Gemini response format Plain-Text (Seems not permitted)

[SimonSuewerUHH]

Hello everyone,
Happy New Year first of all, I hope you've had a good start to the new year.

Is it possible that GeminiChatLanguageModel does not currently allow direct return from the string, but only within a json?
See:
https://github.com/quarkiverse/quarkus-langchain4j/blob/main/model-providers/google/gemini/gemini-common/runtime/src/main/java/io/quarkiverse/langchain4j/gemini/common/GeminiChatLanguageModel.java

When the chat function is called and the response type is text, the JSON schema is deliberately and correctly null.
However, this currently results in an NPE

I also set .responseFormat(ResponseFormat.TEXT)
Also i use the chatLanguageModelSupplier functionality

This is caused by:
public static Schema fromJsonSchemaToSchema(JsonSchema jsonSchema) { var result = fromJsonSchemaToSchema(jsonSchema.rootElement()); if ((result == null) || result.isEffectiveEmptyObject()) { return null; } return result; }

Is there any solution here, or is the answer that all responses must be JSON, even if the object only has a single string?

Thank you for your time.
Best regards
Simon

[geoand]

Thanks for reporting!

I can't say I understand the issue completely, but if you have a reproducer, that would help a lot.
Moreover, if you have a fix in mind, we'd be happy to accept it

[SimonSuewerUHH]

#2049

Thanks for the quick reply.
To clarify my problem again, I have an interface like “@SystemMessage(”“”..... “”“) @Usermessage(”“” QUESTION: {question} “‘’) String answer(String question);” Since this does not have a schema, an NPE occurred in the above method.
I have created a PR.
Since this is my first PR in this project, I would appreciate any feedback.

Thanks for your quick reply, have a nice day.

As mentioned in the PR, there is a quick fix for me if I set the response format to zero as described in the PR, i dont get the NPE

Cheers