Revert #15326

libs/community/langchain_community/callbacks/tracers/__init__.py

@@ -1,6 +1,7 @@
 """Tracers that record execution of LangChain runs."""
 
 from langchain_core.tracers.langchain import LangChainTracer
+from langchain_core.tracers.langchain_v1 import LangChainTracerV1
 from langchain_core.tracers.stdout import (
     ConsoleCallbackHandler,
     FunctionCallbackHandler,
@@ -12,5 +13,6 @@
     "ConsoleCallbackHandler",
     "FunctionCallbackHandler",
     "LangChainTracer",
+    "LangChainTracerV1",
     "WandbTracer",
 ]

libs/community/tests/integration_tests/callbacks/test_langchain_tracer.py

@@ -5,7 +5,7 @@
 from aiohttp import ClientSession
 from langchain_core.callbacks.manager import atrace_as_chain_group, trace_as_chain_group
 from langchain_core.prompts import PromptTemplate
-from langchain_core.tracers.context import tracing_v2_enabled
+from langchain_core.tracers.context import tracing_enabled, tracing_v2_enabled
 
 from langchain_community.chat_models import ChatOpenAI
 from langchain_community.llms import OpenAI
@@ -76,6 +76,63 @@ async def test_tracing_concurrent() -> None:
     await aiosession.close()
 
 
+async def test_tracing_concurrent_bw_compat_environ() -> None:
+    from langchain.agents import AgentType, initialize_agent, load_tools
+
+    os.environ["LANGCHAIN_HANDLER"] = "langchain"
+    if "LANGCHAIN_TRACING" in os.environ:
+        del os.environ["LANGCHAIN_TRACING"]
+    aiosession = ClientSession()
+    llm = OpenAI(temperature=0)
+    async_tools = load_tools(["llm-math", "serpapi"], llm=llm, aiosession=aiosession)
+    agent = initialize_agent(
+        async_tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
+    )
+    tasks = [agent.arun(q) for q in questions[:3]]
+    await asyncio.gather(*tasks)
+    await aiosession.close()
+    if "LANGCHAIN_HANDLER" in os.environ:
+        del os.environ["LANGCHAIN_HANDLER"]
+
+
+def test_tracing_context_manager() -> None:
+    from langchain.agents import AgentType, initialize_agent, load_tools
+
+    llm = OpenAI(temperature=0)
+    tools = load_tools(["llm-math", "serpapi"], llm=llm)
+    agent = initialize_agent(
+        tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
+    )
+    if "LANGCHAIN_TRACING" in os.environ:
+        del os.environ["LANGCHAIN_TRACING"]
+    with tracing_enabled() as session:
+        assert session
+        agent.run(questions[0])  # this should be traced
+
+    agent.run(questions[0])  # this should not be traced
+
+
+async def test_tracing_context_manager_async() -> None:
+    from langchain.agents import AgentType, initialize_agent, load_tools
+
+    llm = OpenAI(temperature=0)
+    async_tools = load_tools(["llm-math", "serpapi"], llm=llm)
+    agent = initialize_agent(
+        async_tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
+    )
+    if "LANGCHAIN_TRACING" in os.environ:
+        del os.environ["LANGCHAIN_TRACING"]
+
+    # start a background task
+    task = asyncio.create_task(agent.arun(questions[0]))  # this should not be traced
+    with tracing_enabled() as session:
+        assert session
+        tasks = [agent.arun(q) for q in questions[1:4]]  # these should be traced
+        await asyncio.gather(*tasks)
+
+    await task
+
+
 async def test_tracing_v2_environment_variable() -> None:
     from langchain.agents import AgentType, initialize_agent, load_tools
 

libs/core/langchain_core/callbacks/manager.py

@@ -1847,6 +1847,7 @@ def _configure(
         _configure_hooks,
         _get_tracer_project,
         _tracing_v2_is_enabled,
+        tracing_callback_var,
         tracing_v2_callback_var,
     )
 
@@ -1885,20 +1886,27 @@ def _configure(
         callback_manager.add_metadata(inheritable_metadata or {})
         callback_manager.add_metadata(local_metadata or {}, False)
 
+    tracer = tracing_callback_var.get()
+    tracing_enabled_ = (
+        env_var_is_set("LANGCHAIN_TRACING")
+        or tracer is not None
+        or env_var_is_set("LANGCHAIN_HANDLER")
+    )
+
     tracer_v2 = tracing_v2_callback_var.get()
     tracing_v2_enabled_ = _tracing_v2_is_enabled()
     tracer_project = _get_tracer_project()
     debug = _get_debug()
-    if verbose or debug or tracing_v2_enabled_:
+    if verbose or debug or tracing_enabled_ or tracing_v2_enabled_:
         from langchain_core.tracers.langchain import LangChainTracer
+        from langchain_core.tracers.langchain_v1 import LangChainTracerV1
         from langchain_core.tracers.stdout import ConsoleCallbackHandler
 
         if verbose and not any(
             isinstance(handler, StdOutCallbackHandler)
             for handler in callback_manager.handlers
         ):
             if debug:
-                # We will use ConsoleCallbackHandler instead of StdOutCallbackHandler
                 pass
             else:
                 callback_manager.add_handler(StdOutCallbackHandler(), False)
@@ -1907,6 +1915,16 @@ def _configure(
             for handler in callback_manager.handlers
         ):
             callback_manager.add_handler(ConsoleCallbackHandler(), True)
+        if tracing_enabled_ and not any(
+            isinstance(handler, LangChainTracerV1)
+            for handler in callback_manager.handlers
+        ):
+            if tracer:
+                callback_manager.add_handler(tracer, True)
+            else:
+                handler = LangChainTracerV1()
+                handler.load_session(tracer_project)
+                callback_manager.add_handler(handler, True)
         if tracing_v2_enabled_ and not any(
             isinstance(handler, LangChainTracer)
             for handler in callback_manager.handlers

libs/core/langchain_core/tracers/context.py

@@ -19,7 +19,9 @@
 from langsmith.run_helpers import get_run_tree_context
 
 from langchain_core.tracers.langchain import LangChainTracer
+from langchain_core.tracers.langchain_v1 import LangChainTracerV1
 from langchain_core.tracers.run_collector import RunCollectorCallbackHandler
+from langchain_core.tracers.schemas import TracerSessionV1
 from langchain_core.utils.env import env_var_is_set
 
 if TYPE_CHECKING:
@@ -28,6 +30,10 @@
     from langchain_core.callbacks.base import BaseCallbackHandler, Callbacks
     from langchain_core.callbacks.manager import AsyncCallbackManager, CallbackManager
 
+tracing_callback_var: ContextVar[Optional[LangChainTracerV1]] = ContextVar(  # noqa: E501
+    "tracing_callback", default=None
+)
+
 tracing_v2_callback_var: ContextVar[Optional[LangChainTracer]] = ContextVar(  # noqa: E501
     "tracing_callback_v2", default=None
 )
@@ -36,6 +42,32 @@
 )
 
 
+@contextmanager
+def tracing_enabled(
+    session_name: str = "default",
+) -> Generator[TracerSessionV1, None, None]:
+    """Get the Deprecated LangChainTracer in a context manager.
+
+    Args:
+        session_name (str, optional): The name of the session.
+          Defaults to "default".
+
+    Returns:
+        TracerSessionV1: The LangChainTracer session.
+
+    Example:
+        >>> with tracing_enabled() as session:
+        ...     # Use the LangChainTracer session
+    """
+    cb = LangChainTracerV1()
+    session = cast(TracerSessionV1, cb.load_session(session_name))
+    try:
+        tracing_callback_var.set(cb)
+        yield session
+    finally:
+        tracing_callback_var.set(None)
+
+
 @contextmanager
 def tracing_v2_enabled(
     project_name: Optional[str] = None,
@@ -136,7 +168,6 @@ def _tracing_v2_is_enabled() -> bool:
         env_var_is_set("LANGCHAIN_TRACING_V2")
         or tracing_v2_callback_var.get() is not None
         or get_run_tree_context() is not None
-        or env_var_is_set("LANGCHAIN_TRACING")
     )
 
 

libs/core/langchain_core/tracers/langchain_v1.py

@@ -0,0 +1,185 @@
+from __future__ import annotations
+
+import logging
+import os
+from typing import Any, Dict, Optional, Union
+
+import requests
+
+from langchain_core.messages import get_buffer_string
+from langchain_core.tracers.base import BaseTracer
+from langchain_core.tracers.schemas import (
+    ChainRun,
+    LLMRun,
+    Run,
+    ToolRun,
+    TracerSession,
+    TracerSessionV1,
+    TracerSessionV1Base,
+)
+from langchain_core.utils import raise_for_status_with_text
+
+logger = logging.getLogger(__name__)
+
+
+def get_headers() -> Dict[str, Any]:
+    """Get the headers for the LangChain API."""
+    headers: Dict[str, Any] = {"Content-Type": "application/json"}
+    if os.getenv("LANGCHAIN_API_KEY"):
+        headers["x-api-key"] = os.getenv("LANGCHAIN_API_KEY")
+    return headers
+
+
+def _get_endpoint() -> str:
+    return os.getenv("LANGCHAIN_ENDPOINT", "http://localhost:8000")
+
+
+class LangChainTracerV1(BaseTracer):
+    """An implementation of the SharedTracer that POSTS to the langchain endpoint."""
+
+    def __init__(self, **kwargs: Any) -> None:
+        """Initialize the LangChain tracer."""
+        super().__init__(**kwargs)
+        self.session: Optional[TracerSessionV1] = None
+        self._endpoint = _get_endpoint()
+        self._headers = get_headers()
+
+    def _convert_to_v1_run(self, run: Run) -> Union[LLMRun, ChainRun, ToolRun]:
+        session = self.session or self.load_default_session()
+        if not isinstance(session, TracerSessionV1):
+            raise ValueError(
+                "LangChainTracerV1 is not compatible with"
+                f" session of type {type(session)}"
+            )
+
+        if run.run_type == "llm":
+            if "prompts" in run.inputs:
+                prompts = run.inputs["prompts"]
+            elif "messages" in run.inputs:
+                prompts = [get_buffer_string(batch) for batch in run.inputs["messages"]]
+            else:
+                raise ValueError("No prompts found in LLM run inputs")
+            return LLMRun(
+                uuid=str(run.id) if run.id else None,
+                parent_uuid=str(run.parent_run_id) if run.parent_run_id else None,
+                start_time=run.start_time,
+                end_time=run.end_time,
+                extra=run.extra,
+                execution_order=run.execution_order,
+                child_execution_order=run.child_execution_order,
+                serialized=run.serialized,
+                session_id=session.id,
+                error=run.error,
+                prompts=prompts,
+                response=run.outputs if run.outputs else None,
+            )
+        if run.run_type == "chain":
+            child_runs = [self._convert_to_v1_run(run) for run in run.child_runs]
+            return ChainRun(
+                uuid=str(run.id) if run.id else None,
+                parent_uuid=str(run.parent_run_id) if run.parent_run_id else None,
+                start_time=run.start_time,
+                end_time=run.end_time,
+                execution_order=run.execution_order,
+                child_execution_order=run.child_execution_order,
+                serialized=run.serialized,
+                session_id=session.id,
+                inputs=run.inputs,
+                outputs=run.outputs,
+                error=run.error,
+                extra=run.extra,
+                child_llm_runs=[run for run in child_runs if isinstance(run, LLMRun)],
+                child_chain_runs=[
+                    run for run in child_runs if isinstance(run, ChainRun)
+                ],
+                child_tool_runs=[run for run in child_runs if isinstance(run, ToolRun)],
+            )
+        if run.run_type == "tool":
+            child_runs = [self._convert_to_v1_run(run) for run in run.child_runs]
+            return ToolRun(
+                uuid=str(run.id) if run.id else None,
+                parent_uuid=str(run.parent_run_id) if run.parent_run_id else None,
+                start_time=run.start_time,
+                end_time=run.end_time,
+                execution_order=run.execution_order,
+                child_execution_order=run.child_execution_order,
+                serialized=run.serialized,
+                session_id=session.id,
+                action=str(run.serialized),
+                tool_input=run.inputs.get("input", ""),
+                output=None if run.outputs is None else run.outputs.get("output"),
+                error=run.error,
+                extra=run.extra,
+                child_chain_runs=[
+                    run for run in child_runs if isinstance(run, ChainRun)
+                ],
+                child_tool_runs=[run for run in child_runs if isinstance(run, ToolRun)],
+                child_llm_runs=[run for run in child_runs if isinstance(run, LLMRun)],
+            )
+        raise ValueError(f"Unknown run type: {run.run_type}")
+
+    def _persist_run(self, run: Union[Run, LLMRun, ChainRun, ToolRun]) -> None:
+        """Persist a run."""
+        if isinstance(run, Run):
+            v1_run = self._convert_to_v1_run(run)
+        else:
+            v1_run = run
+        if isinstance(v1_run, LLMRun):
+            endpoint = f"{self._endpoint}/llm-runs"
+        elif isinstance(v1_run, ChainRun):
+            endpoint = f"{self._endpoint}/chain-runs"
+        else:
+            endpoint = f"{self._endpoint}/tool-runs"
+
+        try:
+            response = requests.post(
+                endpoint,
+                data=v1_run.json(),
+                headers=self._headers,
+            )
+            raise_for_status_with_text(response)
+        except Exception as e:
+            logger.warning(f"Failed to persist run: {e}")
+
+    def _persist_session(
+        self, session_create: TracerSessionV1Base
+    ) -> Union[TracerSessionV1, TracerSession]:
+        """Persist a session."""
+        try:
+            r = requests.post(
+                f"{self._endpoint}/sessions",
+                data=session_create.json(),
+                headers=self._headers,
+            )
+            session = TracerSessionV1(id=r.json()["id"], **session_create.dict())
+        except Exception as e:
+            logger.warning(f"Failed to create session, using default session: {e}")
+            session = TracerSessionV1(id=1, **session_create.dict())
+        return session
+
+    def _load_session(self, session_name: Optional[str] = None) -> TracerSessionV1:
+        """Load a session from the tracer."""
+        try:
+            url = f"{self._endpoint}/sessions"
+            if session_name:
+                url += f"?name={session_name}"
+            r = requests.get(url, headers=self._headers)
+
+            tracer_session = TracerSessionV1(**r.json()[0])
+        except Exception as e:
+            session_type = "default" if not session_name else session_name
+            logger.warning(
+                f"Failed to load {session_type} session, using empty session: {e}"
+            )
+            tracer_session = TracerSessionV1(id=1)
+
+        self.session = tracer_session
+        return tracer_session
+
+    def load_session(self, session_name: str) -> Union[TracerSessionV1, TracerSession]:
+        """Load a session with the given name from the tracer."""
+        return self._load_session(session_name)
+
+    def load_default_session(self) -> Union[TracerSessionV1, TracerSession]:
+        """Load the default tracing session and set it as the Tracer's session."""
+        return self._load_session("default")