Revert "anthropic: stream token usage" (#22624)

Reverts langchain-ai/langchain#20180

libs/partners/anthropic/langchain_anthropic/chat_models.py

@@ -43,7 +43,6 @@ from langchain_core.messages import (
     ToolCall,
     ToolMessage,
 )
-from langchain_core.messages.ai import UsageMetadata
 from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult
 from langchain_core.pydantic_v1 import BaseModel, Field, SecretStr, root_validator
 from langchain_core.runnables import (
@@ -654,20 +653,14 @@ class ChatAnthropic(BaseChatModel):
                 message_chunk = AIMessageChunk(
                     content=message.content,
                     tool_call_chunks=tool_call_chunks,  # type: ignore[arg-type]
-                    usage_metadata=message.usage_metadata,
                 )
                 yield ChatGenerationChunk(message=message_chunk)
             else:
                 yield cast(ChatGenerationChunk, result.generations[0])
             return
-        full_generation_info: dict = {}
         with self._client.messages.stream(**params) as stream:
             for text in stream.text_stream:
-                chunk, full_generation_info = _make_chat_generation_chunk(
-                    text,
-                    stream.current_message_snapshot.model_dump(),
-                    full_generation_info,
-                )
+                chunk = ChatGenerationChunk(message=AIMessageChunk(content=text))
                 if run_manager:
                     run_manager.on_llm_new_token(text, chunk=chunk)
                 yield chunk
@@ -699,20 +692,14 @@ class ChatAnthropic(BaseChatModel):
                 message_chunk = AIMessageChunk(
                     content=message.content,
                     tool_call_chunks=tool_call_chunks,  # type: ignore[arg-type]
-                    usage_metadata=message.usage_metadata,
                 )
                 yield ChatGenerationChunk(message=message_chunk)
             else:
                 yield cast(ChatGenerationChunk, result.generations[0])
             return
-        full_generation_info: dict = {}
         async with self._async_client.messages.stream(**params) as stream:
             async for text in stream.text_stream:
-                chunk, full_generation_info = _make_chat_generation_chunk(
-                    text,
-                    stream.current_message_snapshot.model_dump(),
-                    full_generation_info,
-                )
+                chunk = ChatGenerationChunk(message=AIMessageChunk(content=text))
                 if run_manager:
                     await run_manager.on_llm_new_token(text, chunk=chunk)
                 yield chunk
@@ -1077,59 +1064,6 @@ def _lc_tool_calls_to_anthropic_tool_use_blocks(
     return blocks
 
 
-def _make_chat_generation_chunk(
-    text: str, message_dump: dict, full_generation_info: dict
-) -> Tuple[ChatGenerationChunk, dict]:
-    """Collect metadata and make ChatGenerationChunk.
-
-    Args:
-        text: text of the message chunk
-        message_dump: dict with metadata of the message chunk
-        full_generation_info: dict collecting metadata for full stream
-
-    Returns:
-        Tuple with ChatGenerationChunk and updated full_generation_info
-    """
-    generation_info = {}
-    usage_metadata: Optional[UsageMetadata] = None
-    for k, v in message_dump.items():
-        if k in ("content", "role", "type") or (
-            k in full_generation_info and k not in ("usage", "stop_reason")
-        ):
-            continue
-        elif k == "usage":
-            input_tokens = v.get("input_tokens", 0)
-            output_tokens = v.get("output_tokens", 0)
-            if "usage" not in full_generation_info:
-                full_generation_info[k] = v
-                usage_metadata = UsageMetadata(
-                    input_tokens=input_tokens,
-                    output_tokens=output_tokens,
-                    total_tokens=input_tokens + output_tokens,
-                )
-            else:
-                seen_input_tokens = full_generation_info[k].get("input_tokens", 0)
-                # Anthropic returns the same input token count for each message in a
-                # stream. To avoid double counting, we only count the input tokens
-                # once. After that, we set the input tokens to zero.
-                new_input_tokens = 0 if seen_input_tokens else input_tokens
-                usage_metadata = UsageMetadata(
-                    input_tokens=new_input_tokens,
-                    output_tokens=output_tokens,
-                    total_tokens=new_input_tokens + output_tokens,
-                )
-        else:
-            full_generation_info[k] = v
-            generation_info[k] = v
-    return (
-        ChatGenerationChunk(
-            message=AIMessageChunk(content=text, usage_metadata=usage_metadata),
-            generation_info=generation_info,
-        ),
-        full_generation_info,
-    )
-
-
 @deprecated(since="0.1.0", removal="0.3.0", alternative="ChatAnthropic")
 class ChatAnthropicMessages(ChatAnthropic):
     pass