diff --git a/python/pyspark/sql/connect/client/core.py b/python/pyspark/sql/connect/client/core.py
index 2a2ac0e6b539..a5cc4fb3dd19 100644
--- a/python/pyspark/sql/connect/client/core.py
+++ b/python/pyspark/sql/connect/client/core.py
@@ -727,6 +727,9 @@ def __init__(
         # cleanup ml cache if possible
         atexit.register(self._cleanup_ml_cache)
 
+        self.global_user_context_extensions: List[Tuple[str, any_pb2.Any]] = []
+        self.global_user_context_extensions_lock = threading.Lock()
+
     @property
     def _stub(self) -> grpc_lib.SparkConnectServiceStub:
         if self.is_closed:
@@ -1277,6 +1280,24 @@ def token(self) -> Optional[str]:
         """
         return self._builder.token
 
+    def _update_request_with_user_context_extensions(
+            self,
+            req: Union[
+                pb2.AnalyzePlanRequest,
+                pb2.ConfigRequest,
+                pb2.ExecutePlanRequest,
+                pb2.FetchErrorDetailsRequest,
+                pb2.InterruptRequest,
+            ],
+        ) -> None:
+            with self.global_user_context_extensions_lock:
+                for _, extension in self.global_user_context_extensions:
+                    req.user_context.extensions.append(extension)
+            if not hasattr(self.thread_local, "user_context_extensions"):
+                return
+            for _, extension in self.thread_local.user_context_extensions:
+                req.user_context.extensions.append(extension)
+
     def _execute_plan_request_with_metadata(
         self, operation_id: Optional[str] = None
     ) -> pb2.ExecutePlanRequest:
@@ -1307,6 +1328,7 @@ def _execute_plan_request_with_metadata(
                     messageParameters={"arg_name": "operation_id", "origin": str(ve)},
                 )
             req.operation_id = operation_id
+        self._update_request_with_user_context_extensions(req)
         return req
 
     def _analyze_plan_request_with_metadata(self) -> pb2.AnalyzePlanRequest:
@@ -1317,6 +1339,7 @@ def _analyze_plan_request_with_metadata(self) -> pb2.AnalyzePlanRequest:
         req.client_type = self._builder.userAgent
         if self._user_id:
             req.user_context.user_id = self._user_id
+        self._update_request_with_user_context_extensions(req)
         return req
 
     def _analyze(self, method: str, **kwargs: Any) -> AnalyzeResult:
@@ -1731,6 +1754,7 @@ def _config_request_with_metadata(self) -> pb2.ConfigRequest:
         req.client_type = self._builder.userAgent
         if self._user_id:
             req.user_context.user_id = self._user_id
+        self._update_request_with_user_context_extensions(req)
         return req
 
     def get_configs(self, *keys: str) -> Tuple[Optional[str], ...]:
@@ -1807,6 +1831,7 @@ def _interrupt_request(
             )
         if self._user_id:
             req.user_context.user_id = self._user_id
+        self._update_request_with_user_context_extensions(req)
         return req
 
     def interrupt_all(self) -> Optional[List[str]]:
@@ -1905,6 +1930,38 @@ def _throw_if_invalid_tag(self, tag: str) -> None:
                 messageParameters={"arg_name": "Spark Connect tag", "arg_value": tag},
             )
 
+    def add_threadlocal_user_context_extension(self, extension: any_pb2.Any) -> str:
+        if not hasattr(self.thread_local, "user_context_extensions"):
+            self.thread_local.user_context_extensions = list()
+        extension_id = "threadlocal_" + str(uuid.uuid4())
+        self.thread_local.user_context_extensions.append((extension_id, extension))
+        return extension_id
+
+    def add_global_user_context_extension(self, extension: any_pb2.Any) -> str:
+        extension_id = "global_" + str(uuid.uuid4())
+        with self.global_user_context_extensions_lock:
+            self.global_user_context_extensions.append((extension_id, extension))
+        return extension_id
+
+    def remove_user_context_extension(self, extension_id: str) -> None:
+        if extension_id.find("threadlocal_") == 0:
+            if not hasattr(self.thread_local, "user_context_extensions"):
+                return
+            self.thread_local.user_context_extensions = list(
+                filter(lambda ex: ex[0] != extension_id, self.thread_local.user_context_extensions)
+            )
+        elif extension_id.find("global_") == 0:
+            with self.global_user_context_extensions_lock:
+                self.global_user_context_extensions = list(
+                    filter(lambda ex: ex[0] != extension_id, self.global_user_context_extensions)
+                )
+
+    def clear_user_context_extensions(self) -> None:
+        if hasattr(self.thread_local, "user_context_extensions"):
+            self.thread_local.user_context_extensions = list()
+        with self.global_user_context_extensions_lock:
+            self.global_user_context_extensions = list()
+
     def _handle_error(self, error: Exception) -> NoReturn:
         """
         Handle errors that occur during RPC calls.
@@ -1945,6 +2002,7 @@ def _fetch_enriched_error(self, info: "ErrorInfo") -> Optional[pb2.FetchErrorDet
             req.client_observed_server_side_session_id = self._server_session_id
         if self._user_id:
             req.user_context.user_id = self._user_id
+        self._update_request_with_user_context_extensions(req)
 
         try:
             return self._stub.FetchErrorDetails(req, metadata=self._builder.metadata())
diff --git a/python/pyspark/sql/tests/connect/client/test_client.py b/python/pyspark/sql/tests/connect/client/test_client.py
index c189f996cbe4..39abc769b673 100644
--- a/python/pyspark/sql/tests/connect/client/test_client.py
+++ b/python/pyspark/sql/tests/connect/client/test_client.py
@@ -26,6 +26,7 @@
 if should_test_connect:
     import grpc
     import google.protobuf.any_pb2 as any_pb2
+    import google.protobuf.wrappers_pb2 as wrappers_pb2
     from google.rpc import status_pb2
     from google.rpc.error_details_pb2 import ErrorInfo
     import pandas as pd