Add experimental activity sessions and worker session options

changelog/added/humming-sticky-teapot.md

@@ -0,0 +1 @@
+Added experimental workflow-affine activities through `workflow.ActivitySessionOptions.workflow_session()` and `worker.WorkerSessionOptions`, with optional `worker.SingleSessionOptions` for lifetime dedication to a stable destination.

changelog/added/unmanipulative-ettie.md

@@ -0,0 +1,2 @@
+Core: Experimental session workers can poll workflow-affine activity queues; individual activities opt into their workflow's session, while normal activity routing remains the default. This increment supports fixed-size activity slots with capacity of at least two; resource-based and custom activity suppliers are not supported yet. Activity session options must select workflow-session routing; empty options or an explicit false selection are rejected.
+Core: Experimental worker session options support a single-session policy with a stable destination, dedicating that destination to the first matched workflow for its lifetime with a supporting server. Sticky-only mode may use one fixed activity slot.

changelog/added/unpimpled-flora.md

@@ -0,0 +1 @@
+Core: The OTLP metrics exporter can export histograms as OpenTelemetry exponential histograms, which Prometheus-compatible backends store as native histograms, when an SDK enables the option, including through the C bridge. It applies to every histogram, including custom ones, and names each series with a suffix, `_native` by default, so it never shares a name with the fixed-bucket series it replaces. It cannot be combined with histogram bucket overrides. Explicit buckets remain the default.

changelog/fixed/unmanipulative-ettie.md

@@ -0,0 +1 @@
+Core: Session workers drain both activity poll sources during graceful shutdown, avoiding abandoned deliveries when one source finishes before the other.

changelog/fixed/unpimpled-flora.md

@@ -0,0 +1 @@
+Core: Workers now replay workflows paused before a scheduled task starts, allowing those workflows to make progress after unpause.

changelog/security/unpimpled-flora.md

@@ -0,0 +1 @@
+Core: Ephemeral server downloads now use `zip` 9.0 for ZIP extraction, replacing the 8.x dependency [yanked upstream for security issues](https://github.com/zip-rs/zip2/issues/1075#issuecomment-6209381974).

temporalio/api/command/v1/message_pb2.pyi

@@ -18,6 +18,7 @@ import temporalio.api.enums.v1.workflow_pb2
 import temporalio.api.failure.v1.message_pb2
 import temporalio.api.sdk.v1.event_group_marker_pb2
 import temporalio.api.sdk.v1.user_metadata_pb2
+import temporalio.api.session.v1.message_pb2
 import temporalio.api.taskqueue.v1.message_pb2
 import temporalio.api.workflow.v1.message_pb2
 
@@ -44,6 +45,7 @@ class ScheduleActivityTaskCommandAttributes(google.protobuf.message.Message):
     REQUEST_EAGER_EXECUTION_FIELD_NUMBER: builtins.int
     USE_WORKFLOW_BUILD_ID_FIELD_NUMBER: builtins.int
     PRIORITY_FIELD_NUMBER: builtins.int
+    SESSION_OPTIONS_FIELD_NUMBER: builtins.int
     activity_id: builtins.str
     @property
     def activity_type(self) -> temporalio.api.common.v1.message_pb2.ActivityType: ...
@@ -106,6 +108,10 @@ class ScheduleActivityTaskCommandAttributes(google.protobuf.message.Message):
         """Priority metadata. If this message is not present, or any fields are not
         present, they inherit the values from the workflow.
         """
+    @property
+    def session_options(
+        self,
+    ) -> temporalio.api.session.v1.message_pb2.ActivitySessionOptions: ...
     def __init__(
         self,
         *,
@@ -122,6 +128,8 @@ class ScheduleActivityTaskCommandAttributes(google.protobuf.message.Message):
         request_eager_execution: builtins.bool = ...,
         use_workflow_build_id: builtins.bool = ...,
         priority: temporalio.api.common.v1.message_pb2.Priority | None = ...,
+        session_options: temporalio.api.session.v1.message_pb2.ActivitySessionOptions
+        | None = ...,
     ) -> None: ...
     def HasField(
         self,
@@ -142,6 +150,8 @@ class ScheduleActivityTaskCommandAttributes(google.protobuf.message.Message):
             b"schedule_to_close_timeout",
             "schedule_to_start_timeout",
             b"schedule_to_start_timeout",
+            "session_options",
+            b"session_options",
             "start_to_close_timeout",
             b"start_to_close_timeout",
             "task_queue",
@@ -171,6 +181,8 @@ class ScheduleActivityTaskCommandAttributes(google.protobuf.message.Message):
             b"schedule_to_close_timeout",
             "schedule_to_start_timeout",
             b"schedule_to_start_timeout",
+            "session_options",
+            b"session_options",
             "start_to_close_timeout",
             b"start_to_close_timeout",
             "task_queue",

temporalio/api/history/v1/message_pb2.pyi

@@ -24,6 +24,7 @@ import temporalio.api.nexus.v1.message_pb2
 import temporalio.api.sdk.v1.event_group_marker_pb2
 import temporalio.api.sdk.v1.task_complete_metadata_pb2
 import temporalio.api.sdk.v1.user_metadata_pb2
+import temporalio.api.session.v1.message_pb2
 import temporalio.api.taskqueue.v1.message_pb2
 import temporalio.api.update.v1.message_pb2
 import temporalio.api.workflow.v1.message_pb2
@@ -1290,6 +1291,7 @@ class ActivityTaskScheduledEventAttributes(google.protobuf.message.Message):
     RETRY_POLICY_FIELD_NUMBER: builtins.int
     USE_WORKFLOW_BUILD_ID_FIELD_NUMBER: builtins.int
     PRIORITY_FIELD_NUMBER: builtins.int
+    SESSION_OPTIONS_FIELD_NUMBER: builtins.int
     activity_id: builtins.str
     """The worker/user assigned identifier for the activity"""
     @property
@@ -1348,6 +1350,13 @@ class ActivityTaskScheduledEventAttributes(google.protobuf.message.Message):
         """Priority metadata. If this message is not present, or any fields are not
         present, they inherit the values from the workflow.
         """
+    @property
+    def session_options(
+        self,
+    ) -> temporalio.api.session.v1.message_pb2.ActivitySessionOptions:
+        """Preserves the scheduling command's session routing options so activity state
+        can be reconstructed from history.
+        """
     def __init__(
         self,
         *,
@@ -1364,6 +1373,8 @@ class ActivityTaskScheduledEventAttributes(google.protobuf.message.Message):
         retry_policy: temporalio.api.common.v1.message_pb2.RetryPolicy | None = ...,
         use_workflow_build_id: builtins.bool = ...,
         priority: temporalio.api.common.v1.message_pb2.Priority | None = ...,
+        session_options: temporalio.api.session.v1.message_pb2.ActivitySessionOptions
+        | None = ...,
     ) -> None: ...
     def HasField(
         self,
@@ -1384,6 +1395,8 @@ class ActivityTaskScheduledEventAttributes(google.protobuf.message.Message):
             b"schedule_to_close_timeout",
             "schedule_to_start_timeout",
             b"schedule_to_start_timeout",
+            "session_options",
+            b"session_options",
             "start_to_close_timeout",
             b"start_to_close_timeout",
             "task_queue",
@@ -1411,6 +1424,8 @@ class ActivityTaskScheduledEventAttributes(google.protobuf.message.Message):
             b"schedule_to_close_timeout",
             "schedule_to_start_timeout",
             b"schedule_to_start_timeout",
+            "session_options",
+            b"session_options",
             "start_to_close_timeout",
             b"start_to_close_timeout",
             "task_queue",