fix: address code review feedback on LangGraph checkpoint PR

- Fix sync/async section comment headers in ots_backend.py and session_store.py
- Add langgraph optional dependency in pyproject.toml
- Improve build_ots_clients return type annotation with TYPE_CHECKING import
- Handle missing state table gracefully in init_search_index

Made-with: Cursor

Author: TJKkking

agentrun/conversation_service/ots_backend.py

@@ -2542,7 +2542,7 @@ async def delete_state_row_async(
         await self._async_client.delete_row(table_name, row, condition)
 
     # -----------------------------------------------------------------------
-    # Checkpoint CRUD（LangGraph）（异步）
+    # State CRUD（同步）
     # -----------------------------------------------------------------------
 
     def delete_state_row(
@@ -2561,7 +2561,7 @@ def delete_state_row(
         self._client.delete_row(table_name, row, condition)
 
     # -----------------------------------------------------------------------
-    # Checkpoint CRUD（LangGraph）（同步）
+    # Checkpoint CRUD（LangGraph）（异步）
     # -----------------------------------------------------------------------
 
     async def put_checkpoint_async(
@@ -2591,6 +2591,10 @@ async def put_checkpoint_async(
         condition = Condition(RowExistenceExpectation.IGNORE)
         await self._async_client.put_row(self._checkpoint_table, row, condition)
 
+    # -----------------------------------------------------------------------
+    # Checkpoint CRUD（LangGraph）（同步）
+    # -----------------------------------------------------------------------
+
     def put_checkpoint(
         self,
         thread_id: str,

agentrun/conversation_service/session_store.py

@@ -134,7 +134,7 @@ async def init_langgraph_tables_async(self) -> None:
         await self._backend.init_checkpoint_tables_async()
 
     # -------------------------------------------------------------------
-    # Checkpoint 管理（LangGraph）（异步）
+    # Checkpoint 管理（LangGraph）（同步）
     # -------------------------------------------------------------------
 
     def init_langgraph_tables(self) -> None:
@@ -149,7 +149,7 @@ def init_langgraph_tables(self) -> None:
         self._backend.init_checkpoint_tables()
 
     # -------------------------------------------------------------------
-    # Checkpoint 管理（LangGraph）（同步）
+    # Checkpoint 管理（LangGraph）（异步）
     # -------------------------------------------------------------------
 
     async def put_checkpoint_async(
@@ -366,7 +366,7 @@ async def delete_thread_checkpoints_async(
         await self._backend.delete_thread_checkpoints_async(thread_id)
 
     # -------------------------------------------------------------------
-    # Session 管理（异步）/ Session management (async)
+    # Checkpoint 清理（同步）
     # -------------------------------------------------------------------
 
     def delete_thread_checkpoints(
@@ -377,7 +377,7 @@ def delete_thread_checkpoints(
         self._backend.delete_thread_checkpoints(thread_id)
 
     # -------------------------------------------------------------------
-    # Session 管理（同步）/ Session management (async)
+    # Session 管理（异步）/ Session management (async)
     # -------------------------------------------------------------------
 
     async def create_session_async(
@@ -426,6 +426,10 @@ async def create_session_async(
         await self._backend.put_session_async(session)
         return session
 
+    # -------------------------------------------------------------------
+    # Session 管理（同步）/ Session management (sync)
+    # -------------------------------------------------------------------
+
     def create_session(
         self,
         agent_id: str,

agentrun/conversation_service/utils.py

@@ -7,7 +7,13 @@
 
 import json
 import time
-from typing import Any
+from typing import Any, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from tablestore import (
+        AsyncOTSClient,  # type: ignore[import-untyped]
+        OTSClient,
+    )
 
 # OTS 单个属性列值上限为 2MB，留 0.5MB 余量（按字符数计）
 MAX_COLUMN_SIZE: int = 1_500_000  # 1.5M 字符
@@ -106,7 +112,7 @@ def build_ots_clients(
     instance_name: str,
     *,
     sts_token: str | None = None,
-) -> tuple[Any, Any]:
+) -> tuple[OTSClient, AsyncOTSClient]:
     """构建 OTSClient 和 AsyncOTSClient 实例。
 
     独立于 codegen 模板，避免 AsyncOTSClient 被替换为 OTSClient。

pyproject.toml

@@ -63,6 +63,11 @@ tablestore = [
     "tablestore>=6.1.0",
 ]
 
+langgraph = [
+    "langgraph>=0.2.0; python_version >= '3.10'",
+    "langchain-core>=0.3.0; python_version >= '3.10'",
+]
+
 [dependency-groups]
 dev = [
     "coverage>=7.10.7",