core docstrings tracers update (#24211)

Added missed docstrings. Formatted docstrings to the consistent form.

libs/core/langchain_core/tracers/base.py

@@ -62,7 +62,21 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Start a trace for an LLM run."""
+        """Start a trace for an LLM run.
+
+        Args:
+            serialized: The serialized model.
+            messages: The messages to start the chat with.
+            run_id: The run ID.
+            tags: The tags for the run. Defaults to None.
+            parent_run_id: The parent run ID. Defaults to None.
+            metadata: The metadata for the run. Defaults to None.
+            name: The name of the run.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         chat_model_run = self._create_chat_model_run(
             serialized=serialized,
             messages=messages,
@@ -89,7 +103,21 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Start a trace for an LLM run."""
+        """Start a trace for an LLM run.
+
+        Args:
+            serialized: The serialized model.
+            prompts: The prompts to start the LLM with.
+            run_id: The run ID.
+            tags: The tags for the run. Defaults to None.
+            parent_run_id: The parent run ID. Defaults to None.
+            metadata: The metadata for the run. Defaults to None.
+            name: The name of the run.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         llm_run = self._create_llm_run(
             serialized=serialized,
             prompts=prompts,
@@ -113,7 +141,18 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         parent_run_id: Optional[UUID] = None,
         **kwargs: Any,
     ) -> Run:
-        """Run on new LLM token. Only available when streaming is enabled."""
+        """Run on new LLM token. Only available when streaming is enabled.
+
+        Args:
+            token: The token.
+            chunk: The chunk. Defaults to None.
+            run_id: The run ID.
+            parent_run_id: The parent run ID. Defaults to None.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         # "chat_model" is only used for the experimental new streaming_events format.
         # This change should not affect any existing tracers.
         llm_run = self._llm_run_with_token_event(
@@ -133,6 +172,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         run_id: UUID,
         **kwargs: Any,
     ) -> Run:
+        """Run on retry.
+
+        Args:
+            retry_state: The retry state.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         llm_run = self._llm_run_with_retry_event(
             retry_state=retry_state,
             run_id=run_id,
@@ -140,7 +189,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         return llm_run
 
     def on_llm_end(self, response: LLMResult, *, run_id: UUID, **kwargs: Any) -> Run:
-        """End a trace for an LLM run."""
+        """End a trace for an LLM run.
+
+        Args:
+            response: The response.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         # "chat_model" is only used for the experimental new streaming_events format.
         # This change should not affect any existing tracers.
         llm_run = self._complete_llm_run(
@@ -158,7 +216,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         run_id: UUID,
         **kwargs: Any,
     ) -> Run:
-        """Handle an error for an LLM run."""
+        """Handle an error for an LLM run.
+
+        Args:
+            error: The error.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         # "chat_model" is only used for the experimental new streaming_events format.
         # This change should not affect any existing tracers.
         llm_run = self._errored_llm_run(
@@ -182,7 +249,22 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Start a trace for a chain run."""
+        """Start a trace for a chain run.
+
+        Args:
+            serialized: The serialized chain.
+            inputs: The inputs for the chain.
+            run_id: The run ID.
+            tags: The tags for the run. Defaults to None.
+            parent_run_id: The parent run ID. Defaults to None.
+            metadata: The metadata for the run. Defaults to None.
+            run_type: The type of the run. Defaults to None.
+            name: The name of the run.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         chain_run = self._create_chain_run(
             serialized=serialized,
             inputs=inputs,
@@ -206,7 +288,17 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         inputs: Optional[Dict[str, Any]] = None,
         **kwargs: Any,
     ) -> Run:
-        """End a trace for a chain run."""
+        """End a trace for a chain run.
+
+        Args:
+            outputs: The outputs for the chain.
+            run_id: The run ID.
+            inputs: The inputs for the chain. Defaults to None.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         chain_run = self._complete_chain_run(
             outputs=outputs,
             run_id=run_id,
@@ -225,7 +317,17 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         run_id: UUID,
         **kwargs: Any,
     ) -> Run:
-        """Handle an error for a chain run."""
+        """Handle an error for a chain run.
+
+        Args:
+            error: The error.
+            inputs: The inputs for the chain. Defaults to None.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         chain_run = self._errored_chain_run(
             error=error,
             run_id=run_id,
@@ -249,7 +351,22 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         inputs: Optional[Dict[str, Any]] = None,
         **kwargs: Any,
     ) -> Run:
-        """Start a trace for a tool run."""
+        """Start a trace for a tool run.
+
+        Args:
+            serialized: The serialized tool.
+            input_str: The input string.
+            run_id: The run ID.
+            tags: The tags for the run. Defaults to None.
+            parent_run_id: The parent run ID. Defaults to None.
+            metadata: The metadata for the run. Defaults to None.
+            name: The name of the run.
+            inputs: The inputs for the tool.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         tool_run = self._create_tool_run(
             serialized=serialized,
             input_str=input_str,
@@ -266,7 +383,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         return tool_run
 
     def on_tool_end(self, output: Any, *, run_id: UUID, **kwargs: Any) -> Run:
-        """End a trace for a tool run."""
+        """End a trace for a tool run.
+
+        Args:
+            output: The output for the tool.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         tool_run = self._complete_tool_run(
             output=output,
             run_id=run_id,
@@ -283,7 +409,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         run_id: UUID,
         **kwargs: Any,
     ) -> Run:
-        """Handle an error for a tool run."""
+        """Handle an error for a tool run.
+
+        Args:
+            error: The error.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         tool_run = self._errored_tool_run(
             error=error,
             run_id=run_id,
@@ -304,7 +439,21 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Run when Retriever starts running."""
+        """Run when the Retriever starts running.
+
+        Args:
+            serialized: The serialized retriever.
+            query: The query.
+            run_id: The run ID.
+            parent_run_id: The parent run ID. Defaults to None.
+            tags: The tags for the run. Defaults to None.
+            metadata: The metadata for the run. Defaults to None.
+            name: The name of the run.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         retrieval_run = self._create_retrieval_run(
             serialized=serialized,
             query=query,
@@ -326,7 +475,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
         run_id: UUID,
         **kwargs: Any,
     ) -> Run:
-        """Run when Retriever errors."""
+        """Run when Retriever errors.
+
+        Args:
+            error: The error.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         retrieval_run = self._errored_retrieval_run(
             error=error,
             run_id=run_id,
@@ -339,7 +497,16 @@ class BaseTracer(_TracerCore, BaseCallbackHandler, ABC):
     def on_retriever_end(
         self, documents: Sequence[Document], *, run_id: UUID, **kwargs: Any
     ) -> Run:
-        """Run when Retriever ends running."""
+        """Run when the Retriever ends running.
+
+        Args:
+            documents: The documents.
+            run_id: The run ID.
+            **kwargs: Additional arguments.
+
+        Returns:
+            The run.
+        """
         retrieval_run = self._complete_retrieval_run(
             documents=documents,
             run_id=run_id,

libs/core/langchain_core/tracers/context.py

@@ -68,8 +68,8 @@ def tracing_v2_enabled(
         client (LangSmithClient, optional): The client of the langsmith.
             Defaults to None.
 
-    Returns:
+    Yields:
-        None
+        LangChainTracer: The LangChain tracer.
 
     Example:
         >>> with tracing_v2_enabled():
@@ -100,7 +100,7 @@ def tracing_v2_enabled(
 def collect_runs() -> Generator[RunCollectorCallbackHandler, None, None]:
     """Collect all run traces in context.
 
-    Returns:
+    Yields:
         run_collector.RunCollectorCallbackHandler: The run collector callback handler.
 
     Example:

libs/core/langchain_core/tracers/core.py

@@ -46,7 +46,8 @@ SCHEMA_FORMAT_TYPE = Literal["original", "streaming_events"]
 
 class _TracerCore(ABC):
     """
-    Abstract base class for tracers
+    Abstract base class for tracers.
+
     This class provides common methods, and reusable methods for tracers.
     """
 
@@ -65,17 +66,18 @@ class _TracerCore(ABC):
         Args:
             _schema_format: Primarily changes how the inputs and outputs are
                 handled. For internal use only. This API will change.
+
                 - 'original' is the format used by all current tracers.
-                   This format is slightly inconsistent with respect to inputs
+                  This format is slightly inconsistent with respect to inputs
-                   and outputs.
+                  and outputs.
                 - 'streaming_events' is used for supporting streaming events,
-                   for internal usage. It will likely change in the future, or
+                  for internal usage. It will likely change in the future, or
-                   be deprecated entirely in favor of a dedicated async tracer
+                  be deprecated entirely in favor of a dedicated async tracer
-                   for streaming events.
+                  for streaming events.
                 - 'original+chat' is a format that is the same as 'original'
-                   except it does NOT raise an attribute error on_chat_model_start
+                  except it does NOT raise an attribute error on_chat_model_start
             kwargs: Additional keyword arguments that will be passed to
-                    the super class.
+                the superclass.
         """
         super().__init__(**kwargs)
         self._schema_format = _schema_format  # For internal use only API will change.
@@ -207,7 +209,7 @@ class _TracerCore(ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Create a llm run"""
+        """Create a llm run."""
         start_time = datetime.now(timezone.utc)
         if metadata:
             kwargs.update({"metadata": metadata})
@@ -234,7 +236,7 @@ class _TracerCore(ABC):
         **kwargs: Any,
     ) -> Run:
         """
-        Append token event to LLM run and return the run
+        Append token event to LLM run and return the run.
         """
         llm_run = self._get_run(run_id, run_type={"llm", "chat_model"})
         event_kwargs: Dict[str, Any] = {"token": token}
@@ -314,7 +316,7 @@ class _TracerCore(ABC):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Create a chain Run"""
+        """Create a chain Run."""
         start_time = datetime.now(timezone.utc)
         if metadata:
             kwargs.update({"metadata": metadata})

libs/core/langchain_core/tracers/evaluation.py

@@ -104,7 +104,7 @@ class EvaluatorCallbackHandler(BaseTracer):
     def _evaluate_in_project(self, run: Run, evaluator: langsmith.RunEvaluator) -> None:
         """Evaluate the run in the project.
 
-        Parameters
+        Args:
         ----------
         run : Run
             The run to be evaluated.
@@ -200,7 +200,7 @@ class EvaluatorCallbackHandler(BaseTracer):
     def _persist_run(self, run: Run) -> None:
         """Run the evaluator on the run.
 
-        Parameters
+        Args:
         ----------
         run : Run
             The run to be evaluated.

libs/core/langchain_core/tracers/event_stream.py

@@ -52,7 +52,18 @@ logger = logging.getLogger(__name__)
 
 
 class RunInfo(TypedDict):
-    """Information about a run."""
+    """Information about a run.
+
+    This is used to keep track of the metadata associated with a run.
+
+    Parameters:
+        name: The name of the run.
+        tags: The tags associated with the run.
+        metadata: The metadata associated with the run.
+        run_type: The type of the run.
+        inputs: The inputs to the run.
+        parent_run_id: The ID of the parent run.
+    """
 
     name: str
     tags: List[str]
@@ -150,7 +161,19 @@ class _AstreamEventsCallbackHandler(AsyncCallbackHandler, _StreamingCallbackHand
     async def tap_output_aiter(
         self, run_id: UUID, output: AsyncIterator[T]
     ) -> AsyncIterator[T]:
-        """Tap the output aiter."""
+        """Tap the output aiter.
+
+        This method is used to tap the output of a Runnable that produces
+        an async iterator. It is used to generate stream events for the
+        output of the Runnable.
+
+        Args:
+            run_id: The ID of the run.
+            output: The output of the Runnable.
+
+        Yields:
+            T: The output of the Runnable.
+        """
         sentinel = object()
         # atomic check and set
         tap = self.is_tapped.setdefault(run_id, sentinel)
@@ -192,7 +215,15 @@ class _AstreamEventsCallbackHandler(AsyncCallbackHandler, _StreamingCallbackHand
                 yield chunk
 
     def tap_output_iter(self, run_id: UUID, output: Iterator[T]) -> Iterator[T]:
-        """Tap the output aiter."""
+        """Tap the output aiter.
+
+        Args:
+            run_id: The ID of the run.
+            output: The output of the Runnable.
+
+        Yields:
+            T: The output of the Runnable.
+        """
         sentinel = object()
         # atomic check and set
         tap = self.is_tapped.setdefault(run_id, sentinel)

libs/core/langchain_core/tracers/langchain.py

@@ -32,7 +32,12 @@ _EXECUTOR: Optional[ThreadPoolExecutor] = None
 
 
 def log_error_once(method: str, exception: Exception) -> None:
-    """Log an error once."""
+    """Log an error once.
+
+    Args:
+        method: The method that raised the exception.
+        exception: The exception that was raised.
+    """
     global _LOGGED
     if (method, type(exception)) in _LOGGED:
         return
@@ -82,7 +87,15 @@ class LangChainTracer(BaseTracer):
         tags: Optional[List[str]] = None,
         **kwargs: Any,
     ) -> None:
-        """Initialize the LangChain tracer."""
+        """Initialize the LangChain tracer.
+
+        Args:
+            example_id: The example ID.
+            project_name: The project name. Defaults to the tracer project.
+            client: The client. Defaults to the global client.
+            tags: The tags. Defaults to an empty list.
+            **kwargs: Additional keyword arguments.
+        """
         super().__init__(**kwargs)
         self.example_id = (
             UUID(example_id) if isinstance(example_id, str) else example_id
@@ -104,7 +117,21 @@ class LangChainTracer(BaseTracer):
         name: Optional[str] = None,
         **kwargs: Any,
     ) -> Run:
-        """Start a trace for an LLM run."""
+        """Start a trace for an LLM run.
+
+        Args:
+            serialized: The serialized model.
+            messages: The messages.
+            run_id: The run ID.
+            tags: The tags. Defaults to None.
+            parent_run_id: The parent run ID. Defaults to None.
+            metadata: The metadata. Defaults to None.
+            name: The name. Defaults to None.
+            **kwargs: Additional keyword arguments.
+
+        Returns:
+            Run: The run.
+        """
         start_time = datetime.now(timezone.utc)
         if metadata:
             kwargs.update({"metadata": metadata})
@@ -130,7 +157,15 @@ class LangChainTracer(BaseTracer):
         self.latest_run = run_
 
     def get_run_url(self) -> str:
-        """Get the LangSmith root run URL"""
+        """Get the LangSmith root run URL.
+
+        Returns:
+            str: The LangSmith root run URL.
+
+        Raises:
+            ValueError: If no traced run is found.
+            ValueError: If the run URL cannot be found.
+        """
         if not self.latest_run:
             raise ValueError("No traced run found.")
         # If this is the first run in a project, the project may not yet be created.

libs/core/langchain_core/tracers/log_stream.py

@@ -189,12 +189,15 @@ class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
                 handled.
                 **For internal use only. This API will change.**
                 - 'original' is the format used by all current tracers.
-                   This format is slightly inconsistent with respect to inputs
+                  This format is slightly inconsistent with respect to inputs
-                   and outputs.
+                  and outputs.
                 - 'streaming_events' is used for supporting streaming events,
-                   for internal usage. It will likely change in the future, or
+                  for internal usage. It will likely change in the future, or
-                   be deprecated entirely in favor of a dedicated async tracer
+                  be deprecated entirely in favor of a dedicated async tracer
-                   for streaming events.
+                  for streaming events.
+
+        Raises:
+            ValueError: If an invalid schema format is provided (internal use only).
         """
         if _schema_format not in {"original", "streaming_events"}:
             raise ValueError(
@@ -224,7 +227,15 @@ class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
         return self.receive_stream.__aiter__()
 
     def send(self, *ops: Dict[str, Any]) -> bool:
-        """Send a patch to the stream, return False if the stream is closed."""
+        """Send a patch to the stream, return False if the stream is closed.
+
+        Args:
+            *ops: The operations to send to the stream.
+
+        Returns:
+            bool: True if the patch was sent successfully, False if the stream
+                is closed.
+        """
         # We will likely want to wrap this in try / except at some point
         # to handle exceptions that might arise at run time.
         # For now we'll let the exception bubble up, and always return
@@ -235,7 +246,15 @@ class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
     async def tap_output_aiter(
         self, run_id: UUID, output: AsyncIterator[T]
     ) -> AsyncIterator[T]:
-        """Tap an output async iterator to stream its values to the log."""
+        """Tap an output async iterator to stream its values to the log.
+
+        Args:
+            run_id: The ID of the run.
+            output: The output async iterator.
+
+        Yields:
+            T: The output value.
+        """
         async for chunk in output:
             # root run is handled in .astream_log()
             if run_id != self.root_id:
@@ -254,7 +273,15 @@ class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
             yield chunk
 
     def tap_output_iter(self, run_id: UUID, output: Iterator[T]) -> Iterator[T]:
-        """Tap an output async iterator to stream its values to the log."""
+        """Tap an output async iterator to stream its values to the log.
+
+        Args:
+            run_id: The ID of the run.
+            output: The output iterator.
+
+        Yields:
+            T: The output value.
+        """
         for chunk in output:
             # root run is handled in .astream_log()
             if run_id != self.root_id:
@@ -273,6 +300,14 @@ class LogStreamCallbackHandler(BaseTracer, _StreamingCallbackHandler):
             yield chunk
 
     def include_run(self, run: Run) -> bool:
+        """Check if a Run should be included in the log.
+
+        Args:
+            run: The Run to check.
+
+        Returns:
+            bool: True if the run should be included, False otherwise.
+        """
         if run.id == self.root_id:
             return False
 
@@ -454,7 +489,7 @@ def _get_standardized_inputs(
     Returns:
         Valid inputs are only dict. By conventions, inputs always represented
         invocation using named arguments.
-        A None means that the input is not yet known!
+        None means that the input is not yet known!
     """
     if schema_format == "original":
         raise NotImplementedError(

libs/core/langchain_core/tracers/memory_stream.py

@@ -33,11 +33,27 @@ class _SendStream(Generic[T]):
         self._done = done
 
     async def send(self, item: T) -> None:
-        """Schedule the item to be written to the queue using the original loop."""
+        """Schedule the item to be written to the queue using the original loop.
+
+        This is a coroutine that can be awaited.
+
+        Args:
+            item: The item to write to the queue.
+        """
         return self.send_nowait(item)
 
     def send_nowait(self, item: T) -> None:
-        """Schedule the item to be written to the queue using the original loop."""
+        """Schedule the item to be written to the queue using the original loop.
+
+        This is a non-blocking call.
+
+        Args:
+            item: The item to write to the queue.
+
+        Raises:
+            RuntimeError: If the event loop is already closed when trying to write
+                            to the queue.
+        """
         try:
             self._reader_loop.call_soon_threadsafe(self._queue.put_nowait, item)
         except RuntimeError:
@@ -45,11 +61,18 @@ class _SendStream(Generic[T]):
                 raise  # Raise the exception if the loop is not closed
 
     async def aclose(self) -> None:
-        """Schedule the done object write the queue using the original loop."""
+        """Async schedule the done object write the queue using the original loop."""
         return self.close()
 
     def close(self) -> None:
-        """Schedule the done object write the queue using the original loop."""
+        """Schedule the done object write the queue using the original loop.
+
+        This is a non-blocking call.
+
+        Raises:
+            RuntimeError: If the event loop is already closed when trying to write
+                            to the queue.
+        """
         try:
             self._reader_loop.call_soon_threadsafe(self._queue.put_nowait, self._done)
         except RuntimeError:
@@ -87,7 +110,7 @@ class _MemoryStream(Generic[T]):
 
     This implementation is meant to be used with a single writer and a single reader.
 
-    This is an internal implementation to LangChain please do not use it directly.
+    This is an internal implementation to LangChain. Please do not use it directly.
     """
 
     def __init__(self, loop: AbstractEventLoop) -> None:
@@ -103,11 +126,19 @@ class _MemoryStream(Generic[T]):
         self._done = object()
 
     def get_send_stream(self) -> _SendStream[T]:
-        """Get a writer for the channel."""
+        """Get a writer for the channel.
+
+        Returns:
+            _SendStream: The writer for the channel.
+        """
         return _SendStream[T](
             reader_loop=self._loop, queue=self._queue, done=self._done
         )
 
     def get_receive_stream(self) -> _ReceiveStream[T]:
-        """Get a reader for the channel."""
+        """Get a reader for the channel.
+
+        Returns:
+            _ReceiveStream: The reader for the channel.
+        """
         return _ReceiveStream[T](queue=self._queue, done=self._done)

libs/core/langchain_core/tracers/root_listeners.py

@@ -16,7 +16,16 @@ AsyncListener = Union[
 
 
 class RootListenersTracer(BaseTracer):
-    """Tracer that calls listeners on run start, end, and error."""
+    """Tracer that calls listeners on run start, end, and error.
+
+    Parameters:
+        log_missing_parent: Whether to log a warning if the parent is missing.
+            Default is False.
+        config: The runnable config.
+        on_start: The listener to call on run start.
+        on_end: The listener to call on run end.
+        on_error: The listener to call on run error.
+    """
 
     log_missing_parent = False
 
@@ -28,6 +37,14 @@ class RootListenersTracer(BaseTracer):
         on_end: Optional[Listener],
         on_error: Optional[Listener],
     ) -> None:
+        """Initialize the tracer.
+
+        Args:
+            config: The runnable config.
+            on_start: The listener to call on run start.
+            on_end: The listener to call on run end.
+            on_error: The listener to call on run error
+        """
         super().__init__(_schema_format="original+chat")
 
         self.config = config
@@ -63,7 +80,16 @@ class RootListenersTracer(BaseTracer):
 
 
 class AsyncRootListenersTracer(AsyncBaseTracer):
-    """Async Tracer that calls listeners on run start, end, and error."""
+    """Async Tracer that calls listeners on run start, end, and error.
+
+    Parameters:
+        log_missing_parent: Whether to log a warning if the parent is missing.
+            Default is False.
+        config: The runnable config.
+        on_start: The listener to call on run start.
+        on_end: The listener to call on run end.
+        on_error: The listener to call on run error.
+    """
 
     log_missing_parent = False
 
@@ -75,6 +101,14 @@ class AsyncRootListenersTracer(AsyncBaseTracer):
         on_end: Optional[AsyncListener],
         on_error: Optional[AsyncListener],
     ) -> None:
+        """Initialize the tracer.
+
+        Args:
+            config: The runnable config.
+            on_start: The listener to call on run start.
+            on_end: The listener to call on run end.
+            on_error: The listener to call on run error
+        """
         super().__init__(_schema_format="original+chat")
 
         self.config = config

libs/core/langchain_core/tracers/run_collector.py

@@ -8,13 +8,13 @@ from langchain_core.tracers.schemas import Run
 
 
 class RunCollectorCallbackHandler(BaseTracer):
-    """
+    """Tracer that collects all nested runs in a list.
-    Tracer that collects all nested runs in a list.
 
     This tracer is useful for inspection and evaluation purposes.
 
     Parameters
     ----------
+    name : str, default="run-collector_callback_handler"
     example_id : Optional[Union[UUID, str]], default=None
         The ID of the example being traced. It can be either a UUID or a string.
     """
@@ -31,6 +31,8 @@ class RunCollectorCallbackHandler(BaseTracer):
         ----------
         example_id : Optional[Union[UUID, str]], default=None
             The ID of the example being traced. It can be either a UUID or a string.
+        **kwargs : Any
+            Additional keyword arguments
         """
         super().__init__(**kwargs)
         self.example_id = (

libs/core/langchain_core/tracers/schemas.py

@@ -112,7 +112,15 @@ class ToolRun(BaseRun):
 
 
 class Run(BaseRunV2):
-    """Run schema for the V2 API in the Tracer."""
+    """Run schema for the V2 API in the Tracer.
+
+    Parameters:
+        child_runs: The child runs.
+        tags: The tags. Default is an empty list.
+        events: The events. Default is an empty list.
+        trace_id: The trace ID. Default is None.
+        dotted_order: The dotted order.
+    """
 
     child_runs: List[Run] = Field(default_factory=list)
     tags: Optional[List[str]] = Field(default_factory=list)

libs/core/langchain_core/tracers/stdout.py

@@ -7,15 +7,14 @@ from langchain_core.utils.input import get_bolded_text, get_colored_text
 
 
 def try_json_stringify(obj: Any, fallback: str) -> str:
-    """
+    """Try to stringify an object to JSON.
-    Try to stringify an object to JSON.
+
     Args:
         obj: Object to stringify.
         fallback: Fallback string to return if the object cannot be stringified.
 
     Returns:
         A JSON string if the object can be stringified, otherwise the fallback string.
-
     """
     try:
         return json.dumps(obj, indent=2, ensure_ascii=False)
@@ -45,6 +44,8 @@ class FunctionCallbackHandler(BaseTracer):
     """Tracer that calls a function with a single str parameter."""
 
     name: str = "function_callback_handler"
+    """The name of the tracer. This is used to identify the tracer in the logs.
+    Default is "function_callback_handler"."""
 
     def __init__(self, function: Callable[[str], None], **kwargs: Any) -> None:
         super().__init__(**kwargs)
@@ -54,6 +55,14 @@ class FunctionCallbackHandler(BaseTracer):
         pass
 
     def get_parents(self, run: Run) -> List[Run]:
+        """Get the parents of a run.
+
+        Args:
+            run: The run to get the parents of.
+
+        Returns:
+            A list of parent runs.
+        """
         parents = []
         current_run = run
         while current_run.parent_run_id:
@@ -66,6 +75,14 @@ class FunctionCallbackHandler(BaseTracer):
         return parents
 
     def get_breadcrumbs(self, run: Run) -> str:
+        """Get the breadcrumbs of a run.
+
+        Args:
+            run: The run to get the breadcrumbs of.
+
+        Returns:
+            A string with the breadcrumbs of the run.
+        """
         parents = self.get_parents(run)[::-1]
         string = " > ".join(
             f"{parent.run_type}:{parent.name}"