OpenAI missing JSON properties with streaming

[GregoireDaure]

Describe the bug

Hi,

We are facing problems with OpenAiChatModel and streaming. We are getting errors about missing json properties i.e. finish_reason with a custom OpenAi endpoint.

BTW, we have no problem when streaming is off.

Steps to reproduce the bug

Create an OpenAiChatModel
Set streaming to true
Call GenerateAsync
An exception is raised for missing json properties

Expected behavior

Properties should not be required I guess.

Screenshots

NuGet package version

LangChain.Providers.OpenAI => 0.17.1-dev.45
LangChain.Core => 0.17.1-dev.51

Additional context

Is there any reason to not use the official OpenAI sdk instead of the AutoSDK generated version ?

[GregoireDaure]

Closing this as it appears to more be a bug on the side of our custom OpenAI endpoint not returning all the required properties. finish_reason is tagged as required in the OpenAPI spec