Error with arbitrary_types_allowed

[kientv]

Please help to solve this problem:

from langserve import add_routes
from langserve.pydantic_v1 import BaseModel

pip freeze | grep -E "langchain|langserve|pydantic"
langchain==0.2.16
langchain-community==0.2.17
langchain-core==0.2.41
langchain-google-genai==1.0.10
langchain-google-vertexai==1.0.10
langchain-openai==0.1.25
langchain-text-splitters==0.2.4
langserve==0.2.3
openapi-pydantic==0.4.1
openapi-schema-pydantic==1.2.4
pydantic==1.10.9
pydantic_core==2.23.4

lib/python3.11/site-packages/pydantic/v1/validators.py", line 765, in find_validators
    raise RuntimeError(f'no validator found for {type_}, see `arbitrary_types_allowed` in Config')
RuntimeError: no validator found for <class 'langchain_core.messages.base.BaseMessage'>, see `arbitrary_types_allowed` in Config

[eyurtsev]

Could you include a minimal reproducible example?

arbitrary_types_allowed is a pydantic error indicating that some code is attempting to assign attributes that are arbitrary classes (or at least no a pydantic model or a python primitive) to a pydantic base model.

Also consider upgrading to langserve 0.3.x and moving away from the langserve.pydantic_v1 compatibility bridge

[kientv]

Migrated to 0.3.0, thanks :)