splitio · chillaq · Jan 27, 2026 · Jan 7, 2026 · Jan 8, 2026 · Jan 9, 2026
@@ -7,7 +7,7 @@
 from splitio.engine.evaluator import Evaluator, CONTROL, EvaluationDataFactory, AsyncEvaluationDataFactory
 from splitio.engine.splitters import Splitter
 from splitio.models.impressions import Impression, Label, ImpressionDecorated
-from splitio.models.events import Event, EventWrapper
+from splitio.models.events import Event, EventWrapper, SdkEvent
 from splitio.models.telemetry import get_latency_bucket_index, MethodExceptionsAndLatencies
 from splitio.client import input_validator
 from splitio.util.time import get_current_epoch_time_ms, utctime_ms
@@ -224,7 +224,7 @@ def _check_impression_label(self, result):
 class Client(ClientBase):  # pylint: disable=too-many-instance-attributes
     """Entry point for the split sdk."""
 
-    def __init__(self, factory, recorder, labels_enabled=True, fallback_treatment_calculator=None):
+    def __init__(self, factory, recorder, events_manager, labels_enabled=True, fallback_treatment_calculator=None):
         """
         Construct a Client instance.
 
@@ -240,6 +240,7 @@ def __init__(self, factory, recorder, labels_enabled=True, fallback_treatment_ca
         :rtype: Client
         """
         ClientBase.__init__(self, factory, recorder, labels_enabled, fallback_treatment_calculator)
+        self._events_manager = events_manager
         self._context_factory = EvaluationDataFactory(factory._get_storage('splits'), factory._get_storage('segments'), factory._get_storage('rule_based_segments'))
 
     def destroy(self):
@@ -249,7 +250,24 @@ def destroy(self):
         Only applicable when using in-memory operation mode.
         """
         self._factory.destroy()
+
+    def on(self, sdk_event, callback_handle):
+        if not self._validate_sdk_event_info(sdk_event, callback_handle):
+            return
+
+        self._events_manager.register(sdk_event, callback_handle)
 
+    def _validate_sdk_event_info(self, sdk_event, callback_handle):
+        if not isinstance(sdk_event, SdkEvent):
+            _LOGGER.warning("Client Event Subscription: The event passed must be of type SdkEvent, ignoring event subscribing action.")
+            return False
+
+        if not hasattr(callback_handle, '__call__'):
+            _LOGGER.warning("Client Event Subscription: The callback handle passed must be of type function, ignoring event subscribing action.")
+            return False
+
+        return True
+
     def get_treatment(self, key, feature_flag_name, attributes=None, evaluation_options=None):
         """
         Get the treatment for a feature flag and key, with an optional dictionary of attributes.

@@ -1,3 +1,4 @@
+import pytest
 """A module for Split.io Factories."""
 import logging
 import threading
@@ -19,8 +20,11 @@
     TelemetryStorageProducerAsync, TelemetryStorageConsumerAsync
 from splitio.engine.impressions.manager import Counter as ImpressionsCounter
 from splitio.engine.impressions.unique_keys_tracker import UniqueKeysTracker, UniqueKeysTrackerAsync
+from splitio.events.events_manager import EventsManager
+from splitio.events.events_manager_config import EventsManagerConfig
+from splitio.events.events_task import EventsTask
+from splitio.events.events_delivery import EventsDelivery
 from splitio.models.fallback_config import FallbackTreatmentCalculator
-from splitio.events.events_metadata import EventsMetadata, SdkEventType
 from splitio.models.notification import SdkInternalEventNotification
 from splitio.models.events import SdkInternalEvent
 
@@ -171,6 +175,7 @@ def __init__(  # pylint: disable=too-many-arguments
             labels_enabled,
             recorder,
             internal_events_queue,
+            events_manager,
             sync_manager=None,
             sdk_ready_flag=None,
             telemetry_producer=None,
@@ -210,6 +215,7 @@ def __init__(  # pylint: disable=too-many-arguments
         self._sdk_internal_ready_flag = sdk_ready_flag
         self._fallback_treatment_calculator = fallback_treatment_calculator
         self._internal_events_queue = internal_events_queue
+        self._events_manager = events_manager
         self._start_status_updater()
 
     def _start_status_updater(self):
@@ -254,7 +260,7 @@ def client(self):
         This client is only a set of references to structures hold by the factory.
         Creating one a fast operation and safe to be used anywhere.
         """
-        return Client(self, self._recorder, self._labels_enabled, self._fallback_treatment_calculator)
+        return Client(self, self._recorder, self._events_manager, self._labels_enabled, self._fallback_treatment_calculator)
 
     def manager(self):
         """
@@ -298,6 +304,7 @@ def destroy(self, destroyed_event=None):
 
         try:
             _LOGGER.info('Factory destroy called, stopping tasks.')
+            self._events_manager.destroy()
             if self._sync_manager is not None:
                 if destroyed_event is not None:
 
@@ -559,6 +566,8 @@ def _build_in_memory_factory(api_key, cfg, sdk_url=None, events_url=None,  # pyl
     }
 
     internal_events_queue = queue.Queue()
+    events_manager = EventsManager(EventsManagerConfig(), EventsDelivery())
+    internal_events_task = EventsTask(events_manager.notify_internal_event, internal_events_queue)
     storages = {
         'splits': InMemorySplitStorage(internal_events_queue, cfg['flagSetsFilter'] if cfg['flagSetsFilter'] is not None else []),
         'segments': InMemorySegmentStorage(internal_events_queue),
@@ -608,6 +617,7 @@ def _build_in_memory_factory(api_key, cfg, sdk_url=None, events_url=None,  # pyl
         TelemetrySyncTask(synchronizers.telemetry_sync.synchronize_stats, cfg['metricsRefreshRate']),
         unique_keys_task,
         clear_filter_task,
+        internal_events_task
     )
 
     synchronizer = Synchronizer(synchronizers, tasks)
@@ -639,14 +649,14 @@ def _build_in_memory_factory(api_key, cfg, sdk_url=None, events_url=None,  # pyl
         synchronizer._split_synchronizers._segment_sync.shutdown()
 
         return SplitFactory(api_key, storages, cfg['labelsEnabled'],
-                            recorder, internal_events_queue, manager, None, telemetry_producer, telemetry_init_producer, telemetry_submitter, preforked_initialization=preforked_initialization,
+                            recorder, internal_events_queue, events_manager, manager, None, telemetry_producer, telemetry_init_producer, telemetry_submitter, preforked_initialization=preforked_initialization,
                             fallback_treatment_calculator=FallbackTreatmentCalculator(cfg['fallbackTreatments']))
 
     initialization_thread = threading.Thread(target=manager.start, name="SDKInitializer", daemon=True)
     initialization_thread.start()
 
     return SplitFactory(api_key, storages, cfg['labelsEnabled'],
-                        recorder, internal_events_queue, manager, sdk_ready_flag,
+                        recorder, internal_events_queue, events_manager, manager, sdk_ready_flag,
                         telemetry_producer, telemetry_init_producer,
                         telemetry_submitter, fallback_treatment_calculator = FallbackTreatmentCalculator(cfg['fallbackTreatments']))
 
@@ -837,13 +847,15 @@ def _build_redis_factory(api_key, cfg):
 
     telemetry_init_producer.record_config(cfg, {}, 0, 0)
     internal_events_queue = queue.Queue()
-
+    events_manager = EventsManager(EventsManagerConfig(), EventsDelivery())
+
     split_factory = SplitFactory(
         api_key,
         storages,
         cfg['labelsEnabled'],
         recorder,
         internal_events_queue,
+        events_manager,
         manager,
         sdk_ready_flag=None,
         telemetry_producer=telemetry_producer,
@@ -1005,13 +1017,15 @@ def _build_pluggable_factory(api_key, cfg):
 
     telemetry_init_producer.record_config(cfg, {}, 0, 0)
     internal_events_queue = queue.Queue()
+    events_manager = EventsManager(EventsManagerConfig(), EventsDelivery())
 
     split_factory = SplitFactory(
         api_key,
         storages,
         cfg['labelsEnabled'],
         recorder,
         internal_events_queue,
+        events_manager,
         manager,
         sdk_ready_flag=None,
         telemetry_producer=telemetry_producer,
@@ -1167,13 +1181,15 @@ def _build_localhost_factory(cfg):
         telemetry_runtime_producer
     )
     internal_events_queue = queue.Queue()
-
+    events_manager = EventsManager(EventsManagerConfig(), EventsDelivery())
+
     return SplitFactory(
         'localhost',
         storages,
         False,
         recorder,
         internal_events_queue,
+        events_manager,
         manager,
         ready_event,
         telemetry_producer=telemetry_producer,
@@ -1259,13 +1275,14 @@ def get_factory(api_key, **kwargs):
     _INSTANTIATED_FACTORIES_LOCK.acquire()
     if _INSTANTIATED_FACTORIES:
         if api_key in _INSTANTIATED_FACTORIES:
-            _LOGGER.warning(
-                "factory instantiation: You already have %d %s with this SDK Key. "
-                "We recommend keeping only one instance of the factory at all times "
-                "(Singleton pattern) and reusing it throughout your application.",
-                _INSTANTIATED_FACTORIES[api_key],
-                'factory' if _INSTANTIATED_FACTORIES[api_key] == 1 else 'factories'
-            )
+            if _INSTANTIATED_FACTORIES[api_key] > 0:
+                _LOGGER.warning(
+                    "factory instantiation: You already have %d %s with this SDK Key. "
+                    "We recommend keeping only one instance of the factory at all times "
+                    "(Singleton pattern) and reusing it throughout your application.",
+                    _INSTANTIATED_FACTORIES[api_key],
+                    'factory' if _INSTANTIATED_FACTORIES[api_key] == 1 else 'factories'
+                )
         else:
             _LOGGER.warning(
                 "factory instantiation: You already have an instance of the Split factory. "

@@ -49,6 +49,11 @@ def notify_internal_event(self, sdk_internal_event, event_metadata):
                         notify_event.start()
                         self._set_sdk_event_triggered(sorted_event)
 
+    def destroy(self):
+        with self._lock:
+            self._active_subscriptions = {}
+            self._internal_events_status = {}
+
     def _event_already_triggered(self, sdk_event):
         if self._active_subscriptions.get(sdk_event) != None:
             return self._active_subscriptions.get(sdk_event).triggered

@@ -64,19 +64,20 @@ def _run(self):
     def start(self):
         """Start worker."""
         if self.is_running():
-            _LOGGER.debug('Worker is already running')
+            _LOGGER.debug('SDK Event Worker is already running')
             return
+
         self._running = True
-
-        _LOGGER.debug('Starting Event Task worker')
+        _LOGGER.debug('Starting SDK Event Task worker')
         self._worker = threading.Thread(target=self._run, name='EventsTaskWorker', daemon=True)
         self._worker.start()
 
-    def stop(self):
+    def stop(self, stop_flag=None):
         """Stop worker."""
-        _LOGGER.debug('Stopping Event Task worker')
+        _LOGGER.debug('Stopping SDK Event Task worker')
         if not self.is_running():
-            _LOGGER.debug('Worker is not running. Ignoring.')
+            _LOGGER.debug('SDK Event Worker is not running. Ignoring.')
             return
+
         self._running = False
         self._internal_events_queue.put(self._centinel)
@@ -90,7 +90,7 @@ class SplitTasks(object):
     """SplitTasks."""
 
     def __init__(self, feature_flag_task, segment_task, impressions_task, events_task,  # pylint:disable=too-many-arguments
-                 impressions_count_task, telemetry_task=None, unique_keys_task = None, clear_filter_task = None):
+                 impressions_count_task, telemetry_task=None, unique_keys_task = None, clear_filter_task = None, internal_events_task=None):
         """
         Class constructor.
 
@@ -113,6 +113,7 @@ def __init__(self, feature_flag_task, segment_task, impressions_task, events_tas
         self._unique_keys_task = unique_keys_task
         self._clear_filter_task = clear_filter_task
         self._telemetry_task = telemetry_task
+        self._internal_events_task = internal_events_task
 
     @property
     def split_task(self):
@@ -154,6 +155,11 @@ def telemetry_task(self):
         """Return clear filter sync task."""
         return self._telemetry_task
 
+    @property
+    def internal_events_task(self):
+        """Return internal events task."""
+        return self._internal_events_task
+
 class BaseSynchronizer(object, metaclass=abc.ABCMeta):
     """Synchronizer interface."""
 
@@ -323,6 +329,9 @@ def start_periodic_data_recording(self):
         for task in self._periodic_data_recording_tasks:
             task.start()
 
+        if self._split_tasks.internal_events_task:
+            self._split_tasks.internal_events_task.start()
+
     def stop_periodic_data_recording(self, blocking):
         """
         Stop recorders.
@@ -477,6 +486,9 @@ def stop_periodic_data_recording(self, blocking):
         :type blocking: bool
         """
         _LOGGER.debug('Stopping periodic data recording')
+        if self._split_tasks.internal_events_task:
+            self._split_tasks.internal_events_task.stop()
+
         if blocking:
             events = []
             for task in self._periodic_data_recording_tasks:
@@ -871,6 +883,8 @@ def start_periodic_fetching(self):
             self._split_tasks.split_task.start()
         if self._split_tasks.segment_task is not None:
             self._split_tasks.segment_task.start()
+        if self._split_tasks.internal_events_task:
+            self._split_tasks.internal_events_task.start()
 
     def stop_periodic_fetching(self):
         """Stop fetchers for feature flags and segments."""
@@ -948,6 +962,8 @@ def stop_periodic_fetching(self):
             self._split_tasks.split_task.stop()
         if self._split_tasks.segment_task is not None:
             self._split_tasks.segment_task.stop()
+        if self._split_tasks.internal_events_task:
+            self._split_tasks.internal_events_task.stop()
 
     def synchronize_splits(self):
         """Synchronize all feature flags."""