AttributeError: '_GeneratorContextManager' object has no attribute 'get_next_version'

[smanna123]

when i am trying to langgraph customer support example (https://langchain-ai.github.io/langgraph/tutorials/customer-support/customer-support/) , it is facing below error---

Traceback (most recent call last):
File "/home/broadifi/Desktop/ofc_project/lang_graph_bot/agentic_bot.py", line 406, in
for event in events:
File "/home/broadifi/Desktop/ofc_project/lang_graph_bot/venv/lib/python3.10/site-packages/langgraph/pregel/init.py", line 1190, in stream
with SyncPregelLoop(
File "/home/broadifi/Desktop/ofc_project/lang_graph_bot/venv/lib/python3.10/site-packages/langgraph/pregel/loop.py", line 562, in init
self.checkpointer_get_next_version = checkpointer.get_next_version
AttributeError: '_GeneratorContextManager' object has no attribute 'get_next_version'

with the older version it was working fine but after upgradation it is facing above error

[vbarda]

@smanna123 it looks like you're using SqliteSaver.from_conn_string() as a checkpointer, but it actually is a context manager. the right way to use it is

with SqliteSaver.from_conn_string(...) as checkpointer:
    app = graph.compile(checkpointer=checkpointer)
    app.invoke(...)

hope this helps!

[TonySimonovsky]

This code(from the topic) is actually from your DeepLearning course

[vbarda]

Yes, unfortunately the course was published before we introduce this change. Will look into whether we can update the materials!

[sameeragorijelli]

In Lesson6:Essay Writer of AI Agents in LangGraph also getting similar error.

while executing the below code:

thread = {"configurable": {"thread_id": "1"}}
for s in graph.stream({
'task': "what is the difference between langchain and langsmith",
"max_revisions": 2,
"revision_number": 1,
}, thread):
print(s)

 I am getting AttributeError: '_GeneratorContextManager' object has no attribute 'get_next_version'.

The error is as follows:

 ---------------------------------------------------------------------------

AttributeError Traceback (most recent call last)
Cell In[52], line 2
1 thread = {"configurable": {"thread_id": "1"}}
----> 2 for s in graph.stream({
3 'task': "what is the difference between langchain and langsmith",
4 "max_revisions": 2,
5 "revision_number": 1,
6 }, thread):
7 print(s)

File /opt/conda/lib/python3.11/site-packages/langgraph/pregel/init.py:1284, in Pregel.stream(self, input, config, stream_mode, output_keys, interrupt_before, interrupt_after, debug, subgraphs)
1280 if "custom" in stream_modes:
1281 config[CONF][CONFIG_KEY_STREAM_WRITER] = lambda c: stream.put(
1282 ((), "custom", c)
1283 )
-> 1284 with SyncPregelLoop(
1285 input,
1286 stream=StreamProtocol(stream.put, stream_modes),
1287 config=config,
1288 store=store,
1289 checkpointer=checkpointer,
1290 nodes=self.nodes,
1291 specs=self.channels,
1292 output_keys=output_keys,
1293 stream_keys=self.stream_channels_asis,
1294 debug=debug,
1295 ) as loop:
1296 # create runner
1297 runner = PregelRunner(
1298 submit=loop.submit,
1299 put_writes=loop.put_writes,
1300 node_finished=config[CONF].get(CONFIG_KEY_NODE_FINISHED),
1301 )
1302 # enable subgraph streaming

File /opt/conda/lib/python3.11/site-packages/langgraph/pregel/loop.py:654, in SyncPregelLoop.init(self, input, stream, config, store, checkpointer, nodes, specs, output_keys, stream_keys, check_subgraphs, debug)
652 self.stack = ExitStack()
653 if checkpointer:
--> 654 self.checkpointer_get_next_version = checkpointer.get_next_version
655 self.checkpointer_put_writes = checkpointer.put_writes
656 else:

AttributeError: '_GeneratorContextManager' object has no attribute 'get_next_version'

Can you suggest any solution.

[githubramu]

from langgraph.checkpoint.memory import MemorySaver
memory = MemorySaver()

This fixed the issue.

[vbarda]

This is not a fix to the above issue though, the correct solution for sqlite checkpointer is using it as a context manager as in the selected answer

[Saifullah3711]

This really helped in memory