Error while checkpoint - Timestamps must be monotonically increasing

[flavioaltimari]

I'm getting this error aways when I have checkpoint in model: Timestamps must be monotonically increasing
I tried also the langgraph tutorials and got the same error.

Sometimes it work, but mostly times don't.

I tried with checkpoint on memory, and on sqlite file.
I tried to change the [C:\Python\lib\site-packages\langgraph\channels\base.py:118] utc

none of that worked.

What could be?

Tutorial:
https://langchain-ai.github.io/langgraph/tutorials/customer-support/customer-support/

The full error:

`AssertionError Traceback (most recent call last)
Cell In[83], line 5
1 events = part_1_graph.stream(
2 {"messages": ("user", "Hi there, what time is my flight?")}, config, stream_mode="values"
3 )
4 print (events)
----> 5 for event in events:
6 _print_event(event, _printed)

File C:\Python\lib\site-packages\langgraph\pregel_init_.py:674, in Pregel.stream(self, input, config, stream_mode, output_keys, input_keys, interrupt_before, interrupt_after, debug)
672 # save input checkpoint
673 if self.checkpointer is not None:
--> 674 checkpoint = create_checkpoint(checkpoint, channels)
675 bg.append(
676 executor.submit(
677 self.checkpointer.put,
(...)
681 )
682 )
683 checkpoint_config = {
684 "configurable": {
685 "thread_id": checkpoint_config["configurable"][
(...)
689 }
690 }

File C:\Python\lib\site-packages\langgraph\channels\base.py:118, in create_checkpoint(checkpoint, channels)
116 #ts = datetime.now(timezone.utc).isoformat()
117 ts = datetime.now().isoformat()
--> 118 assert ts > checkpoint["ts"], "Timestamps must be monotonically increasing"
119 values: dict[str, Any] = {}
120 for k, v in channels.items():

AssertionError: Timestamps must be monotonically increasing`

[jktoh]

Downgrading to 0.0.44 resolved my issue

[AtmehEsraa]

did you try it with llama3 or any open source model ?

[jktoh]

I was using ChatOpenAI and langgraph 0.0.48 which got me a similar error as above
Using ChatOpenAI and langgraph 0.0.44 worked for me

[nfcampos]

Fixed in #453

[flavioaltimari]

How I solve it:

just put # on line 117 of base.py file
C:\Python\lib\site-packages\langgraph\channels\

File C:\Python\lib\site-packages\langgraph\channels\base.py:118, in create_checkpoint(checkpoint, channels)
116 ts = datetime.now(timezone.utc).isoformat()
117 #assert ts > checkpoint["ts"], "Timestamps must be monotonically increasing"
118 values: dict[str, Any] = {}
119 for k, v in channels.items():