diff --git a/agentops/event.py b/agentops/event.py
index c6200aca1..1ed356bfb 100644
--- a/agentops/event.py
+++ b/agentops/event.py
@@ -5,12 +5,13 @@
     Event: Represents discrete events to be recorded.
 """
 
+import traceback
 from dataclasses import dataclass, field
 from typing import Any, Dict, List, Optional, Sequence, Union
-from .helpers import get_ISO_time, check_call_stack_for_agent_id
-from .enums import EventType
 from uuid import UUID, uuid4
-import traceback
+
+from .enums import EventType
+from .helpers import check_call_stack_for_agent_id, get_ISO_time
 
 
 @dataclass
@@ -25,6 +26,7 @@ class Event:
     end_timestamp(str): A timestamp indicating when the event ended. Defaults to the time when this Event was instantiated.
     agent_id(UUID, optional): The unique identifier of the agent that triggered the event.
     id(UUID): A unique identifier for the event. Defaults to a new UUID.
+    session_id(UUID, optional): The unique identifier of the session that the event belongs to.
 
     foo(x=1) {
         ...
@@ -43,6 +45,7 @@ class Event:
     end_timestamp: Optional[str] = None
     agent_id: Optional[UUID] = field(default_factory=check_call_stack_for_agent_id)
     id: UUID = field(default_factory=uuid4)
+    session_id: Optional[UUID] = None
 
 
 @dataclass
@@ -105,7 +108,7 @@ class ToolEvent(Event):
 
 
 @dataclass
-class ErrorEvent:
+class ErrorEvent(Event):
     """
     For recording any errors e.g. ones related to agent execution
 
@@ -115,21 +118,31 @@ class ErrorEvent:
     code(str, optional): A code that can be used to identify the error e.g. 501.
     details(str, optional): Detailed information about the error.
     logs(str, optional): For detailed information/logging related to the error.
-    timestamp(str): A timestamp indicating when the error occurred. Defaults to the time when this ErrorEvent was instantiated.
-
     """
 
+    # Inherit common Event fields
+    event_type: str = field(default=EventType.ERROR.value)
+
+    # Error-specific fields
     trigger_event: Optional[Event] = None
     exception: Optional[BaseException] = None
     error_type: Optional[str] = None
     code: Optional[str] = None
     details: Optional[Union[str, Dict[str, str]]] = None
     logs: Optional[str] = field(default_factory=traceback.format_exc)
-    timestamp: str = field(default_factory=get_ISO_time)
 
     def __post_init__(self):
-        self.event_type = EventType.ERROR.value
+        """Process exception if provided"""
         if self.exception:
             self.error_type = self.error_type or type(self.exception).__name__
             self.details = self.details or str(self.exception)
             self.exception = None  # removes exception from serialization
+
+        # Ensure end timestamp is set
+        if not self.end_timestamp:
+            self.end_timestamp = get_ISO_time()
+
+    @property
+    def timestamp(self) -> str:
+        """Maintain backward compatibility with old code expecting timestamp"""
+        return self.init_timestamp