feat(context fix): fixed sessions and users for langchain callback

Author: shah-siddd

src/openlayer/lib/integrations/langchain_callback.py

@@ -1,6 +1,7 @@
 """Module with the Openlayer callback handler for LangChain."""
 
 # pylint: disable=unused-argument
+import contextvars
 import time
 from typing import Any, Callable, Dict, List, Optional, Union
 from uuid import UUID
@@ -190,8 +191,9 @@ def _end_step(
         ):
             trace = self._traces_by_root.pop(run_id)
             if tracer._configured_background_publish_enabled:
+                ctx = contextvars.copy_context()
                 tracer._get_background_executor().submit(
-                    self._process_and_upload_trace, trace
+                    ctx.run, self._process_and_upload_trace, trace
                 )
             else:
                 self._process_and_upload_trace(trace)
@@ -1247,8 +1249,9 @@ def _end_step(
         if is_root_step and has_standalone_trace and not self._has_external_trace:
             trace = self._traces_by_root.pop(run_id)
             if tracer._configured_background_publish_enabled:
+                ctx = contextvars.copy_context()
                 tracer._get_background_executor().submit(
-                    self._process_and_upload_async_trace, trace
+                    ctx.run, self._process_and_upload_async_trace, trace
                 )
             else:
                 self._process_and_upload_async_trace(trace)

src/openlayer/lib/tracing/tracer.py

@@ -1631,9 +1631,12 @@ def _handle_trace_completion(
 
         if _publish:
             if _configured_background_publish_enabled:
-                # Submit to background thread pool
+                # Submit to background thread pool, copying context so that
+                # contextvars (user_id, session_id, etc.) are preserved.
+                ctx = contextvars.copy_context()
                 executor = _get_background_executor()
                 executor.submit(
+                    ctx.run,
                     _upload_and_publish_trace,
                     current_trace,
                     resolved_pipeline_id,