def add_generation(self, langfuse_generation_data: LangfuseGeneration | None = None):

        data = filter_none_values(langfuse_generation_data.model_dump()) if langfuse_generation_data else {}

        try:

            usage_data = data.pop("usage", None)

            usage = None

            if usage_data:

                usage = Usage(

                    input=usage_data.get("input", 0) or 0,

                    output=usage_data.get("output", 0) or 0,

                    total=usage_data.get("total", 0) or 0,

                    unit=usage_data.get("unit"),

                    input_cost=usage_data.get("inputCost"),

                    output_cost=usage_data.get("outputCost"),

                    total_cost=usage_data.get("totalCost"),

                )



            # Langfuse v4 requires observation body.id; auto-assign if missing

            if not data.get("id"):

                data["id"] = str(uuid.uuid4())

            body = CreateGenerationBody(

                id=data.get("id"),

                trace_id=data.get("trace_id"),

                name=data.get("name"),

                start_time=data.get("start_time"),

                end_time=data.get("end_time"),

                model=data.get("model"),

                model_parameters=data.get("model_parameters"),

                input=data.get("input"),

                output=data.get("output"),

                usage=usage,

                metadata=data.get("metadata"),

                level=data.get("level"),

                status_message=data.get("status_message"),

                parent_observation_id=data.get("parent_observation_id"),

                version=data.get("version"),

                completion_start_time=data.get("completion_start_time"),

            )

            event = IngestionEvent_GenerationCreate(

                body=body,

                id=self._make_event_id(),

                timestamp=self._now_iso(),

            )

            self.langfuse_client.api.ingestion.batch(batch=[event])

            logger.debug("LangFuse Generation created successfully")

        except Exception as e:

            raise ValueError(f"LangFuse Failed to create generation: {str(e)}")