diff --git a/quotientai/async_client.py b/quotientai/async_client.py
index f0b6556..7e0b95f 100644
--- a/quotientai/async_client.py
+++ b/quotientai/async_client.py
@@ -30,6 +30,7 @@ def __init__(self, api_key: str):
         self.token = None
         self.token_expiry = 0
         self.token_api_key = None
+        self._user = None
         self._token_path = (
             token_dir
             / ".quotient"
diff --git a/quotientai/client.py b/quotientai/client.py
index 5a354eb..0248044 100644
--- a/quotientai/client.py
+++ b/quotientai/client.py
@@ -32,6 +32,7 @@ def __init__(self, api_key: str):
         self.token = None
         self.token_expiry = 0
         self.token_api_key = None
+        self._user = None
         self._token_path = (
             token_dir
             / ".quotient"
diff --git a/quotientai/resources/auth.py b/quotientai/resources/auth.py
index 6e459e8..3b94a19 100644
--- a/quotientai/resources/auth.py
+++ b/quotientai/resources/auth.py
@@ -8,6 +8,11 @@ def authenticate(self):
         A call to GET /auth/profile to initially authenticate the user.
         """
         response = self._client._get("/auth/profile")
+        
+        # Set the user_id if successful
+        if response and isinstance(response, dict) and 'user_id' in response:
+            self._client._user = response['user_id']
+        
         return response
     
 class AsyncAuthResource:
@@ -25,6 +30,11 @@ def authenticate(self):
             task = loop.create_task(self._client._get("/auth/profile"))
             # Run the task to completion
             result = loop.run_until_complete(task)
+            
+            # Set the user_id if successful
+            if result and isinstance(result, dict) and 'user_id' in result:
+                self._client._user = result['user_id']
+            
             return result
         finally:
             loop.close()
diff --git a/quotientai/tracing/core.py b/quotientai/tracing/core.py
index cc53e57..298a903 100644
--- a/quotientai/tracing/core.py
+++ b/quotientai/tracing/core.py
@@ -42,6 +42,7 @@ class QuotientAttributes(str, Enum):
     app_name = "app.name"
     environment = "app.environment"
     detections = "quotient.detections"
+    user = "quotient.user"
 
 
 class TracingResource:
@@ -123,6 +124,17 @@ def _create_otlp_exporter(self, endpoint: str, headers: dict):
         """
         return OTLPSpanExporter(endpoint=endpoint, headers=headers)
 
+
+    def _get_user(self):
+        """
+        Get user_id from client.
+        Returns the user_id or None if not found.
+        """
+        if hasattr(self._client, '_user'):
+            return self._client._user
+        return "None"
+
+
     @functools.lru_cache()
     def _setup_auto_collector(self, app_name: str, environment: str, instruments: Optional[tuple] = None, detections: Optional[str] = None):
         """
@@ -139,6 +151,7 @@ def _setup_auto_collector(self, app_name: str, environment: str, instruments: Op
                 resource_attributes = {
                     QuotientAttributes.app_name: app_name,
                     QuotientAttributes.environment: environment,
+                    QuotientAttributes.user: self._get_user(),
                 }
                 
                 if detections is not None:
@@ -154,7 +167,7 @@ def _setup_auto_collector(self, app_name: str, environment: str, instruments: Op
                     "OTEL_EXPORTER_OTLP_ENDPOINT",
                     DEFAULT_TRACING_ENDPOINT,
                 )
-                
+
                 # Parse headers from environment or use default
                 headers = {
                     "Authorization": f"Bearer {self._client.api_key}",