support SQLite checkpointer

Author: ks6088ts

.gitignore

@@ -168,3 +168,5 @@ generated/
 *.db
 *.wav
 mlartifacts
+*.sqlite
+*.bin

docs/references.md

@@ -20,6 +20,7 @@
 - [Add and manage memory](https://docs.langchain.com/oss/python/langgraph/add-memory)
 - [Persistence](https://langchain-ai.github.io/langgraph/concepts/persistence/)
 - [Chatbot with message summarization & external DB memory](https://github.com/langchain-ai/langchain-academy/blob/main/module-2/chatbot-external-memory.ipynb)
+- [LangGraph の会話履歴を SQLite に保持しよう](https://www.creationline.com/tech-blog/chatgpt-ai/75797)
 
 ### LangChain
 

pyproject.toml

@@ -27,6 +27,7 @@ dependencies = [
     "langchain-text-splitters>=0.3.9",
     "langfuse>=3.6.2",
     "langgraph>=0.6.2",
+    "langgraph-checkpoint-sqlite>=2.0.11",
     "langgraph-supervisor>=0.0.29",
     "mlflow>=3.4.0",
     "openai-whisper>=20250625",

template_langgraph/services/streamlits/pages/chat_with_tools_agent.py

@@ -1,5 +1,7 @@
 import os
+import sqlite3
 import tempfile
+import uuid
 from base64 import b64encode
 from dataclasses import dataclass
 
@@ -9,8 +11,8 @@
     StreamlitCallbackHandler,
 )
 from langfuse.langchain import CallbackHandler
-from langgraph.checkpoint.memory import InMemorySaver
-from langgraph.store.memory import InMemoryStore
+from langgraph.checkpoint.sqlite import SqliteSaver
+from langgraph.store.sqlite import SqliteStore
 
 from template_langgraph.agents.chat_with_tools_agent.agent import (
     AgentState,
@@ -20,6 +22,10 @@
 from template_langgraph.speeches.tts import TtsWrapper
 from template_langgraph.tools.common import get_default_tools
 
+checkpoints_conn = sqlite3.connect("checkpoints.sqlite", check_same_thread=False)
+store_conn = sqlite3.connect("store.sqlite", check_same_thread=False)
+thread_id = str(uuid.uuid4())
+
 
 def image_to_base64(image_bytes: bytes) -> str:
     return b64encode(image_bytes).decode("utf-8")
@@ -72,8 +78,12 @@ def ensure_agent_graph(selected_tools: list) -> None:
     if "graph" not in st.session_state or graph_signature != signature:
         st.session_state["graph"] = ChatWithToolsAgent(
             tools=selected_tools,
-            checkpointer=InMemorySaver(),  # You can replace this with a persistent checkpointer if needed
-            store=InMemoryStore(),  # You can replace this with a persistent store if needed
+            checkpointer=SqliteSaver(
+                conn=checkpoints_conn,
+            ),
+            store=SqliteStore(
+                conn=store_conn,
+            ),
         ).create_graph()
         st.session_state["graph_tools_signature"] = signature
 
@@ -311,7 +321,7 @@ def invoke_agent(graph_messages: list) -> AgentState:
                 CallbackHandler(),
             ],
             "configurable": {
-                "thread_id": "1",
+                "thread_id": thread_id,
                 "user_id": "user_1",
             },
         },