以编程方式使用文档

AI 应用需要 记忆 在多次交互中共享上下文。在 LangGraph 中,你可以添加两种类型的记忆:

添加短期记忆

Short-term 记忆(线程级 持久化)使智能体能够跟踪多轮对话。要添加短期记忆:

from langgraph.checkpoint.memory import InMemorySaver  # [!code highlight]
from langgraph.graph import StateGraph

checkpointer = InMemorySaver()  # [!code highlight]

builder = StateGraph(...)
graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

graph.invoke(
    {"messages": [{"role": "user", "content": "hi! i am Bob"}]},
    {"configurable": {"thread_id": "1"}},  # [!code highlight]
)

生产环境使用

在生产环境中,使用由数据库支持的检查点器:

from langgraph.checkpoint.postgres import PostgresSaver

DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"
with PostgresSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
    builder = StateGraph(...)
    graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

Example: using Postgres checkpointer

  pip install -U "psycopg[binary,pool]" langgraph langgraph-checkpoint-postgres
  

Sync

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.postgres import PostgresSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"
      with PostgresSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # checkpointer.setup()

          def call_model(state: MessagesState):
              response = model.invoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

Async

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"
      async with AsyncPostgresSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # await checkpointer.setup()

          async def call_model(state: MessagesState):
              response = await model.ainvoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

Example: using MongoDB checkpointer

  pip install -U pymongo langgraph langgraph-checkpoint-mongodb
  

Sync

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.mongodb import MongoDBSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      MONGODB_URI = "localhost:27017"
      with MongoDBSaver.from_conn_string(MONGODB_URI) as checkpointer:  # [!code highlight]

          def call_model(state: MessagesState):
              response = model.invoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

Async

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.mongodb.aio import AsyncMongoDBSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      MONGODB_URI = "localhost:27017"
      async with AsyncMongoDBSaver.from_conn_string(MONGODB_URI) as checkpointer:  # [!code highlight]

          async def call_model(state: MessagesState):
              response = await model.ainvoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

Example: using Redis checkpointer

  pip install -U langgraph langgraph-checkpoint-redis
  

Sync

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.redis import RedisSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "redis://localhost:6379"
      with RedisSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # checkpointer.setup()

          def call_model(state: MessagesState):
              response = model.invoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)
      

Async

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.redis.aio import AsyncRedisSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "redis://localhost:6379"
      async with AsyncRedisSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # await checkpointer.asetup()

          async def call_model(state: MessagesState):
              response = await model.ainvoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

Example: using Oracle checkpointer

  pip install -U langgraph langgraph-oracledb
  

Sync

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph_oracledb.checkpoint.oracle import OracleSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "user/password@localhost:1521/FREEPDB1"
      with OracleSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # checkpointer.setup()

          def call_model(state: MessagesState):
              response = model.invoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              print(snapshot)

Async

      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph_oracledb.checkpoint.oracle import AsyncOracleSaver  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")

      DB_URI = "user/password@localhost:1521/FREEPDB1"
      async with AsyncOracleSaver.from_conn_string(DB_URI) as checkpointer:  # [!code highlight]
          # await checkpointer.setup()

          async def call_model(state: MessagesState):
              response = await model.ainvoke(state["messages"])
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

          config = {
              "configurable": {
                  "thread_id": "1"  # [!code highlight]
              }
          }

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what's my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

在子图中的使用

如果你的图包含 子图,你只需要在编译父图时提供检查点器。LangGraph 会自动将检查点器传播到子图。

from langgraph.graph import START, StateGraph
from langgraph.checkpoint.memory import InMemorySaver
from typing import TypedDict

class State(TypedDict):
    foo: str

# Subgraph

def subgraph_node_1(state: State):
    return {"foo": state["foo"] + "bar"}

subgraph_builder = StateGraph(State)
subgraph_builder.add_node(subgraph_node_1)
subgraph_builder.add_edge(START, "subgraph_node_1")
subgraph = subgraph_builder.compile()  # [!code highlight]

# Parent graph

builder = StateGraph(State)
builder.add_node("node_1", subgraph)  # [!code highlight]
builder.add_edge(START, "node_1")

checkpointer = InMemorySaver()
graph = builder.compile(checkpointer=checkpointer)  # [!code highlight]

你可以配置子图特定的检查点行为。参见 子图持久化 了解更多关于持久化级别的信息,包括中断支持和有状态延续。

subgraph_builder = StateGraph(...)
subgraph = subgraph_builder.compile(checkpointer=True)  # [!code highlight]

添加长期记忆

使用长期记忆来在多个对话之间存储用户特定或应用特定的数据。

from langgraph.store.memory import InMemoryStore  # [!code highlight]
from langgraph.graph import StateGraph

store = InMemoryStore()  # [!code highlight]

builder = StateGraph(...)
graph = builder.compile(store=store)  # [!code highlight]

在节点内访问 store

一旦你使用 store 编译了图,LangGraph 会自动将 store 注入到你的节点函数中。访问 store 的推荐方式是通过 Runtime object.

from dataclasses import dataclass
from langgraph.runtime import Runtime
from langgraph.graph import StateGraph, MessagesState, START


@dataclass
class Context:
    user_id: str

async def call_model(state: MessagesState, runtime: Runtime[Context]):  # [!code highlight]
    user_id = runtime.context.user_id  # [!code highlight]
    namespace = (user_id, "memories")

    # Search for relevant memories
    memories = await runtime.store.asearch(  # [!code highlight]
        namespace, query=state["messages"][-1].content, limit=3
    )
    info = "\n".join([d.value["data"] for d in memories])

    # ... Use memories in model call

    # Store a new memory
    await runtime.store.aput(  # [!code highlight]
        namespace, str(uuid.uuid4()), {"data": "User prefers dark mode"}
    )

builder = StateGraph(MessagesState, context_schema=Context)  # [!code highlight]
builder.add_node(call_model)
builder.add_edge(START, "call_model")
graph = builder.compile(store=store)

# Pass context at invocation time
graph.invoke(
    {"messages": [{"role": "user", "content": "hi"}]},
    {"configurable": {"thread_id": "1"}},
    context=Context(user_id="1"),  # [!code highlight]
)

生产环境使用

在生产环境中,使用由数据库支持的存储:

from langgraph.store.postgres import PostgresStore

DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"
with PostgresStore.from_conn_string(DB_URI) as store:  # [!code highlight]
    builder = StateGraph(...)
    graph = builder.compile(store=store)  # [!code highlight]

Example: using Postgres store

  pip install -U "psycopg[binary,pool]" langgraph langgraph-checkpoint-postgres
  

Async

      from dataclasses import dataclass
      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
      from langgraph.store.postgres.aio import AsyncPostgresStore  # [!code highlight]
      from langgraph.runtime import Runtime  # [!code highlight]


      model = init_chat_model(model="claude-haiku-4-5-20251001")

      @dataclass
      class Context:
          user_id: str

      async def call_model(  # [!code highlight]
          state: MessagesState,
          runtime: Runtime[Context],  # [!code highlight]
      ):
          user_id = runtime.context.user_id  # [!code highlight]
          namespace = ("memories", user_id)
          memories = await runtime.store.asearch(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
          info = "\n".join([d.value["data"] for d in memories])
          system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

          # Store new memories if the user asks the model to remember
          last_message = state["messages"][-1]
          if "remember" in last_message.content.lower():
              memory = "User name is Bob"
              await runtime.store.aput(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

          response = await model.ainvoke(
              [{"role": "system", "content": system_msg}] + state["messages"]
          )
          return {"messages": response}

      DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"

      async with (
          AsyncPostgresStore.from_conn_string(DB_URI) as store,  # [!code highlight]
          AsyncPostgresSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          # await store.setup()
          # await checkpointer.setup()

          builder = StateGraph(MessagesState, context_schema=Context)  # [!code highlight]
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {"configurable": {"thread_id": "1"}}
          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

          config = {"configurable": {"thread_id": "2"}}
          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          async for message in stream.messages:
              async for token in message.text:
                  print(token, end="", flush=True)

Sync

      from dataclasses import dataclass
      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.postgres import PostgresSaver
      from langgraph.store.postgres import PostgresStore  # [!code highlight]
      from langgraph.runtime import Runtime  # [!code highlight]


      model = init_chat_model(model="claude-haiku-4-5-20251001")

      @dataclass
      class Context:
          user_id: str

      def call_model(  # [!code highlight]
          state: MessagesState,
          runtime: Runtime[Context],  # [!code highlight]
      ):
          user_id = runtime.context.user_id  # [!code highlight]
          namespace = ("memories", user_id)
          memories = runtime.store.search(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
          info = "\n".join([d.value["data"] for d in memories])
          system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

          # Store new memories if the user asks the model to remember
          last_message = state["messages"][-1]
          if "remember" in last_message.content.lower():
              memory = "User name is Bob"
              runtime.store.put(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

          response = model.invoke(
              [{"role": "system", "content": system_msg}] + state["messages"]
          )
          return {"messages": response}

      DB_URI = "postgresql://postgres:postgres@localhost:5432/postgres?sslmode=disable"

      with (
          PostgresStore.from_conn_string(DB_URI) as store,  # [!code highlight]
          PostgresSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          # store.setup()
          # checkpointer.setup()

          builder = StateGraph(MessagesState, context_schema=Context)  # [!code highlight]
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {"configurable": {"thread_id": "1"}}
          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          for snapshot in stream.values:
              print(snapshot)

          config = {"configurable": {"thread_id": "2"}}
          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          for snapshot in stream.values:
              print(snapshot)

Example: using MongoDB store

Example: using Redis store

  pip install -U langgraph langgraph-checkpoint-redis
  

Async

      from dataclasses import dataclass
      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.redis.aio import AsyncRedisSaver
      from langgraph.store.redis.aio import AsyncRedisStore  # [!code highlight]
      from langgraph.runtime import Runtime  # [!code highlight]


      model = init_chat_model(model="claude-haiku-4-5-20251001")

      @dataclass
      class Context:
          user_id: str

      async def call_model(  # [!code highlight]
          state: MessagesState,
          runtime: Runtime[Context],  # [!code highlight]
      ):
          user_id = runtime.context.user_id  # [!code highlight]
          namespace = ("memories", user_id)
          memories = await runtime.store.asearch(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
          info = "\n".join([d.value["data"] for d in memories])
          system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

          # Store new memories if the user asks the model to remember
          last_message = state["messages"][-1]
          if "remember" in last_message.content.lower():
              memory = "User name is Bob"
              await runtime.store.aput(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

          response = await model.ainvoke(
              [{"role": "system", "content": system_msg}] + state["messages"]
          )
          return {"messages": response}

      DB_URI = "redis://localhost:6379"

      async with (
          AsyncRedisStore.from_conn_string(DB_URI) as store,  # [!code highlight]
          AsyncRedisSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          # await store.setup()
          # await checkpointer.asetup()

          builder = StateGraph(MessagesState, context_schema=Context)  # [!code highlight]
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {"configurable": {"thread_id": "1"}}
          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          async for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

          config = {"configurable": {"thread_id": "2"}}
          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          async for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

Sync

      from dataclasses import dataclass
      from langchain.chat_models import init_chat_model
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.checkpoint.redis import RedisSaver
      from langgraph.store.redis import RedisStore  # [!code highlight]
      from langgraph.runtime import Runtime  # [!code highlight]


      model = init_chat_model(model="claude-haiku-4-5-20251001")

      @dataclass
      class Context:
          user_id: str

      def call_model(  # [!code highlight]
          state: MessagesState,
          runtime: Runtime[Context],  # [!code highlight]
      ):
          user_id = runtime.context.user_id  # [!code highlight]
          namespace = ("memories", user_id)
          memories = runtime.store.search(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
          info = "\n".join([d.value["data"] for d in memories])
          system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

          # Store new memories if the user asks the model to remember
          last_message = state["messages"][-1]
          if "remember" in last_message.content.lower():
              memory = "User name is Bob"
              runtime.store.put(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

          response = model.invoke(
              [{"role": "system", "content": system_msg}] + state["messages"]
          )
          return {"messages": response}

      DB_URI = "redis://localhost:6379"

      with (
          RedisStore.from_conn_string(DB_URI) as store,  # [!code highlight]
          RedisSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          store.setup()
          checkpointer.setup()

          builder = StateGraph(MessagesState, context_schema=Context)  # [!code highlight]
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {"configurable": {"thread_id": "1"}}
          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

          config = {"configurable": {"thread_id": "2"}}
          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,
              version="v3",
              context=Context(user_id="1"),  # [!code highlight]
          )
          for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

Example: using Oracle store

  pip install -U langgraph langgraph-oracledb langchain-openai
  

Sync

      from langchain.chat_models import init_chat_model
      from langchain.embeddings import init_embeddings
      from langchain_core.runnables import RunnableConfig
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.store.base import BaseStore
      from langgraph_oracledb.checkpoint.oracle import OracleSaver
      from langgraph_oracledb.store.oracle import OracleStore  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")
      embeddings = init_embeddings("openai:text-embedding-3-small")

      DB_URI = "user/password@localhost:1521/FREEPDB1"

      with (
          OracleStore.from_conn_string(  # [!code highlight]
              DB_URI,
              index={"embed": embeddings, "dims": 1536},  # [!code highlight]
          ) as store,
          OracleSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          store.setup()
          checkpointer.setup()

          def call_model(
              state: MessagesState,
              config: RunnableConfig,
              *,
              store: BaseStore,  # [!code highlight]
          ):
              user_id = config["configurable"]["user_id"]
              namespace = ("memories", user_id)
              memories = store.search(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
              info = "\n".join([d.value["data"] for d in memories])
              system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

              # Store new memories if the user asks the model to remember
              last_message = state["messages"][-1]
              if "remember" in last_message.content.lower():
                  memory = "User name is Bob"
                  store.put(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

              response = model.invoke(
                  [{"role": "system", "content": system_msg}] + state["messages"]
              )
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {
              "configurable": {
                  "thread_id": "1",  # [!code highlight]
                  "user_id": "1",  # [!code highlight]
              }
          }
          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

          config = {
              "configurable": {
                  "thread_id": "2",  # [!code highlight]
                  "user_id": "1",
              }
          }

          stream = graph.stream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

Async

      from langchain.chat_models import init_chat_model
      from langchain.embeddings import init_embeddings
      from langchain_core.runnables import RunnableConfig
      from langgraph.graph import StateGraph, MessagesState, START
      from langgraph.store.base import BaseStore
      from langgraph_oracledb.checkpoint.oracle import AsyncOracleSaver
      from langgraph_oracledb.store.oracle import AsyncOracleStore  # [!code highlight]

      model = init_chat_model(model="claude-haiku-4-5-20251001")
      embeddings = init_embeddings("openai:text-embedding-3-small")

      DB_URI = "user/password@localhost:1521/FREEPDB1"

      async with (
          AsyncOracleStore.from_conn_string(  # [!code highlight]
              DB_URI,
              index={"embed": embeddings, "dims": 1536},  # [!code highlight]
          ) as store,
          AsyncOracleSaver.from_conn_string(DB_URI) as checkpointer,
      ):
          await store.setup()
          await checkpointer.setup()

          async def call_model(
              state: MessagesState,
              config: RunnableConfig,
              *,
              store: BaseStore,  # [!code highlight]
          ):
              user_id = config["configurable"]["user_id"]
              namespace = ("memories", user_id)
              memories = await store.asearch(namespace, query=str(state["messages"][-1].content))  # [!code highlight]
              info = "\n".join([d.value["data"] for d in memories])
              system_msg = f"You are a helpful assistant talking to the user. User info: {info}"

              # Store new memories if the user asks the model to remember
              last_message = state["messages"][-1]
              if "remember" in last_message.content.lower():
                  memory = "User name is Bob"
                  await store.aput(namespace, str(uuid.uuid4()), {"data": memory})  # [!code highlight]

              response = await model.ainvoke(
                  [{"role": "system", "content": system_msg}] + state["messages"]
              )
              return {"messages": response}

          builder = StateGraph(MessagesState)
          builder.add_node(call_model)
          builder.add_edge(START, "call_model")

          graph = builder.compile(
              checkpointer=checkpointer,
              store=store,  # [!code highlight]
          )

          config = {
              "configurable": {
                  "thread_id": "1",  # [!code highlight]
                  "user_id": "1",  # [!code highlight]
              }
          }
          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "Hi! Remember: my name is Bob"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

          config = {
              "configurable": {
                  "thread_id": "2",  # [!code highlight]
                  "user_id": "1",
              }
          }

          stream = await graph.astream_events(
              {"messages": [{"role": "user", "content": "what is my name?"}]},
              config,  # [!code highlight]
              version="v3",
          )
          async for snapshot in stream.values:
              snapshot["messages"][-1].pretty_print()

使用语义搜索

在图形的内存存储中启用语义搜索,让图形代理按语义相似度搜索存储中的项目。

from langchain.embeddings import init_embeddings
from langgraph.store.memory import InMemoryStore

# Create store with semantic search enabled
embeddings = init_embeddings("openai:text-embedding-3-small")
store = InMemoryStore(
    index={
        "embed": embeddings,
        "dims": 1536,
    }
)

store.put(("user_123", "memories"), "1", {"text": "I love pizza"})
store.put(("user_123", "memories"), "2", {"text": "I am a plumber"})

items = store.search(
    ("user_123", "memories"), query="I'm hungry", limit=1
)

Long-term memory with semantic search

    from langchain.embeddings import init_embeddings
    from langchain.chat_models import init_chat_model
    from langgraph.store.memory import InMemoryStore
    from langgraph.graph import START, MessagesState, StateGraph
    from langgraph.runtime import Runtime  # [!code highlight]

    model = init_chat_model("gpt-5.4-mini")

    # Create store with semantic search enabled
    embeddings = init_embeddings("openai:text-embedding-3-small")
    store = InMemoryStore(
        index={
            "embed": embeddings,
            "dims": 1536,
        }
    )

    store.put(("user_123", "memories"), "1", {"text": "I love pizza"})
    store.put(("user_123", "memories"), "2", {"text": "I am a plumber"})

    async def chat(state: MessagesState, runtime: Runtime):  # [!code highlight]
        # Search based on user's last message
        items = await runtime.store.asearch(  # [!code highlight]
            ("user_123", "memories"), query=state["messages"][-1].content, limit=2
        )
        memories = "\n".join(item.value["text"] for item in items)
        memories = f"## Memories of user\n{memories}" if memories else ""
        response = await model.ainvoke(
            [
                {"role": "system", "content": f"You are a helpful assistant.\n{memories}"},
                *state["messages"],
            ]
        )
        return {"messages": [response]}


    builder = StateGraph(MessagesState)
    builder.add_node(chat)
    builder.add_edge(START, "chat")
    graph = builder.compile(store=store)

    stream = await graph.astream_events(
        {"messages": [{"role": "user", "content": "I'm hungry"}]},
        version="v3",
    )
    async for message in stream.messages:
        async for token in message.text:
            print(token, end="", flush=True)
    

管理短期记忆

使用 短期记忆 启用后,长对话可能会超出 LLM 的上下文窗口。常见解决方案有:

  • * 修剪消息:移除前 N 条或后 N 条消息(在调用 LLM 之前)
  • * 删除消息 从 LangGraph 状态中永久删除
  • * 总结消息:总结历史中较早的消息并用摘要替换
  • * 管理检查点 存储和检索消息历史
  • * 自定义策略(例如消息过滤等)

这允许代理在不超过 LLM 上下文窗口的情况下跟踪对话。

修剪消息

大多数 LLM 都有最大支持的上下文窗口(以 token 为单位)。决定何时截断消息的一种方法是计算消息历史中的 token 数量,并在接近该限制时截断。如果你使用 LangChain,可以使用修剪消息工具并指定从列表中保留的 token 数量,以及用于处理边界的 strategy (例如,保留最后 max_tokens)来处理边界。

要修剪消息历史,请使用 trim_messages function:

from langchain_core.messages.utils import (  # [!code highlight]
    trim_messages,  # [!code highlight]
    count_tokens_approximately  # [!code highlight]
)  # [!code highlight]

def call_model(state: MessagesState):
    messages = trim_messages(  # [!code highlight]
        state["messages"],
        strategy="last",
        token_counter=count_tokens_approximately,
        max_tokens=128,
        start_on="human",
        end_on=("human", "tool"),
    )
    response = model.invoke(messages)
    return {"messages": [response]}

builder = StateGraph(MessagesState)
builder.add_node(call_model)
...

Full example: trim messages

  from langchain_core.messages.utils import (
      trim_messages,  # [!code highlight]
      count_tokens_approximately  # [!code highlight]
  )
  from langchain.chat_models import init_chat_model
  from langgraph.graph import StateGraph, START, MessagesState

  model = init_chat_model("claude-sonnet-4-6")
  summarization_model = model.bind(max_tokens=128)

  def call_model(state: MessagesState):
      messages = trim_messages(  # [!code highlight]
          state["messages"],
          strategy="last",
          token_counter=count_tokens_approximately,
          max_tokens=128,
          start_on="human",
          end_on=("human", "tool"),
      )
      response = model.invoke(messages)
      return {"messages": [response]}

  checkpointer = InMemorySaver()
  builder = StateGraph(MessagesState)
  builder.add_node(call_model)
  builder.add_edge(START, "call_model")
  graph = builder.compile(checkpointer=checkpointer)

  config = {"configurable": {"thread_id": "1"}}
  graph.invoke({"messages": "hi, my name is bob"}, config)
  graph.invoke({"messages": "write a short poem about cats"}, config)
  graph.invoke({"messages": "now do the same but for dogs"}, config)
  final_response = graph.invoke({"messages": "what's my name?"}, config)

  final_response["messages"][-1].pretty_print()
  ================================== Ai Message ==================================

  Your name is Bob, as you mentioned when you first introduced yourself.
  

删除消息

您可以从图状态中删除消息来管理消息历史。这在您想要删除特定消息或清除整个消息历史时非常有用。

要从图状态中删除消息,您可以使用 RemoveMessage。要使 RemoveMessage 正常工作,您需要使用带有 add_messages reducer的状态键,如 MessagesState.

要删除特定消息:

from langchain.messages import RemoveMessage  # [!code highlight]

def delete_messages(state):
    messages = state["messages"]
    if len(messages) > 2:
        # remove the earliest two messages
        return {"messages": [RemoveMessage(id=m.id) for m in messages[:2]]}  # [!code highlight]

要删除 **所有** messages:

from langgraph.graph.message import REMOVE_ALL_MESSAGES  # [!code highlight]

def delete_messages(state):
    return {"messages": [RemoveMessage(id=REMOVE_ALL_MESSAGES)]}  # [!code highlight]

Full example: delete messages

  from langchain.messages import RemoveMessage  # [!code highlight]

  def delete_messages(state):
      messages = state["messages"]
      if len(messages) > 2:
          # remove the earliest two messages
          return {"messages": [RemoveMessage(id=m.id) for m in messages[:2]]}  # [!code highlight]

  def call_model(state: MessagesState):
      response = model.invoke(state["messages"])
      return {"messages": response}

  builder = StateGraph(MessagesState)
  builder.add_sequence([call_model, delete_messages])
  builder.add_edge(START, "call_model")

  checkpointer = InMemorySaver()
  app = builder.compile(checkpointer=checkpointer)

  stream = app.stream_events(
      {"messages": [{"role": "user", "content": "hi! I'm bob"}]},
      config,
      version="v3"
  )
  for snapshot in stream.values:
      print([(message.type, message.content) for message in snapshot["messages"]])

  stream = app.stream_events(
      {"messages": [{"role": "user", "content": "what's my name?"}]},
      config,
      version="v3"
  )
  for snapshot in stream.values:
      print([(message.type, message.content) for message in snapshot["messages"]])
  [('human', "hi! I'm bob")]
  [('human', "hi! I'm bob"), ('ai', 'Hi Bob! How are you doing today? Is there anything I can help you with?')]
  [('human', "hi! I'm bob"), ('ai', 'Hi Bob! How are you doing today? Is there anything I can help you with?'), ('human', "what's my name?")]
  [('human', "hi! I'm bob"), ('ai', 'Hi Bob! How are you doing today? Is there anything I can help you with?'), ('human', "what's my name?"), ('ai', 'Your name is Bob.')]
  [('human', "what's my name?"), ('ai', 'Your name is Bob.')]
  

摘要消息

如上所示,修剪或删除消息的问题在于您可能会从消息队列的清理中丢失信息。因此,一些应用程序受益于使用聊天模型对消息历史进行摘要的更复杂方法。

!摘要

提示和编排逻辑可用于对消息历史进行摘要。例如,在 LangGraph 中,您可以扩展 MessagesState 以包含一个 summary key:

from langgraph.graph import MessagesState
class State(MessagesState):
    summary: str

然后,您可以使用任何现有摘要作为下一个摘要的上下文来生成聊天历史的摘要。此 summarize_conversation 节点可以在一定数量的消息累积在 messages 状态键中后调用。

def summarize_conversation(state: State):

    # First, we get any existing summary
    summary = state.get("summary", "")

    # Create our summarization prompt
    if summary:

        # A summary already exists
        summary_message = (
            f"This is a summary of the conversation to date: {summary}\n\n"
            "Extend the summary by taking into account the new messages above:"
        )

    else:
        summary_message = "Create a summary of the conversation above:"

    # Add prompt to our history
    messages = state["messages"] + [HumanMessage(content=summary_message)]
    response = model.invoke(messages)

    # Delete all but the 2 most recent messages
    delete_messages = [RemoveMessage(id=m.id) for m in state["messages"][:-2]]
    return {"summary": response.content, "messages": delete_messages}

Full example: summarize messages

  from typing import Any, TypedDict

  from langchain.chat_models import init_chat_model
  from langchain.messages import AnyMessage
  from langchain_core.messages.utils import count_tokens_approximately
  from langgraph.graph import StateGraph, START, MessagesState
  from langgraph.checkpoint.memory import InMemorySaver
  from langmem.short_term import SummarizationNode, RunningSummary  # [!code highlight]

  model = init_chat_model("claude-sonnet-4-6")
  summarization_model = model.bind(max_tokens=128)

  class State(MessagesState):
      context: dict[str, RunningSummary]  # [!code highlight]

  class LLMInputState(TypedDict):  # [!code highlight]
      summarized_messages: list[AnyMessage]
      context: dict[str, RunningSummary]

  summarization_node = SummarizationNode(  # [!code highlight]
      token_counter=count_tokens_approximately,
      model=summarization_model,
      max_tokens=256,
      max_tokens_before_summary=256,
      max_summary_tokens=128,
  )

  def call_model(state: LLMInputState):  # [!code highlight]
      response = model.invoke(state["summarized_messages"])
      return {"messages": [response]}

  checkpointer = InMemorySaver()
  builder = StateGraph(State)
  builder.add_node(call_model)
  builder.add_node("summarize", summarization_node)  # [!code highlight]
  builder.add_edge(START, "summarize")
  builder.add_edge("summarize", "call_model")
  graph = builder.compile(checkpointer=checkpointer)

  # Invoke the graph
  config = {"configurable": {"thread_id": "1"}}
  graph.invoke({"messages": "hi, my name is bob"}, config)
  graph.invoke({"messages": "write a short poem about cats"}, config)
  graph.invoke({"messages": "now do the same but for dogs"}, config)
  final_response = graph.invoke({"messages": "what's my name?"}, config)

  final_response["messages"][-1].pretty_print()
  print("\nSummary:", final_response["context"]["running_summary"].summary)
  1. 我们将在 context 字段中跟踪我们的运行摘要

(由 SummarizationNode).

  1. 定义仅用于过滤的私有状态

的输入 call_model node.

  1. 我们在这里传递一个私有输入状态,以隔离由摘要节点返回的消息
  ================================== Ai Message ==================================

  From our conversation, I can see that you introduced yourself as Bob. That's the name you shared with me when we began talking.

  Summary: In this conversation, I was introduced to Bob, who then asked me to write a poem about cats. I composed a poem titled "The Mystery of Cats" that captured cats' graceful movements, independent nature, and their special relationship with humans. Bob then requested a similar poem about dogs, so I wrote "The Joy of Dogs," which highlighted dogs' loyalty, enthusiasm, and loving companionship. Both poems were written in a similar style but emphasized the distinct characteristics that make each pet special.
  

管理检查点

您可以查看和删除由检查点存储的信息。

<a id="checkpoint"></a> #### 查看线程状态

Graph/Functional API

    config = {
        "configurable": {
            "thread_id": "1",  # [!code highlight]
            # optionally provide an ID for a specific checkpoint,
            # otherwise the latest checkpoint is shown
            # "checkpoint_id": "1f029ca3-1f5b-6704-8004-820c16b69a5a"  # [!code highlight]

        }
    }
    graph.get_state(config)  # [!code highlight]
    StateSnapshot(
        values={'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today?), HumanMessage(content="what's my name?"), AIMessage(content='Your name is Bob.')]}, next=(),
        config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1f5b-6704-8004-820c16b69a5a'}},
        metadata={
            'source': 'loop',
            'writes': {'call_model': {'messages': AIMessage(content='Your name is Bob.')}},
            'step': 4,
            'parents': {},
            'thread_id': '1'
        },
        created_at='2025-05-05T16:01:24.680462+00:00',
        parent_config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
        tasks=(),
        interrupts=()
    )
    

Checkpointer API

    config = {
        "configurable": {
            "thread_id": "1",  # [!code highlight]
            # optionally provide an ID for a specific checkpoint,
            # otherwise the latest checkpoint is shown
            # "checkpoint_id": "1f029ca3-1f5b-6704-8004-820c16b69a5a"  # [!code highlight]

        }
    }
    checkpointer.get_tuple(config)  # [!code highlight]
    CheckpointTuple(
        config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1f5b-6704-8004-820c16b69a5a'}},
        checkpoint={
            'v': 3,
            'ts': '2025-05-05T16:01:24.680462+00:00',
            'id': '1f029ca3-1f5b-6704-8004-820c16b69a5a',
            'channel_versions': {'__start__': '00000000000000000000000000000005.0.5290678567601859', 'messages': '00000000000000000000000000000006.0.3205149138784782', 'branch:to:call_model': '00000000000000000000000000000006.0.14611156755133758'}, 'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000004.0.5736472536395331'}, 'call_model': {'branch:to:call_model': '00000000000000000000000000000005.0.1410174088651449'}},
            'channel_values': {'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today?), HumanMessage(content="what's my name?"), AIMessage(content='Your name is Bob.')]},
        },
        metadata={
            'source': 'loop',
            'writes': {'call_model': {'messages': AIMessage(content='Your name is Bob.')}},
            'step': 4,
            'parents': {},
            'thread_id': '1'
        },
        parent_config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
        pending_writes=[]
    )
    

<a id="checkpoints"></a> #### 查看线程的历史记录

Graph/Functional API

    config = {
        "configurable": {
            "thread_id": "1"  # [!code highlight]
        }
    }
    list(graph.get_state_history(config))  # [!code highlight]
    [
        StateSnapshot(
            values={'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?'), HumanMessage(content="what's my name?"), AIMessage(content='Your name is Bob.')]},
            next=(),
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1f5b-6704-8004-820c16b69a5a'}},
            metadata={'source': 'loop', 'writes': {'call_model': {'messages': AIMessage(content='Your name is Bob.')}}, 'step': 4, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:24.680462+00:00',
            parent_config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
            tasks=(),
            interrupts=()
        ),
        StateSnapshot(
            values={'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?'), HumanMessage(content="what's my name?")]},
            next=('call_model',),
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
            metadata={'source': 'loop', 'writes': None, 'step': 3, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:23.863421+00:00',
            parent_config={...}
            tasks=(PregelTask(id='8ab4155e-6b15-b885-9ce5-bed69a2c305c', name='call_model', path=('__pregel_pull', 'call_model'), error=None, interrupts=(), state=None, result={'messages': AIMessage(content='Your name is Bob.')}),),
            interrupts=()
        ),
        StateSnapshot(
            values={'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')]},
            next=('__start__',),
            config={...},
            metadata={'source': 'input', 'writes': {'__start__': {'messages': [{'role': 'user', 'content': "what's my name?"}]}}, 'step': 2, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:23.863173+00:00',
            parent_config={...}
            tasks=(PregelTask(id='24ba39d6-6db1-4c9b-f4c5-682aeaf38dcd', name='__start__', path=('__pregel_pull', '__start__'), error=None, interrupts=(), state=None, result={'messages': [{'role': 'user', 'content': "what's my name?"}]}),),
            interrupts=()
        ),
        StateSnapshot(
            values={'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')]},
            next=(),
            config={...},
            metadata={'source': 'loop', 'writes': {'call_model': {'messages': AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')}}, 'step': 1, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:23.862295+00:00',
            parent_config={...}
            tasks=(),
            interrupts=()
        ),
        StateSnapshot(
            values={'messages': [HumanMessage(content="hi! I'm bob")]},
            next=('call_model',),
            config={...},
            metadata={'source': 'loop', 'writes': None, 'step': 0, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:22.278960+00:00',
            parent_config={...}
            tasks=(PregelTask(id='8cbd75e0-3720-b056-04f7-71ac805140a0', name='call_model', path=('__pregel_pull', 'call_model'), error=None, interrupts=(), state=None, result={'messages': AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')}),),
            interrupts=()
        ),
        StateSnapshot(
            values={'messages': []},
            next=('__start__',),
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-0870-6ce2-bfff-1f3f14c3e565'}},
            metadata={'source': 'input', 'writes': {'__start__': {'messages': [{'role': 'user', 'content': "hi! I'm bob"}]}}, 'step': -1, 'parents': {}, 'thread_id': '1'},
            created_at='2025-05-05T16:01:22.277497+00:00',
            parent_config=None,
            tasks=(PregelTask(id='d458367b-8265-812c-18e2-33001d199ce6', name='__start__', path=('__pregel_pull', '__start__'), error=None, interrupts=(), state=None, result={'messages': [{'role': 'user', 'content': "hi! I'm bob"}]}),),
            interrupts=()
        )
    ]
    

Checkpointer API

    config = {
        "configurable": {
            "thread_id": "1"  # [!code highlight]
        }
    }
    list(checkpointer.list(config))  # [!code highlight]
    [
        CheckpointTuple(
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1f5b-6704-8004-820c16b69a5a'}},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:24.680462+00:00',
                'id': '1f029ca3-1f5b-6704-8004-820c16b69a5a',
                'channel_versions': {'__start__': '00000000000000000000000000000005.0.5290678567601859', 'messages': '00000000000000000000000000000006.0.3205149138784782', 'branch:to:call_model': '00000000000000000000000000000006.0.14611156755133758'},
                'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000004.0.5736472536395331'}, 'call_model': {'branch:to:call_model': '00000000000000000000000000000005.0.1410174088651449'}},
                'channel_values': {'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?'), HumanMessage(content="what's my name?"), AIMessage(content='Your name is Bob.')]},
            },
            metadata={'source': 'loop', 'writes': {'call_model': {'messages': AIMessage(content='Your name is Bob.')}}, 'step': 4, 'parents': {}, 'thread_id': '1'},
            parent_config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
            pending_writes=[]
        ),
        CheckpointTuple(
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-1790-6b0a-8003-baf965b6a38f'}},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:23.863421+00:00',
                'id': '1f029ca3-1790-6b0a-8003-baf965b6a38f',
                'channel_versions': {'__start__': '00000000000000000000000000000005.0.5290678567601859', 'messages': '00000000000000000000000000000006.0.3205149138784782', 'branch:to:call_model': '00000000000000000000000000000006.0.14611156755133758'},
                'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000004.0.5736472536395331'}, 'call_model': {'branch:to:call_model': '00000000000000000000000000000005.0.1410174088651449'}},
                'channel_values': {'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?'), HumanMessage(content="what's my name?")], 'branch:to:call_model': None}
            },
            metadata={'source': 'loop', 'writes': None, 'step': 3, 'parents': {}, 'thread_id': '1'},
            parent_config={...},
            pending_writes=[('8ab4155e-6b15-b885-9ce5-bed69a2c305c', 'messages', AIMessage(content='Your name is Bob.'))]
        ),
        CheckpointTuple(
            config={...},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:23.863173+00:00',
                'id': '1f029ca3-1790-616e-8002-9e021694a0cd',
                'channel_versions': {'__start__': '00000000000000000000000000000004.0.5736472536395331', 'messages': '00000000000000000000000000000003.0.7056767754077798', 'branch:to:call_model': '00000000000000000000000000000003.0.22059023329132854'},
                'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000001.0.7040775356287469'}, 'call_model': {'branch:to:call_model': '00000000000000000000000000000002.0.9300422176788571'}},
                'channel_values': {'__start__': {'messages': [{'role': 'user', 'content': "what's my name?"}]}, 'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')]}
            },
            metadata={'source': 'input', 'writes': {'__start__': {'messages': [{'role': 'user', 'content': "what's my name?"}]}}, 'step': 2, 'parents': {}, 'thread_id': '1'},
            parent_config={...},
            pending_writes=[('24ba39d6-6db1-4c9b-f4c5-682aeaf38dcd', 'messages', [{'role': 'user', 'content': "what's my name?"}]), ('24ba39d6-6db1-4c9b-f4c5-682aeaf38dcd', 'branch:to:call_model', None)]
        ),
        CheckpointTuple(
            config={...},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:23.862295+00:00',
                'id': '1f029ca3-178d-6f54-8001-d7b180db0c89',
                'channel_versions': {'__start__': '00000000000000000000000000000002.0.18673090920108737', 'messages': '00000000000000000000000000000003.0.7056767754077798', 'branch:to:call_model': '00000000000000000000000000000003.0.22059023329132854'},
                'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000001.0.7040775356287469'}, 'call_model': {'branch:to:call_model': '00000000000000000000000000000002.0.9300422176788571'}},
                'channel_values': {'messages': [HumanMessage(content="hi! I'm bob"), AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')]}
            },
            metadata={'source': 'loop', 'writes': {'call_model': {'messages': AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?')}}, 'step': 1, 'parents': {}, 'thread_id': '1'},
            parent_config={...},
            pending_writes=[]
        ),
        CheckpointTuple(
            config={...},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:22.278960+00:00',
                'id': '1f029ca3-0874-6612-8000-339f2abc83b1',
                'channel_versions': {'__start__': '00000000000000000000000000000002.0.18673090920108737', 'messages': '00000000000000000000000000000002.0.30296526818059655', 'branch:to:call_model': '00000000000000000000000000000002.0.9300422176788571'},
                'versions_seen': {'__input__': {}, '__start__': {'__start__': '00000000000000000000000000000001.0.7040775356287469'}},
                'channel_values': {'messages': [HumanMessage(content="hi! I'm bob")], 'branch:to:call_model': None}
            },
            metadata={'source': 'loop', 'writes': None, 'step': 0, 'parents': {}, 'thread_id': '1'},
            parent_config={...},
            pending_writes=[('8cbd75e0-3720-b056-04f7-71ac805140a0', 'messages', AIMessage(content='Hi Bob! How are you doing today? Is there anything I can help you with?'))]
        ),
        CheckpointTuple(
            config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '1f029ca3-0870-6ce2-bfff-1f3f14c3e565'}},
            checkpoint={
                'v': 3,
                'ts': '2025-05-05T16:01:22.277497+00:00',
                'id': '1f029ca3-0870-6ce2-bfff-1f3f14c3e565',
                'channel_versions': {'__start__': '00000000000000000000000000000001.0.7040775356287469'},
                'versions_seen': {'__input__': {}},
                'channel_values': {'__start__': {'messages': [{'role': 'user', 'content': "hi! I'm bob"}]}}
            },
            metadata={'source': 'input', 'writes': {'__start__': {'messages': [{'role': 'user', 'content': "hi! I'm bob"}]}}, 'step': -1, 'parents': {}, 'thread_id': '1'},
            parent_config=None,
            pending_writes=[('d458367b-8265-812c-18e2-33001d199ce6', 'messages', [{'role': 'user', 'content': "hi! I'm bob"}]), ('d458367b-8265-812c-18e2-33001d199ce6', 'branch:to:call_model', None)]
        )
    ]
    

删除线程的所有检查点

thread_id = "1"
checkpointer.delete_thread(thread_id)

数据库管理

If you are using any database-backed persistence implementation (such as Postgres, Redis, or Oracle) to store short and/or long-term memory, you will need to run migrations to set up the required schema before you can use it with your database.

按照惯例,大多数特定于数据库的库会定义一个 setup() 检查点或存储实例上运行所需迁移的方法。但是,您应该查看您的特定实现BaseCheckpointSaver] or @[BaseStore以确认确切的方法名称和用法。

我们建议将迁移作为专门的部署步骤运行,或者您可以确保它们在服务器启动时运行。