AnthropicChatGenerator StreamingChunk "meta" is empty

[wursterje]

I am looking for some meta information, similar to the OpenAIChatGenerator, to capture the stop event. Unfortunately, the meta field for the AnthropicChatGenerator is empty.

I added some print statements for debugging to AnthropicChatGenerator (line 221 and 227):

  # if streaming is enabled, the response is a Stream[MessageStreamEvent]
        if isinstance(response, Stream):
            chunks: List[StreamingChunk] = []
            stream_event, delta, start_event = None, None, None
            for stream_event in response:
                print(stream_event)
                if isinstance(stream_event, MessageStartEvent):
                    # capture start message to count input tokens
                    start_event = stream_event
                if isinstance(stream_event, ContentBlockDeltaEvent):
                    chunk_delta: StreamingChunk = self._build_chunk(stream_event.delta)
                    print(chunk_delta)
                    chunks.append(chunk_delta)

And here is the output where you can see that the meta field is empty:

RawContentBlockDeltaEvent(delta=TextDelta(text='d of test', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content='d of test', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=" you're", type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=" you're", meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=' referring to? Once', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=' referring to? Once', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=' you give', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=' you give', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=' me more context or', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=' me more context or', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=' a specific question, I', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=' a specific question, I', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text="'ll do my best to", type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content="'ll do my best to", meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text=' assist you', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content=' assist you', meta={})
RawContentBlockDeltaEvent(delta=TextDelta(text='.', type='text_delta'), index=0, type='content_block_delta')
StreamingChunk(content='.', meta={})
RawContentBlockStopEvent(index=0, type='content_block_stop')
RawMessageDeltaEvent(delta=Delta(stop_reason='end_turn', stop_sequence=None), type='message_delta', usage=MessageDeltaUsage(output_tokens=93))
RawMessageStopEvent(type='message_stop')

Version: anthropic-haystack 1.1.0