remove run id from hot path

libs/core/langchain_core/agents.py

@@ -69,7 +69,7 @@ class AgentAction(Serializable):
             tool_input: The input to pass in to the Tool.
             log: Additional information to log about the action.
         """
-        super().__init__(tool=tool, tool_input=tool_input, log=log, **kwargs)
+        super().__init__(tool=tool, tool_input=tool_input, log=log, **kwargs)  # type: ignore[call-arg]
 
     @classmethod
     def is_lc_serializable(cls) -> bool:
@@ -149,7 +149,7 @@ class AgentFinish(Serializable):
 
     def __init__(self, return_values: dict, log: str, **kwargs: Any):
         """Override init to support instantiation by position for backward compat."""
-        super().__init__(return_values=return_values, log=log, **kwargs)
+        super().__init__(return_values=return_values, log=log, **kwargs)  # type: ignore[call-arg]
 
     @classmethod
     def is_lc_serializable(cls) -> bool:

libs/core/langchain_core/callbacks/manager.py

@@ -520,6 +520,8 @@ class RunManager(BaseRunManager):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_text",
@@ -542,6 +544,8 @@ class RunManager(BaseRunManager):
             retry_state (RetryCallState): The retry state.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_retry",
@@ -601,6 +605,8 @@ class AsyncRunManager(BaseRunManager, ABC):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_text",
@@ -623,6 +629,8 @@ class AsyncRunManager(BaseRunManager, ABC):
             retry_state (RetryCallState): The retry state.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_retry",
@@ -675,6 +683,8 @@ class CallbackManagerForLLMRun(RunManager, LLMManagerMixin):
                 The chunk. Defaults to None.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_llm_new_token",
@@ -694,6 +704,8 @@ class CallbackManagerForLLMRun(RunManager, LLMManagerMixin):
             response (LLMResult): The LLM result.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_llm_end",
@@ -718,6 +730,8 @@ class CallbackManagerForLLMRun(RunManager, LLMManagerMixin):
                 - response (LLMResult): The response which was generated before
                     the error occurred.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_llm_error",
@@ -750,7 +764,6 @@ class AsyncCallbackManagerForLLMRun(AsyncRunManager, LLMManagerMixin):
             inheritable_metadata=self.inheritable_metadata,
         )
 
-    @shielded
     async def on_llm_new_token(
         self,
         token: str,
@@ -766,6 +779,8 @@ class AsyncCallbackManagerForLLMRun(AsyncRunManager, LLMManagerMixin):
                 The chunk. Defaults to None.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_llm_new_token",
@@ -786,6 +801,8 @@ class AsyncCallbackManagerForLLMRun(AsyncRunManager, LLMManagerMixin):
             response (LLMResult): The LLM result.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_llm_end",
@@ -814,6 +831,8 @@ class AsyncCallbackManagerForLLMRun(AsyncRunManager, LLMManagerMixin):
 
 
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_llm_error",
@@ -836,6 +855,8 @@ class CallbackManagerForChainRun(ParentRunManager, ChainManagerMixin):
             outputs (Union[dict[str, Any], Any]): The outputs of the chain.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_chain_end",
@@ -858,6 +879,8 @@ class CallbackManagerForChainRun(ParentRunManager, ChainManagerMixin):
             error (Exception or KeyboardInterrupt): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_chain_error",
@@ -879,6 +902,8 @@ class CallbackManagerForChainRun(ParentRunManager, ChainManagerMixin):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_agent_action",
@@ -900,6 +925,8 @@ class CallbackManagerForChainRun(ParentRunManager, ChainManagerMixin):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_agent_finish",
@@ -942,6 +969,8 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
             outputs (Union[dict[str, Any], Any]): The outputs of the chain.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_chain_end",
@@ -965,6 +994,8 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
             error (Exception or KeyboardInterrupt): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_chain_error",
@@ -976,7 +1007,6 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
             **kwargs,
         )
 
-    @shielded
     async def on_agent_action(self, action: AgentAction, **kwargs: Any) -> Any:
         """Run when agent action is received.
 
@@ -987,6 +1017,8 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_agent_action",
@@ -998,7 +1030,6 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
             **kwargs,
         )
 
-    @shielded
     async def on_agent_finish(self, finish: AgentFinish, **kwargs: Any) -> Any:
         """Run when agent finish is received.
 
@@ -1009,6 +1040,8 @@ class AsyncCallbackManagerForChainRun(AsyncParentRunManager, ChainManagerMixin):
         Returns:
             Any: The result of the callback.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_agent_finish",
@@ -1035,6 +1068,8 @@ class CallbackManagerForToolRun(ParentRunManager, ToolManagerMixin):
             output (Any): The output of the tool.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_tool_end",
@@ -1057,6 +1092,8 @@ class CallbackManagerForToolRun(ParentRunManager, ToolManagerMixin):
             error (Exception or KeyboardInterrupt): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_tool_error",
@@ -1089,7 +1126,6 @@ class AsyncCallbackManagerForToolRun(AsyncParentRunManager, ToolManagerMixin):
             inheritable_metadata=self.inheritable_metadata,
         )
 
-    @shielded
     async def on_tool_end(self, output: Any, **kwargs: Any) -> None:
         """Async run when the tool ends running.
 
@@ -1097,6 +1133,8 @@ class AsyncCallbackManagerForToolRun(AsyncParentRunManager, ToolManagerMixin):
             output (Any): The output of the tool.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_tool_end",
@@ -1108,7 +1146,6 @@ class AsyncCallbackManagerForToolRun(AsyncParentRunManager, ToolManagerMixin):
             **kwargs,
         )
 
-    @shielded
     async def on_tool_error(
         self,
         error: BaseException,
@@ -1120,6 +1157,8 @@ class AsyncCallbackManagerForToolRun(AsyncParentRunManager, ToolManagerMixin):
             error (Exception or KeyboardInterrupt): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_tool_error",
@@ -1146,6 +1185,8 @@ class CallbackManagerForRetrieverRun(ParentRunManager, RetrieverManagerMixin):
             documents (Sequence[Document]): The retrieved documents.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_retriever_end",
@@ -1168,6 +1209,8 @@ class CallbackManagerForRetrieverRun(ParentRunManager, RetrieverManagerMixin):
             error (BaseException): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         handle_event(
             self.handlers,
             "on_retriever_error",
@@ -1213,6 +1256,8 @@ class AsyncCallbackManagerForRetrieverRun(
             documents (Sequence[Document]): The retrieved documents.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_retriever_end",
@@ -1236,6 +1281,8 @@ class AsyncCallbackManagerForRetrieverRun(
             error (BaseException): The error.
             **kwargs (Any): Additional keyword arguments.
         """
+        if not self.handlers:
+            return
         await ahandle_event(
             self.handlers,
             "on_retriever_error",
@@ -1521,6 +1568,8 @@ class CallbackManager(BaseCallbackManager):
 
         .. versionadded:: 0.2.14
         """
+        if not self.handlers:
+            return
         if kwargs:
             msg = (
                 "The dispatcher API does not accept additional keyword arguments."
@@ -1998,6 +2047,8 @@ class AsyncCallbackManager(BaseCallbackManager):
 
         .. versionadded:: 0.2.14
         """
+        if not self.handlers:
+            return
         if run_id is None:
             run_id = uuid.uuid4()
 

libs/core/langchain_core/language_models/chat_models.py

@@ -66,6 +66,7 @@ from langchain_core.outputs import (
     LLMResult,
     RunInfo,
 )
+from langchain_core.outputs.chat_generation import merge_chat_generation_chunks
 from langchain_core.prompt_values import ChatPromptValue, PromptValue, StringPromptValue
 from langchain_core.rate_limiters import BaseRateLimiter
 from langchain_core.runnables import RunnableMap, RunnablePassthrough
@@ -485,34 +486,41 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
                 run_id=config.pop("run_id", None),
                 batch_size=1,
             )
-            generation: Optional[ChatGenerationChunk] = None
+
+            chunks: list[ChatGenerationChunk] = []
 
             if self.rate_limiter:
                 self.rate_limiter.acquire(blocking=True)
 
             try:
                 input_messages = _normalize_messages(messages)
+                run_id = "-".join((_LC_ID_PREFIX, str(run_manager.run_id)))
                 for chunk in self._stream(input_messages, stop=stop, **kwargs):
                     if chunk.message.id is None:
-                        chunk.message.id = f"{_LC_ID_PREFIX}-{run_manager.run_id}"
+                        chunk.message.id = run_id
                     chunk.message.response_metadata = _gen_info_and_msg_metadata(chunk)
                     run_manager.on_llm_new_token(
                         cast("str", chunk.message.content), chunk=chunk
                     )
+                    chunks.append(chunk)
                     yield chunk.message
-                    if generation is None:
-                        generation = chunk
-                    else:
-                        generation += chunk
             except BaseException as e:
                 generations_with_error_metadata = _generate_response_from_error(e)
-                if generation:
-                    generations = [[generation], generations_with_error_metadata]
+                chat_generation_chunk = merge_chat_generation_chunks(chunks)
+                if chat_generation_chunk:
+                    generations = [
+                        [chat_generation_chunk],
+                        generations_with_error_metadata,
+                    ]
                 else:
                     generations = [generations_with_error_metadata]
-                run_manager.on_llm_error(e, response=LLMResult(generations=generations))  # type: ignore[arg-type]
+                run_manager.on_llm_error(
+                    e,
+                    response=LLMResult(generations=generations),  # type: ignore[arg-type]
+                )
                 raise
 
+            generation = merge_chat_generation_chunks(chunks)
             if generation is None:
                 err = ValueError("No generation chunks were returned")
                 run_manager.on_llm_error(err, response=LLMResult(generations=[]))
@@ -575,29 +583,29 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
         if self.rate_limiter:
             await self.rate_limiter.aacquire(blocking=True)
 
-        generation: Optional[ChatGenerationChunk] = None
+        chunks: list[ChatGenerationChunk] = []
+
         try:
             input_messages = _normalize_messages(messages)
+            run_id = "-".join((_LC_ID_PREFIX, str(run_manager.run_id)))
             async for chunk in self._astream(
                 input_messages,
                 stop=stop,
                 **kwargs,
             ):
                 if chunk.message.id is None:
-                    chunk.message.id = f"{_LC_ID_PREFIX}-{run_manager.run_id}"
+                    chunk.message.id = run_id
                 chunk.message.response_metadata = _gen_info_and_msg_metadata(chunk)
                 await run_manager.on_llm_new_token(
                     cast("str", chunk.message.content), chunk=chunk
                 )
+                chunks.append(chunk)
                 yield chunk.message
-                if generation is None:
-                    generation = chunk
-                else:
-                    generation += chunk
         except BaseException as e:
             generations_with_error_metadata = _generate_response_from_error(e)
-            if generation:
-                generations = [[generation], generations_with_error_metadata]
+            chat_generation_chunk = merge_chat_generation_chunks(chunks)
+            if chat_generation_chunk:
+                generations = [[chat_generation_chunk], generations_with_error_metadata]
             else:
                 generations = [generations_with_error_metadata]
             await run_manager.on_llm_error(
@@ -606,7 +614,8 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
             )
             raise
 
-        if generation is None:
+        generation = merge_chat_generation_chunks(chunks)
+        if not generation:
             err = ValueError("No generation chunks were returned")
             await run_manager.on_llm_error(err, response=LLMResult(generations=[]))
             raise err

libs/core/langchain_core/load/serializable.py

@@ -124,11 +124,6 @@ class Serializable(BaseModel, ABC):
         as part of the serialized representation.
     """
 
-    # Remove default BaseModel init docstring.
-    def __init__(self, *args: Any, **kwargs: Any) -> None:
-        """"""  # noqa: D419
-        super().__init__(*args, **kwargs)
-
     @classmethod
     def is_lc_serializable(cls) -> bool:
         """Is this class serializable?

libs/core/langchain_core/messages/base.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING, Any, Optional, Union, cast
 
-from pydantic import ConfigDict, Field, field_validator
+from pydantic import ConfigDict, Field
 
 from langchain_core.load.serializable import Serializable
 from langchain_core.utils import get_bolded_text
@@ -52,7 +52,7 @@ class BaseMessage(Serializable):
     model implementation.
     """
 
-    id: Optional[str] = None
+    id: Optional[str] = Field(default=None, coerce_numbers_to_str=True)
     """An optional unique identifier for the message. This should ideally be
     provided by the provider/model which created the message."""
 
@@ -60,13 +60,6 @@ class BaseMessage(Serializable):
         extra="allow",
     )
 
-    @field_validator("id", mode="before")
-    def cast_id_to_str(cls, id_value: Any) -> Optional[str]:
-        """Coerce the id field to a string."""
-        if id_value is not None:
-            return str(id_value)
-        return id_value
-
     def __init__(
         self, content: Union[str, list[Union[str, dict]]], **kwargs: Any
     ) -> None:
@@ -75,7 +68,7 @@ class BaseMessage(Serializable):
         Args:
             content: The string contents of the message.
         """
-        super().__init__(content=content, **kwargs)
+        super().__init__(content=content, **kwargs)  # type: ignore[call-arg]
 
     @classmethod
     def is_lc_serializable(cls) -> bool:

libs/core/langchain_core/outputs/chat_generation.py

@@ -2,17 +2,15 @@
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Literal, Union
+from typing import Literal, Union
 
 from pydantic import model_validator
+from typing_extensions import Self
 
 from langchain_core.messages import BaseMessage, BaseMessageChunk
 from langchain_core.outputs.generation import Generation
 from langchain_core.utils._merge import merge_dicts
 
-if TYPE_CHECKING:
-    from typing_extensions import Self
-
 
 class ChatGeneration(Generation):
     """A single chat generation output.
@@ -115,3 +113,16 @@ class ChatGenerationChunk(ChatGeneration):
             )
         msg = f"unsupported operand type(s) for +: '{type(self)}' and '{type(other)}'"
         raise TypeError(msg)
+
+
+def merge_chat_generation_chunks(
+    chunks: list[ChatGenerationChunk],
+) -> Union[ChatGenerationChunk, None]:
+    """Merge a list of ChatGenerationChunks into a single ChatGenerationChunk."""
+    if not chunks:
+        return None
+
+    if len(chunks) == 1:
+        return chunks[0]
+
+    return chunks[0] + chunks[1:]

libs/core/langchain_core/prompts/string.py

@@ -98,7 +98,7 @@ def _get_jinja2_variables_from_template(template: str) -> set[str]:
         raise ImportError(msg) from e
     env = Environment()  # noqa: S701
     ast = env.parse(template)
-    return meta.find_undeclared_variables(ast)
+    return meta.find_undeclared_variables(ast)  # type: ignore[no-untyped-call]
 
 
 def mustache_formatter(template: str, /, **kwargs: Any) -> str: