreBase):
             def create_col(self, *a, **kw): pass
             def insert(self, *a, **kw): pass
@@ -1271,9 +1272,10 @@ class TestHybridSearchWarning:
     def test_no_warning_for_store_with_keyword_search(
         self, mock_vs_factory, mock_emb, mock_llm, mock_sqlite, _cap, caplog
     ):
-        from mem0.vector_stores.base import VectorStoreBase
         import logging
 
+        from mem0.vector_stores.base import VectorStoreBase
+
         class StoreWithKeywordSearch(VectorStoreBase):
             def keyword_search(self, query, top_k=5, filters=None):
                 return []
@@ -1536,6 +1538,39 @@ async def test_async_procedural_memory_langchain_strips_code_blocks(mock_llm_fac
     assert "```" not in stored_data
 
 
+@pytest.mark.asyncio
+@patch("mem0.memory.main.VectorStoreFactory")
+@patch("mem0.memory.main.EmbedderFactory")
+@patch("mem0.memory.main.LlmFactory")
+async def test_async_procedural_memory_langchain_block_list_content(mock_llm_factory, mock_emb, mock_vs):
+    """Regression #6150: block-list message content must not raise AttributeError."""
+    mock_vs.return_value = MagicMock()
+    mock_emb.return_value = MagicMock()
+    mock_emb.return_value.embed.return_value = [0.1] * 1536
+    mock_llm_factory.return_value = MagicMock()
+
+    from mem0.memory.main import AsyncMemory
+
+    config = MemoryConfig()
+    memory = AsyncMemory(config)
+    memory.vector_store = MagicMock()
+    memory.vector_store.insert = MagicMock()
+
+    mock_langchain_llm = MagicMock()
+    mock_response = MagicMock()
+    mock_response.content = [{"type": "text", "text": '```json\n{"key": "value"}\n```'}]
+    mock_langchain_llm.invoke.return_value = mock_response
+
+    messages = [{"role": "user", "content": "test"}]
+    metadata = {"user_id": "test_user"}
+
+    await memory._create_procedural_memory(messages, metadata=metadata, llm=mock_langchain_llm)
+
+    insert_call = memory.vector_store.insert.call_args
+    stored_data = insert_call[1]["payloads"][0]["data"]
+    assert stored_data == '{"key": "value"}'
+
+
 @pytest.mark.asyncio
 @patch("mem0.memory.main.VectorStoreFactory")
 @patch("mem0.memory.main.EmbedderFactory")