There is no usable working Builder for a FunctionCallback

[fedecompa]

Bug description
The class DefaultFunctionCallbackBuilder has a field private String inputTypeSchema, but there is no .build() method to costruct an instance of a FunctionCallback defined at runtime. The class FunctionInvokingFunctionCallback has not public constructor.

Environment
Spring AI version: 1.0.0-SNAPSHOT
Java version: 17

Expected behavior
I need a public usable Builder where I can set the name, the description and the JSON schema in string format (and not necessarily a Class) and returning an instance of FunctionCallback.

	DefaultFunctionCallbackBuilder defaultFunctionCallbackBuilder = new DefaultFunctionCallbackBuilder();
	FunctionCallback.Builder builder = defaultFunctionCallbackBuilder
			.description(description).inputTypeSchema(parameters)
			.schemaType(FunctionCallbackContext.SchemaType.JSON_SCHEMA);
	FunctionCallback functionCallback = builder.build();    // MISSING !
	ChatOptions promptOptions = AzureOpenAiChatOptions.builder()
			.withResponseFormat(AzureOpenAiResponseFormat.JSON)
			.withFunctionCallbacks(List.of(functionCallback)).build();

[markpollack]

Some changes were made to the builder since we got to triage this issue.

You can use this style of the builder to achieve what you want now.

	FunctionCallback.builder().function("functionName", input -> "output").inputTypeSchema("my custom schema").description("my description").schemaType(FunctionCallback.SchemaType.JSON_SCHEMA);
	

Let us know if this solves your issue.

Thanks

[ilayaperumalg]

Closing this as the support around FunctionCallback and the generic Tool support is being addressed here