diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/_model_utils.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/_model_utils.py
index b747c8ed..342d4572 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/_model_utils.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/_model_utils.py
@@ -2,10 +2,11 @@
 # Licensed under the MIT License.
 
 from abc import ABC
-from typing import Any, Callable
+from typing import Any, Callable, TypeVar
 
 from .agents_model import AgentsModel
 
+AgentsModelT = TypeVar("AgentsModelT", bound=AgentsModel)
 
 class ModelFieldHelper(ABC):
     """Base class for model field processing prior to initialization of an AgentsModel"""
@@ -54,8 +55,7 @@ def pick_model_dict(**kwargs):
 
     return model_dict
 
-
-def pick_model(model_class: type[AgentsModel], **kwargs) -> AgentsModel:
+def pick_model(model_class: type[AgentsModelT], **kwargs) -> AgentsModelT:
     """Picks model fields from the given keyword arguments.
 
     Usage:
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/activity.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/activity.py
index c3881d30..68eeb9bb 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/activity.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/activity.py
@@ -6,7 +6,7 @@
 import logging
 from copy import copy
 from datetime import datetime, timezone
-from typing import Optional, Any, cast, Annotated, TypeVar
+from typing import Optional, Any, cast, Annotated, TypeVar, TYPE_CHECKING
 from typing_extensions import Self
 
 from pydantic import (
@@ -54,105 +54,7 @@
 
 # TODO: A2A Agent 2 is responding with None as id, had to mark it as optional (investigate)
 class Activity(AgentsModel, _ChannelIdFieldMixin):
-    """An Activity is the basic communication type for the protocol.
-
-    :param type: Contains the activity type. Possible values include:
-        'message', 'contactRelationUpdate', 'conversationUpdate', 'typing',
-        'endOfConversation', 'event', 'invoke', 'deleteUserData', 'messageUpdate',
-        'messageDelete', 'installationUpdate', 'messageReaction', 'suggestion',
-        'trace', 'handoff'
-    :type type: str or ~microsoft_agents.activity.ActivityTypes
-    :param id: Contains an ID that uniquely identifies the activity on the channel.
-    :type id: str
-    :param timestamp: Contains the date and time that the message was sent, in UTC, expressed in ISO-8601 format.
-    :type timestamp: datetime
-    :param local_timestamp: Contains the local date and time of the message expressed in ISO-8601 format.
-        For example, 2016-09-23T13:07:49.4714686-07:00.
-    :type local_timestamp: datetime
-    :param local_timezone: Contains the name of the local timezone of the message, expressed in IANA Time Zone database format.
-        For example, America/Los_Angeles.
-    :type local_timezone: str
-    :param service_url: Contains the URL that specifies the channel's service endpoint. Set by the channel.
-    :type service_url: str
-    :param channel_id: Contains an ID that uniquely identifies the channel (and possibly the sub-channel). Set by the channel.
-    :type channel_id: ~microsoft_agents.activity.ChannelId
-    :param from_property: Identifies the sender of the message.
-    :type from_property: ~microsoft_agents.activity.ChannelAccount
-    :param conversation: Identifies the conversation to which the activity belongs.
-    :type conversation: ~microsoft_agents.activity.ConversationAccount
-    :param recipient: Identifies the recipient of the message.
-    :type recipient: ~microsoft_agents.activity.ChannelAccount
-    :param text_format: Format of text fields Default:markdown. Possible values include: 'markdown', 'plain', 'xml'
-    :type text_format: str or ~microsoft_agents.activity.TextFormatTypes
-    :param attachment_layout: The layout hint for multiple attachments. Default: list. Possible values include: 'list', 'carousel'
-    :type attachment_layout: str or ~microsoft_agents.activity.AttachmentLayoutTypes
-    :param members_added: The collection of members added to the conversation.
-    :type members_added: list[~microsoft_agents.activity.ChannelAccount]
-    :param members_removed: The collection of members removed from the conversation.
-    :type members_removed: list[~microsoft_agents.activity.ChannelAccount]
-    :param reactions_added: The collection of reactions added to the conversation.
-    :type reactions_added: list[~microsoft_agents.activity.MessageReaction]
-    :param reactions_removed: The collection of reactions removed from the conversation.
-    :type reactions_removed: list[~microsoft_agents.activity.MessageReaction]
-    :param topic_name: The updated topic name of the conversation.
-    :type topic_name: str
-    :param history_disclosed: Indicates whether the prior history of the channel is disclosed.
-    :type history_disclosed: bool
-    :param locale: A locale name for the contents of the text field. The locale name is a combination of an ISO 639 two- or three-letter
-        culture code associated with a language and an ISO 3166 two-letter subculture code associated with a country or region.
-        The locale name can also correspond to a valid BCP-47 language tag.
-    :type locale: str
-    :param text: The text content of the message.
-    :type text: str
-    :param speak: The text to speak.
-    :type speak: str
-    :param input_hint: Indicates whether your agent is accepting, expecting, or ignoring user input after the message is delivered to the client.
-        Possible values include: 'acceptingInput', 'ignoringInput', 'expectingInput'
-    :type input_hint: str or ~microsoft_agents.activity.InputHints
-    :param summary: The text to display if the channel cannot render cards.
-    :type summary: str
-    :param suggested_actions: The suggested actions for the activity.
-    :type suggested_actions: ~microsoft_agents.activity.SuggestedActions
-    :param attachments: Attachments
-    :type attachments: list[~microsoft_agents.activity.Attachment]
-    :param entities: Represents the entities that were mentioned in the message.
-    :type entities: list[~microsoft_agents.activity.Entity]
-    :param channel_data: Contains channel-specific content.
-    :type channel_data: object
-    :param action: Indicates whether the recipient of a contactRelationUpdate was added or removed from the sender's contact list.
-    :type action: str
-    :param reply_to_id: Contains the ID of the message to which this message is a reply.
-    :type reply_to_id: str
-    :param label: A descriptive label for the activity.
-    :type label: str
-    :param value_type: The type of the activity's value object.
-    :type value_type: str
-    :param value: A value that is associated with the activity.
-    :type value: object
-    :param name: The name of the operation associated with an invoke or event activity.
-    :type name: str
-    :param relates_to: A reference to another conversation or activity.
-    :type relates_to: ~microsoft_agents.activity.ConversationReference
-    :param code: The a code for endOfConversation activities that indicates why the conversation ended. Possible values include: 'unknown',
-        'completedSuccessfully', 'userCancelled', 'botTimedOut', 'botIssuedInvalidMessage', 'channelFailed'
-    :type code: str or ~microsoft_agents.activity.EndOfConversationCodes
-    :param expiration: The time at which the activity should be considered to be "expired" and should not be presented to the recipient.
-    :type expiration: datetime
-    :param importance: The importance of the activity. Possible values include: 'low', 'normal', 'high'
-    :type importance: str or ~microsoft_agents.activity.ActivityImportance
-    :param delivery_mode: A delivery hint to signal to the recipient alternate delivery paths for the activity.
-        The default delivery mode is "default". Possible values include: 'normal', 'notification', 'expectReplies', 'ephemeral'
-    :type delivery_mode: str or ~microsoft_agents.activity.DeliveryModes
-    :param listen_for: List of phrases and references that speech and language priming systems should listen for
-    :type listen_for: list[str]
-    :param text_highlights: The collection of text fragments to highlight when the activity contains a ReplyToId value.
-    :type text_highlights: list[~microsoft_agents.activity.TextHighlight]
-    :param semantic_action: An optional programmatic action accompanying this request
-    :type semantic_action: ~microsoft_agents.activity.SemanticAction
-    :param caller_id: A string containing an IRI identifying the caller of an agent. This field is not intended to be transmitted over the wire,
-        but is instead populated by agents and clients based on cryptographically verifiable data that asserts the identity of the callers (e.g. tokens).
-    :type caller_id: str
-    """
+    """An Activity is the basic communication type for the protocol."""
 
     type: NonEmptyString
     id: Optional[NonEmptyString] = None
@@ -196,6 +98,115 @@ class Activity(AgentsModel, _ChannelIdFieldMixin):
     semantic_action: SemanticAction = None
     caller_id: NonEmptyString = None
 
+    # def __init__(self, channel_id: str | ChannelId | None = None, *args, **kwargs):
+    #     kwargs["channel_id"] = channel_id
+    #     super().__init__(*args, **kwargs)
+
+    if TYPE_CHECKING:
+        def __init__(self,
+            *,
+            channel_id: ChannelId | str | None = None,
+            **kwargs) -> None:
+            """Initialize an Activity instance.
+            
+            :param type: Contains the activity type. Possible values include:
+                'message', 'contactRelationUpdate', 'conversationUpdate', 'typing',
+                'endOfConversation', 'event', 'invoke', 'deleteUserData', 'messageUpdate',
+                'messageDelete', 'installationUpdate', 'messageReaction', 'suggestion',
+                'trace', 'handoff'
+            :type type: str or ~microsoft_agents.activity.ActivityTypes
+            :param id: Contains an ID that uniquely identifies the activity on the channel.
+            :type id: str
+            :param timestamp: Contains the date and time that the message was sent, in UTC, expressed in ISO-8601 format.
+            :type timestamp: datetime
+            :param local_timestamp: Contains the local date and time of the message expressed in ISO-8601 format.
+                For example, 2016-09-23T13:07:49.4714686-07:00.
+            :type local_timestamp: datetime
+            :param local_timezone: Contains the name of the local timezone of the message, expressed in IANA Time Zone database format.
+                For example, America/Los_Angeles.
+            :type local_timezone: str
+            :param service_url: Contains the URL that specifies the channel's service endpoint. Set by the channel.
+            :type service_url: str
+            :param channel_id: Contains an ID that uniquely identifies the channel (and possibly the sub-channel). Set by the channel.
+            :type channel_id: ~microsoft_agents.activity.ChannelId
+            :param from_property: Identifies the sender of the message.
+            :type from_property: ~microsoft_agents.activity.ChannelAccount
+            :param conversation: Identifies the conversation to which the activity belongs.
+            :type conversation: ~microsoft_agents.activity.ConversationAccount
+            :param recipient: Identifies the recipient of the message.
+            :type recipient: ~microsoft_agents.activity.ChannelAccount
+            :param text_format: Format of text fields Default:markdown. Possible values include: 'markdown', 'plain', 'xml'
+            :type text_format: str or ~microsoft_agents.activity.TextFormatTypes
+            :param attachment_layout: The layout hint for multiple attachments. Default: list. Possible values include: 'list', 'carousel'
+            :type attachment_layout: str or ~microsoft_agents.activity.AttachmentLayoutTypes
+            :param members_added: The collection of members added to the conversation.
+            :type members_added: list[~microsoft_agents.activity.ChannelAccount]
+            :param members_removed: The collection of members removed from the conversation.
+            :type members_removed: list[~microsoft_agents.activity.ChannelAccount]
+            :param reactions_added: The collection of reactions added to the conversation.
+            :type reactions_added: list[~microsoft_agents.activity.MessageReaction]
+            :param reactions_removed: The collection of reactions removed from the conversation.
+            :type reactions_removed: list[~microsoft_agents.activity.MessageReaction]
+            :param topic_name: The updated topic name of the conversation.
+            :type topic_name: str
+            :param history_disclosed: Indicates whether the prior history of the channel is disclosed.
+            :type history_disclosed: bool
+            :param locale: A locale name for the contents of the text field. The locale name is a combination of an ISO 639 two- or three-letter
+                culture code associated with a language and an ISO 3166 two-letter subculture code associated with a country or region.
+                The locale name can also correspond to a valid BCP-47 language tag.
+            :type locale: str
+            :param text: The text content of the message.
+            :type text: str
+            :param speak: The text to speak.
+            :type speak: str
+            :param input_hint: Indicates whether your agent is accepting, expecting, or ignoring user input after the message is delivered to the client.
+                Possible values include: 'acceptingInput', 'ignoringInput', 'expectingInput'
+            :type input_hint: str or ~microsoft_agents.activity.InputHints
+            :param summary: The text to display if the channel cannot render cards.
+            :type summary: str
+            :param suggested_actions: The suggested actions for the activity.
+            :type suggested_actions: ~microsoft_agents.activity.SuggestedActions
+            :param attachments: Attachments
+            :type attachments: list[~microsoft_agents.activity.Attachment]
+            :param entities: Represents the entities that were mentioned in the message.
+            :type entities: list[~microsoft_agents.activity.Entity]
+            :param channel_data: Contains channel-specific content.
+            :type channel_data: object
+            :param action: Indicates whether the recipient of a contactRelationUpdate was added or removed from the sender's contact list.
+            :type action: str
+            :param reply_to_id: Contains the ID of the message to which this message is a reply.
+            :type reply_to_id: str
+            :param label: A descriptive label for the activity.
+            :type label: str
+            :param value_type: The type of the activity's value object.
+            :type value_type: str
+            :param value: A value that is associated with the activity.
+            :type value: object
+            :param name: The name of the operation associated with an invoke or event activity.
+            :type name: str
+            :param relates_to: A reference to another conversation or activity.
+            :type relates_to: ~microsoft_agents.activity.ConversationReference
+            :param code: The a code for endOfConversation activities that indicates why the conversation ended. Possible values include: 'unknown',
+                'completedSuccessfully', 'userCancelled', 'botTimedOut', 'botIssuedInvalidMessage', 'channelFailed'
+            :type code: str or ~microsoft_agents.activity.EndOfConversationCodes
+            :param expiration: The time at which the activity should be considered to be "expired" and should not be presented to the recipient.
+            :type expiration: datetime
+            :param importance: The importance of the activity. Possible values include: 'low', 'normal', 'high'
+            :type importance: str or ~microsoft_agents.activity.ActivityImportance
+            :param delivery_mode: A delivery hint to signal to the recipient alternate delivery paths for the activity.
+                The default delivery mode is "default". Possible values include: 'normal', 'notification', 'expectReplies', 'ephemeral'
+            :type delivery_mode: str or ~microsoft_agents.activity.DeliveryModes
+            :param listen_for: List of phrases and references that speech and language priming systems should listen for
+            :type listen_for: list[str]
+            :param text_highlights: The collection of text fragments to highlight when the activity contains a ReplyToId value.
+            :type text_highlights: list[~microsoft_agents.activity.TextHighlight]
+            :param semantic_action: An optional programmatic action accompanying this request
+            :type semantic_action: ~microsoft_agents.activity.SemanticAction
+            :param caller_id: A string containing an IRI identifying the caller of an agent. This field is not intended to be transmitted over the wire,
+                but is instead populated by agents and clients based on cryptographically verifiable data that asserts the identity of the callers (e.g. tokens).
+            :type caller_id: str
+            """
+
     @model_validator(mode="wrap")
     @classmethod
     def _validate_channel_id(
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/channel_id.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/channel_id.py
index e8192d6c..406ebd44 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/channel_id.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/channel_id.py
@@ -3,7 +3,7 @@
 
 from __future__ import annotations
 
-from typing import Optional, Any
+from typing import Any
 
 from pydantic_core import CoreSchema, core_schema
 from pydantic import GetCoreSchemaHandler
@@ -16,10 +16,10 @@ class ChannelId(str):
 
     def __init__(
         self,
-        value: Optional[str] = None,
+        value: str | None = None,
         *,
-        channel: Optional[str] = None,
-        sub_channel: Optional[str] = None,
+        channel: str | None = None,
+        sub_channel: str | None = None,
     ) -> None:
         """Initialize a ChannelId instance.
 
@@ -39,10 +39,10 @@ def __init__(
 
     def __new__(
         cls,
-        value: Optional[str] = None,
+        value: str | None = None,
         *,
-        channel: Optional[str] = None,
-        sub_channel: Optional[str] = None,
+        channel: str | None = None,
+        sub_channel: str | None = None,
     ) -> ChannelId:
         """Create a new ChannelId instance.
 
@@ -83,7 +83,7 @@ def channel(self) -> str:
         return self._channel  # type: ignore[return-value]
 
     @property
-    def sub_channel(self) -> Optional[str]:
+    def sub_channel(self) -> str | None:
         """The sub-channel, e.g. 'work' in 'email:work'. May be None."""
         return self._sub_channel
 
@@ -93,3 +93,21 @@ def __get_pydantic_core_schema__(
         cls, source_type: Any, handler: GetCoreSchemaHandler
     ) -> CoreSchema:
         return core_schema.no_info_after_validator_function(cls, handler(str))
+
+    @staticmethod
+    def get_channel(s: str | ChannelId) -> str:
+        """Return the main channel from a ChannelId string."""
+        if not s:
+            return s
+        if isinstance(s, ChannelId):
+            return s.channel
+        return ChannelId(s).channel
+    
+    @staticmethod
+    def get_sub_channel(s: str | ChannelId) -> str | None:
+        """Return the sub-channel from a ChannelId string."""
+        if not s:
+            return None
+        if isinstance(s, ChannelId):
+            return s.sub_channel
+        return ChannelId(s).sub_channel
\ No newline at end of file
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/channels.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/channels.py
index f94e7fe1..7abcc130 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/channels.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/channels.py
@@ -2,7 +2,8 @@
 # Licensed under the MIT License.
 
 from enum import Enum
-from typing_extensions import Self
+
+from .channel_id import ChannelId
 
 
 class Channels(str, Enum):
@@ -70,9 +71,8 @@ class Channels(str, Enum):
     copilot_studio = "pva-studio"
     """Microsoft Copilot Studio channel."""
 
-    # TODO: validate the need of Self annotations in the following methods
     @staticmethod
-    def supports_suggested_actions(channel_id: Self, button_cnt: int = 100) -> bool:
+    def supports_suggested_actions(channel_id: str | ChannelId, button_count: int = 100) -> bool:
         """Determine if a number of Suggested Actions are supported by a Channel.
 
         Args:
@@ -83,29 +83,30 @@ def supports_suggested_actions(channel_id: Self, button_cnt: int = 100) -> bool:
             bool: True if the Channel supports the button_cnt total Suggested Actions, False if the Channel does not
              support that number of Suggested Actions.
         """
+        channel = ChannelId.get_channel(channel_id)
 
         max_actions = {
             # https://developers.facebook.com/docs/messenger-platform/send-messages/quick-replies
-            Channels.facebook: 10,
-            Channels.skype: 10,
+            Channels.facebook.value: 10,
+            Channels.skype.value: 10,
             # https://developers.line.biz/en/reference/messaging-api/#items-object
-            Channels.line: 13,
+            Channels.line.value: 13,
             # https://dev.kik.com/#/docs/messaging#text-response-object
-            Channels.kik: 20,
-            Channels.telegram: 100,
-            Channels.emulator: 100,
-            Channels.direct_line: 100,
-            Channels.direct_line_speech: 100,
-            Channels.webchat: 100,
+            Channels.kik.value: 20,
+            Channels.telegram.value: 100,
+            Channels.emulator.value: 100,
+            Channels.direct_line.value: 100,
+            Channels.direct_line_speech.value: 100,
+            Channels.webchat.value: 100,
         }
         return (
-            button_cnt <= max_actions[channel_id]
+            button_count <= max_actions[channel]
             if channel_id in max_actions
             else False
         )
 
     @staticmethod
-    def supports_card_actions(channel_id: Self, button_cnt: int = 100) -> bool:
+    def supports_card_actions(channel_id: str | ChannelId, button_count: int = 100) -> bool:
         """Determine if a number of Card Actions are supported by a Channel.
 
         Args:
@@ -117,21 +118,23 @@ def supports_card_actions(channel_id: Self, button_cnt: int = 100) -> bool:
              that number of Card Actions.
         """
 
+        channel = ChannelId.get_channel(channel_id)
+
         max_actions = {
-            Channels.facebook: 3,
-            Channels.skype: 3,
-            Channels.ms_teams: 3,
-            Channels.line: 99,
-            Channels.slack: 100,
-            Channels.telegram: 100,
-            Channels.emulator: 100,
-            Channels.direct_line: 100,
-            Channels.direct_line_speech: 100,
-            Channels.webchat: 100,
+            Channels.facebook.value: 3,
+            Channels.skype.value: 3,
+            Channels.ms_teams.value: 3,
+            Channels.line.value: 99,
+            Channels.slack.value: 100,
+            Channels.telegram.value: 100,
+            Channels.emulator.value: 100,
+            Channels.direct_line.value: 100,
+            Channels.direct_line_speech.value: 100,
+            Channels.webchat.value: 100,
         }
         return (
-            button_cnt <= max_actions[channel_id]
-            if channel_id in max_actions
+            button_count <= max_actions[channel]
+            if channel in max_actions
             else False
         )
 
@@ -150,15 +153,14 @@ def has_message_feed(_: str) -> bool:
 
     @staticmethod
     def max_action_title_length(  # pylint: disable=unused-argument
-        channel_id: Self,
+        channel_id: str | ChannelId,
     ) -> int:
         """Maximum length allowed for Action Titles.
 
         Args:
-            channel_id (str): The Channel to determine Maximum Action Title Length.
+            channel_id (str | ChannelId): The Channel to determine Maximum Action Title Length.
 
         Returns:
             int: The total number of characters allowed for an Action Title on a specific Channel.
         """
-
         return 20
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_parameters.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_parameters.py
index 747e7814..07eeb55e 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_parameters.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_parameters.py
@@ -7,6 +7,7 @@
 from .activity import Activity
 from .agents_model import AgentsModel
 from ._type_aliases import NonEmptyString
+from .conversation_account import ConversationAccount
 
 
 class ConversationParameters(AgentsModel):
@@ -38,3 +39,4 @@ class ConversationParameters(AgentsModel):
     activity: Activity = None
     channel_data: object = None
     tenant_id: NonEmptyString = None
+    conversation: ConversationAccount | None = None
\ No newline at end of file
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_reference.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_reference.py
index cde7b100..9f4e3ed4 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_reference.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/conversation_reference.py
@@ -4,10 +4,11 @@
 from __future__ import annotations
 
 from uuid import uuid4 as uuid
-from typing import Optional, Annotated
+from typing import Optional, Annotated, TYPE_CHECKING
 
 from pydantic import Field
 
+from .channel_id import ChannelId
 from .channel_account import ChannelAccount
 from ._channel_id_field_mixin import _ChannelIdFieldMixin
 from .conversation_account import ConversationAccount
@@ -16,30 +17,12 @@
 from .activity_types import ActivityTypes
 from .activity_event_names import ActivityEventNames
 
+if TYPE_CHECKING:
+    from .activity import Activity
 
-class ConversationReference(AgentsModel, _ChannelIdFieldMixin):
-    """An object relating to a particular point in a conversation.
 
-    :param activity_id: (Optional) ID of the activity to refer to
-    :type activity_id: str
-    :param user: (Optional) User participating in this conversation
-    :type user: ~microsoft_agents.activity.ChannelAccount
-    :param agent: Agent participating in this conversation
-    :type agent: ~microsoft_agents.activity.ChannelAccount
-    :param conversation: Conversation reference
-    :type conversation: ~microsoft_agents.activity.ConversationAccount
-    :param channel_id: Channel ID
-    :type channel_id: ~microsoft_agents.activity.ChannelId
-    :param locale: A locale name for the contents of the text field.
-        The locale name is a combination of an ISO 639 two- or three-letter
-        culture code associated with a language and an ISO 3166 two-letter
-        subculture code associated with a country or region.
-        The locale name can also correspond to a valid BCP-47 language tag.
-    :type locale: str
-    :param service_url: Service endpoint where operations concerning the
-     referenced conversation may be performed
-    :type service_url: str
-    """
+class ConversationReference(AgentsModel, _ChannelIdFieldMixin):
+    """An object relating to a particular point in a conversation."""
 
     # optionals here are due to webchat
     activity_id: Optional[NonEmptyString] = None
@@ -49,8 +32,36 @@ class ConversationReference(AgentsModel, _ChannelIdFieldMixin):
     locale: Optional[NonEmptyString] = None
     service_url: NonEmptyString = None
 
-    def get_continuation_activity(self) -> "Activity":  # type: ignore
-        from .activity import Activity
+    if TYPE_CHECKING:
+        def __init__(self,
+            *,
+            channel_id: ChannelId | str | None = None,
+            **kwargs
+        ) -> None:
+            """ 
+            :param activity_id: (Optional) ID of the activity to refer to
+            :type activity_id: str
+            :param user: (Optional) User participating in this conversation
+            :type user: ~microsoft_agents.activity.ChannelAccount
+            :param agent: Agent participating in this conversation
+            :type agent: ~microsoft_agents.activity.ChannelAccount
+            :param conversation: Conversation reference
+            :type conversation: ~microsoft_agents.activity.ConversationAccount
+            :param channel_id: Channel ID
+            :type channel_id: ~microsoft_agents.activity.ChannelId
+            :param locale: A locale name for the contents of the text field.
+                The locale name is a combination of an ISO 639 two- or three-letter
+                culture code associated with a language and an ISO 3166 two-letter
+                subculture code associated with a country or region.
+                The locale name can also correspond to a valid BCP-47 language tag.
+            :type locale: str
+            :param service_url: Service endpoint where operations concerning the
+            referenced conversation may be performed
+            :type service_url: str
+            """
+            ...
+
+    def get_continuation_activity(self) -> Activity:
 
         return Activity(
             type=ActivityTypes.event,
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/token_response.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/token_response.py
index fc4f49f9..5da5701a 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/token_response.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/token_response.py
@@ -41,16 +41,18 @@ def is_exchangeable(self) -> bool:
         try:
             # Decode without verification to check the audience
             payload = jwt.decode(self.token, options={"verify_signature": False})
+        except Exception:
+            return False
 
-            idtyp = payload.get("idtyp")
-            if idtyp == "user":
-                return False
+        idtyp = payload.get("idtyp")
+        if idtyp == "user":
+            return False
 
-            aud = payload.get("aud")
-            app_id = self._get_app_id_from_token_payload(payload)
+        aud = payload.get("aud")
+        app_id = self._get_app_id_from_token_payload(payload)
+        if app_id is not None:
             return isinstance(aud, str) and app_id in aud
-        except Exception:
-            return False
+        return False
 
     @staticmethod
     def _get_app_id_from_token_payload(token_payload: dict) -> Optional[str]:
diff --git a/libraries/microsoft-agents-activity/microsoft_agents/activity/turn_context_protocol.py b/libraries/microsoft-agents-activity/microsoft_agents/activity/turn_context_protocol.py
index e9e613f0..9e6b5fcb 100644
--- a/libraries/microsoft-agents-activity/microsoft_agents/activity/turn_context_protocol.py
+++ b/libraries/microsoft-agents-activity/microsoft_agents/activity/turn_context_protocol.py
@@ -3,7 +3,7 @@
 
 from __future__ import annotations
 
-from typing import Protocol, Callable, Optional, Generic, TypeVar
+from typing import Protocol, Callable, Optional, TypeVar
 from abc import abstractmethod
 
 from microsoft_agents.activity import (
@@ -18,9 +18,9 @@
 T = TypeVar("T", bound=Activity)
 
 
-class TurnContextProtocol(Protocol, Generic[T]):
+class TurnContextProtocol(Protocol):
     adapter: "ChannelAdapterProtocol"
-    activity: Activity | T
+    activity: Activity
     responded: bool
     turn_state: dict
 
diff --git a/libraries/microsoft-agents-copilotstudio-client/microsoft_agents/copilotstudio/client/power_platform_environment.py b/libraries/microsoft-agents-copilotstudio-client/microsoft_agents/copilotstudio/client/power_platform_environment.py
index a25321b1..bf7a80c9 100644
--- a/libraries/microsoft-agents-copilotstudio-client/microsoft_agents/copilotstudio/client/power_platform_environment.py
+++ b/libraries/microsoft-agents-copilotstudio-client/microsoft_agents/copilotstudio/client/power_platform_environment.py
@@ -330,7 +330,7 @@ def get_environment_endpoint(
 
     @staticmethod
     def get_endpoint_suffix(cloud: PowerPlatformCloud, cloud_base_address: str) -> str:
-        return {
+        val = {
             PowerPlatformCloud.LOCAL: "api.powerplatform.localhost",
             PowerPlatformCloud.EXP: "api.exp.powerplatform.com",
             PowerPlatformCloud.DEV: "api.dev.powerplatform.com",
@@ -347,7 +347,10 @@ def get_endpoint_suffix(cloud: PowerPlatformCloud, cloud_base_address: str) -> s
             PowerPlatformCloud.EX: "api.powerplatform.eaglex.ic.gov",
             PowerPlatformCloud.RX: "api.powerplatform.microsoft.scloud",
             PowerPlatformCloud.OTHER: cloud_base_address,
-        }.get(cloud, ValueError(f"Invalid cloud category value: {cloud}"))
+        }.get(cloud)
+        if not val:
+            raise ValueError(f"Invalid cloud category value: {cloud}")
+        return val
 
     @staticmethod
     def get_id_suffix_length(cloud: PowerPlatformCloud) -> int:
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/_oauth/_oauth_flow.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/_oauth/_oauth_flow.py
index 6100c4c1..7f1f0ea3 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/_oauth/_oauth_flow.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/_oauth/_oauth_flow.py
@@ -192,6 +192,11 @@ async def begin_flow(self, activity: Activity) -> _FlowResponse:
             ms_app_id=self._ms_app_id,
         )
 
+        if not token_exchange_state.conversation.channel_id:
+            raise ValueError(
+                "OAuthFlow.begin_flow(): activity must have a channel_id in the conversation reference"
+            )
+
         res = await self._user_token_client.user_token._get_token_or_sign_in_resource(
             activity.from_property.id,
             self._abs_oauth_connection_name,
@@ -271,7 +276,7 @@ async def _continue_from_invoke_token_exchange(
                     self._user_id,
                 )
 
-                return None, _FlowErrorTag.PRECONDITION_FAILED
+                return TokenResponse(), _FlowErrorTag.PRECONDITION_FAILED
             raise
 
     async def continue_flow(self, activity: Activity) -> _FlowResponse:
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/agent_application.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/agent_application.py
index d4d6ee6e..33160264 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/agent_application.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/agent_application.py
@@ -10,6 +10,7 @@
 from contextlib import nullcontext
 from copy import copy
 from functools import partial
+from warnings import deprecated
 
 import re
 from typing import (
@@ -74,22 +75,22 @@ class AgentApplication(Agent, Generic[StateT]):
     typing: TypingIndicator
 
     _options: ApplicationOptions
-    _adapter: Optional[ChannelServiceAdapter] = None
+    _adapter: ChannelServiceAdapter | None = None
     _auth: Authorization
-    _proactive: Optional[Proactive] = None
+    _proactive: Proactive | None = None
     _internal_before_turn: list[Callable[[TurnContext, StateT], Awaitable[bool]]]
     _internal_after_turn: list[Callable[[TurnContext, StateT], Awaitable[bool]]]
     _route_list: _RouteList[StateT]
-    _error: Optional[Callable[[TurnContext, Exception], Awaitable[None]]] = None
-    _turn_state_factory: Optional[Callable[[TurnContext], StateT]] = None
+    _error: Callable[[TurnContext, Exception], Awaitable[None]] | None = None
+    _turn_state_factory: Callable[[], StateT] | None = None
     _connection_manager: Connections
 
     def __init__(
         self,
-        options: Optional[ApplicationOptions] = None,
+        options: ApplicationOptions | None = None,
         *,
-        connection_manager: Optional[Connections] = None,
-        authorization: Optional[Authorization] = None,
+        connection_manager: Connections | None = None,
+        authorization: Authorization | None = None,
         **kwargs,
     ) -> None:
         """
@@ -131,6 +132,8 @@ def __init__(
             raise ApplicationError("""
                 The `ApplicationOptions.storage` property is required and was not configured.
                 """)
+        
+        self._storage = self._options.storage
 
         if options.long_running_messages and (
             not options.adapter or not options.bot_app_id
@@ -150,13 +153,13 @@ def __init__(
         self._turn_state_factory = (
             options.turn_state_factory
             or kwargs.get("turn_state_factory", None)
-            or partial(TurnState.with_storage, self._options.storage)
+            or partial(StateT.with_storage, self._storage)
         )
 
         if options.proactive:
             proactive_opts = copy(options.proactive)
             if not proactive_opts.storage:
-                proactive_opts.storage = self._options.storage
+                proactive_opts.storage = self._storage
             self._proactive = Proactive(self, proactive_opts)
 
         # TODO: decide how to initialize the Authorization (params vs options vs kwargs)
@@ -186,7 +189,7 @@ def __init__(
                 if key not in ["storage", "connection_manager", "handlers"]
             }
             self._auth = Authorization(
-                storage=self._options.storage,
+                storage=self._storage,
                 connection_manager=connection_manager,
                 auth_handlers=options.authorization_handlers,
                 **auth_options,
@@ -378,7 +381,7 @@ def __selector(context: TurnContext):
 
         def __call(func: RouteHandler[StateT]) -> RouteHandler[StateT]:
             logger.debug(
-                f"Registering activity handler for route handler {func.__name__} with type: {activity_type} with auth handlers: {auth_handlers}"
+                f"Registering activity handler for route handler {func.__qualname__} with type: {activity_type} with auth handlers: {auth_handlers}"
             )
             self.add_route(__selector, func, auth_handlers=auth_handlers, **kwargs)
             return func
@@ -432,7 +435,7 @@ def __selector(context: TurnContext):
 
         def __call(func: RouteHandler[StateT]) -> RouteHandler[StateT]:
             logger.debug(
-                f"Registering message handler for route handler {func.__name__} with select: {select} with auth handlers: {auth_handlers}"
+                f"Registering message handler for route handler {func.__qualname__} with select: {select} with auth handlers: {auth_handlers}"
             )
             self.add_route(__selector, func, auth_handlers=auth_handlers, **kwargs)
             return func
@@ -488,7 +491,7 @@ def __selector(context: TurnContext):
 
         def __call(func: RouteHandler[StateT]) -> RouteHandler[StateT]:
             logger.debug(
-                f"Registering conversation update handler for route handler {func.__name__} with type: {update_type} with auth handlers: {auth_handlers}"
+                f"Registering conversation update handler for route handler {func.__qualname__} with type: {update_type} with auth handlers: {auth_handlers}"
             )
             self.add_route(__selector, func, auth_handlers=auth_handlers, **kwargs)
             return func
@@ -540,7 +543,7 @@ def __selector(context: TurnContext):
 
         def __call(func: RouteHandler[StateT]) -> RouteHandler[StateT]:
             logger.debug(
-                f"Registering message reaction handler for route handler {func.__name__} with type: {reaction_type} with auth handlers: {auth_handlers}"
+                f"Registering message reaction handler for route handler {func.__qualname__} with type: {reaction_type} with auth handlers: {auth_handlers}"
             )
             self.add_route(__selector, func, auth_handlers=auth_handlers, **kwargs)
             return func
@@ -605,7 +608,7 @@ def __selector(context: TurnContext):
 
         def __call(func: RouteHandler[StateT]) -> RouteHandler[StateT]:
             logger.debug(
-                f"Registering message update handler for route handler {func.__name__} with type: {update_type} with auth handlers: {auth_handlers}"
+                f"Registering message update handler for route handler {func.__qualname__} with type: {update_type} with auth handlers: {auth_handlers}"
             )
             self.add_route(__selector, func, auth_handlers=auth_handlers, **kwargs)
             return func
@@ -687,7 +690,7 @@ async def __handler(context: TurnContext, state: StateT):
                 )
 
             logger.debug(
-                f"Registering handoff handler for route handler {func.__name__} with auth handlers: {auth_handlers}"
+                f"Registering handoff handler for route handler {func.__qualname__} with auth handlers: {auth_handlers}"
             )
 
             self.add_route(__selector, __handler, auth_handlers=auth_handlers, **kwargs)
@@ -793,7 +796,7 @@ async def on_error(context: TurnContext, err: Exception):
 
         return func
 
-    def turn_state_factory(self, func: Callable[[TurnContext], Awaitable[StateT]]):
+    def turn_state_factory(self, func: Callable[[], StateT]):
         """
         Custom Turn State Factory
         """
@@ -872,6 +875,7 @@ def _remove_mentions(self, context: TurnContext):
         ):
             context.activity.text = context.remove_recipient_mention(context.activity)
 
+    @deprecated("Use `load_configuration_from_env` instead.")
     @staticmethod
     def parse_env_vars_configuration(vars: dict[str, Any]) -> dict:
         """
@@ -908,12 +912,12 @@ async def _initialize_state(self, context: TurnContext) -> StateT:
             turn_state = self._turn_state_factory()
         else:
             logger.debug("Using default turn state factory")
-            turn_state = TurnState.with_storage(self._options.storage)
+            turn_state = TurnState.with_storage(self._storage)
 
         turn_state = cast(StateT, turn_state)
 
         logger.debug("Loading turn state from storage")
-        await turn_state.load(context, self._options.storage)
+        await turn_state.load(context, self._storage)
         turn_state.temp.input = context.activity.text
         return turn_state
 
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/app_options.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/app_options.py
index 283168f2..02e17749 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/app_options.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/app_options.py
@@ -20,7 +20,6 @@
 from .state.turn_state import TurnState
 from .proactive.proactive_options import ProactiveOptions
 
-
 @dataclass
 class ApplicationOptions:
     adapter: Optional[ChannelServiceAdapter] = None
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_authorization_handler.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_authorization_handler.py
index 542b74cb..5c9709ee 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_authorization_handler.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_authorization_handler.py
@@ -55,10 +55,14 @@ def __init__(
 
         self._storage = storage
         self._connection_manager = connection_manager
-
+        
         if auth_handler:
             self._handler = auth_handler
         else:
+            if not auth_handler_settings:
+                raise ValueError(
+                    "auth_handler_settings must be provided if auth_handler is not."
+                )
             self._handler = AuthHandler._from_settings(auth_handler_settings)
 
         self._id = auth_handler_id or self._handler.name
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_user_authorization.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_user_authorization.py
index 3dd21bf1..166af8d3 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_user_authorization.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/_user_authorization.py
@@ -5,7 +5,7 @@
 
 from __future__ import annotations
 import logging
-from typing import Optional
+from typing import Optional, cast
 
 from microsoft_agents.activity import (
     Activity,
@@ -36,6 +36,7 @@
     _FlowStorageClient,
     _FlowStateTag,
 )
+from microsoft_agents.hosting.core.authorization import ClaimsIdentity
 from .._sign_in_response import _SignInResponse
 from ._authorization_handler import _AuthorizationHandler
 from ..telemetry import spans
@@ -65,9 +66,13 @@ async def _load_flow(
             context and the specified auth handler.
         :rtype: tuple[OAuthFlow, FlowStorageClient]
         """
-        user_token_client: UserTokenClient = context.turn_state.get(
-            context.adapter.USER_TOKEN_CLIENT_KEY
-        )
+        user_token_client: UserTokenClient | None = cast(UserTokenClient | None,
+            context.turn_state.get(
+                context.adapter.USER_TOKEN_CLIENT_KEY
+            ))
+
+        if not user_token_client:
+            raise ValueError("UserTokenClient is required in turn state")
 
         if (
             not context.activity.channel_id
@@ -79,14 +84,17 @@ async def _load_flow(
         channel_id = context.activity.channel_id
         user_id = context.activity.from_property.id
 
-        ms_app_id = context.turn_state.get(context.adapter.AGENT_IDENTITY_KEY).claims[
-            "aud"
-        ]
+        identity = cast(ClaimsIdentity | None, context.turn_state.get(context.adapter.AGENT_IDENTITY_KEY))
+
+        if not identity:
+            raise ValueError("ClaimsIdentity is required in turn state")
+        
+        ms_app_id = identity.claims["aud"]
 
         # try to load existing state
         flow_storage_client = _FlowStorageClient(channel_id, user_id, self._storage)
         logger.info("Loading OAuth flow state from storage")
-        flow_state: _FlowState = await flow_storage_client.read(self._id)
+        flow_state: _FlowState | None = await flow_storage_client.read(self._id)
         if not flow_state:
             logger.info("No existing flow state found, creating new flow state")
             flow_state = _FlowState(
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/agentic_user_authorization.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/agentic_user_authorization.py
index 548edaab..27d77485 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/agentic_user_authorization.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/agentic_user_authorization.py
@@ -75,8 +75,19 @@ async def get_agentic_instance_token(self, context: TurnContext) -> TokenRespons
         )
         agentic_instance_id = context.activity.get_agentic_instance_id()
         assert agentic_instance_id
+
+        tenant_id = context.activity.get_agentic_tenant_id()
+        if not tenant_id:
+            logger.error(
+                "Unable to retrieve agentic instance token: missing agentic tenant Id. Agentic Tenant ID: %s",
+                tenant_id,
+            )
+            raise ValueError(
+                f"Unable to retrieve agentic instance token: missing agentic tenant Id. Agentic Tenant ID: {tenant_id}"
+            )
+
         instance_token, _ = await connection.get_agentic_instance_token(
-            context.activity.get_agentic_tenant_id(), agentic_instance_id
+            tenant_id, agentic_instance_id
         )
         return (
             TokenResponse(token=instance_token) if instance_token else TokenResponse()
@@ -130,9 +141,19 @@ async def get_agentic_user_token(
             raise ValueError(
                 f"Unable to retrieve agentic user token: missing agentic User Id or agentic instance Id. agentic_user_id: {agentic_user_id}, Agentic Instance ID: {agentic_instance_id}"
             )
+        
+        tenant_id = context.activity.get_agentic_tenant_id()
+        if not tenant_id:
+            logger.error(
+                "Unable to retrieve agentic user token: missing agentic tenant Id. Agentic Tenant ID: %s",
+                tenant_id,
+            )
+            raise ValueError(
+                f"Unable to retrieve agentic user token: missing agentic tenant Id. Agentic Tenant ID: {tenant_id}"
+            )
 
         token = await connection.get_agentic_user_token(
-            context.activity.get_agentic_tenant_id(),
+            tenant_id,
             agentic_instance_id,
             agentic_user_id,
             scopes,
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/connector_user_authorization.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/connector_user_authorization.py
index 61f838f7..93606924 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/connector_user_authorization.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/_handlers/connector_user_authorization.py
@@ -196,7 +196,7 @@ async def _handle_obo(
             scopes=scopes,
             user_assertion=input_token_response.token,
         )
-        return TokenResponse(token=token) if token else None
+        return TokenResponse(token=token)
 
     def _create_token_response(self, context: TurnContext) -> TokenResponse:
         """
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/authorization.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/authorization.py
index 51cc75bc..132253a8 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/authorization.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/oauth/authorization.py
@@ -282,8 +282,9 @@ async def _start_or_continue_sign_in(
 
         elif sign_in_response.tag in [_FlowStateTag.BEGIN, _FlowStateTag.CONTINUE]:
             # Handling special case for Teams SSO, ConsentRequired
+            channel = context.activity.channel_id.channel if context.activity.channel_id else None
             if not (
-                context.activity.channel_id.channel == Channels.ms_teams
+                channel == Channels.ms_teams
                 and sign_in_state.continuation_activity
                 and context.activity.type == ActivityTypes.invoke
                 and context.activity.name
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/proactive/conversation.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/proactive/conversation.py
index aadc876a..3c205401 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/proactive/conversation.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/proactive/conversation.py
@@ -5,7 +5,7 @@
 
 from __future__ import annotations
 
-from typing import Optional, TYPE_CHECKING
+from typing import Optional, TYPE_CHECKING, cast
 
 from microsoft_agents.activity import ConversationReference
 from microsoft_agents.hosting.core.authorization import ClaimsIdentity
@@ -67,9 +67,12 @@ def from_turn_context(cls, context: "TurnContext") -> "Conversation":
         """
         from microsoft_agents.hosting.core.channel_adapter import ChannelAdapter
 
-        identity: Optional[ClaimsIdentity] = context.turn_state.get(
-            ChannelAdapter.AGENT_IDENTITY_KEY
-        )
+        identity: Optional[ClaimsIdentity] = cast(
+            ClaimsIdentity | None,
+            context.turn_state.get(
+                ChannelAdapter.AGENT_IDENTITY_KEY
+            ))
+        
         reference = context.activity.get_conversation_reference()
         return cls(identity or {}, reference)
 
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py
index 4466b98b..b23bc54d 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py
@@ -4,7 +4,9 @@
 import uuid
 import asyncio
 import logging
-from typing import Optional, Callable, Literal, cast
+from typing import Optional, Callable, Literal, cast, TYPE_CHECKING
+if TYPE_CHECKING:
+    from microsoft_agents.hosting.core.turn_context import TurnContext
 
 from microsoft_agents.activity import (
     Activity,
@@ -39,7 +41,7 @@ class StreamingResponse:
     Once `end_stream()` is called, the stream is considered ended and no further updates can be sent.
     """
 
-    def __init__(self, context: "TurnContext"):
+    def __init__(self, context: TurnContext):
         """
         Creates a new StreamingResponse instance.
 
@@ -267,7 +269,7 @@ async def wait_for_queue(self) -> None:
         if self._queue_sync:
             await self._queue_sync
 
-    def _set_defaults(self, context: "TurnContext"):
+    def _set_defaults(self, context: TurnContext):
 
         channel = (
             context.activity.channel_id.channel if context.activity.channel_id else None
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_adapter.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_adapter.py
index 7d00fc3a..1be540ad 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_adapter.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_adapter.py
@@ -1,6 +1,8 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
+from __future__ import annotations
+
 from abc import ABC, abstractmethod
 from collections.abc import Callable
 from typing import Awaitable
@@ -8,6 +10,7 @@
 from microsoft_agents.activity import ChannelAdapterProtocol
 from microsoft_agents.activity import (
     Activity,
+    ActivityTypes,
     ConversationAccount,
     ConversationReference,
     ConversationParameters,
@@ -15,7 +18,7 @@
 )
 
 from .turn_context import TurnContext
-from .middleware_set import MiddlewareSet
+from .middleware_set import MiddlewareSet, Middleware
 
 
 class ChannelAdapter(ABC, ChannelAdapterProtocol):
@@ -78,7 +81,7 @@ async def delete_activity(
         """
         raise NotImplementedError()
 
-    def use(self, middleware):
+    def use(self, middleware: Middleware) -> ChannelAdapter:
         """
         Registers a middleware handler with the adapter.
 
@@ -179,7 +182,6 @@ async def create_conversation(
             If the conversation is established with the specified users, the ID of the activity
             will contain the ID of the new conversation.
         """
-        from microsoft_agents.activity import ActivityTypes
 
         # If credentials are not provided, we can't create a conversation
         if not conversation_parameters:
@@ -202,11 +204,11 @@ async def create_conversation(
 
         # Create a conversation update activity
         conversation_update = Activity(
-            type=ActivityTypes.CONVERSATION_UPDATE,
+            type=ActivityTypes.conversation_update,
             channel_id=channel_id,
             service_url=service_url,
             conversation=conversation_parameters.conversation,
-            recipient=conversation_parameters.bot,
+            recipient=conversation_parameters.agent,
             from_property=conversation_parameters.members[0],
             members_added=conversation_parameters.members,
         )
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_service_adapter.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_service_adapter.py
index 752ae078..0365c882 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_service_adapter.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/channel_service_adapter.py
@@ -130,13 +130,12 @@ async def update_activity(self, context: TurnContext, activity: Activity):
         :type activity: :class:`microsoft_agents.activity.Activity`
         :return: Resource response for the updated activity.
         :rtype: :class:`microsoft_agents.activity.ResourceResponse`
-        :raises TypeError: If context or activity are None/invalid.
+        :raises TypeError: If activity ID is None.
+        :raises RuntimeError: If unable to extract ConnectorClient from turn context.
         """
-        if not context:
-            raise TypeError("Expected TurnContext but got None instead")
 
-        if activity is None:
-            raise TypeError("Expected Activity but got None instead")
+        if activity.id is None:
+            raise TypeError("Activity ID is required to update an activity.")
 
         with spans.AdapterUpdateActivity(activity):
 
@@ -145,7 +144,7 @@ async def update_activity(self, context: TurnContext, activity: Activity):
                 context.turn_state.get(self._AGENT_CONNECTOR_CLIENT_KEY),
             )
             if not connector_client:
-                raise Error("Unable to extract ConnectorClient from turn context.")
+                raise RuntimeError("Unable to extract ConnectorClient from turn context.")
 
             return await connector_client.conversations.update_activity(
                 activity.conversation.id, activity.id, activity
@@ -161,13 +160,12 @@ async def delete_activity(
         :type context: :class:`microsoft_agents.hosting.core.turn_context.TurnContext`
         :param reference: Reference to the conversation and activity to delete.
         :type reference: :class:`microsoft_agents.activity.ConversationReference`
-        :raises TypeError: If context or reference are None/invalid.
+        :raises TypeError: If reference.activity_id is None.
+        :raises RuntimeError: If unable to extract ConnectorClient from turn context.
         """
-        if not context:
-            raise TypeError("Expected TurnContext but got None instead")
 
-        if not reference:
-            raise TypeError("Expected ConversationReference but got None instead")
+        if not reference.activity_id:
+            raise TypeError("Activity ID is required to delete an activity.")
 
         with spans.AdapterDeleteActivity(context.activity):
 
@@ -176,7 +174,7 @@ async def delete_activity(
                 context.turn_state.get(self._AGENT_CONNECTOR_CLIENT_KEY),
             )
             if not connector_client:
-                raise Error("Unable to extract ConnectorClient from turn context.")
+                raise RuntimeError("Unable to extract ConnectorClient from turn context.")
 
             await connector_client.conversations.delete_activity(
                 reference.conversation.id, reference.activity_id
@@ -272,7 +270,7 @@ async def create_conversation(  # pylint: disable=arguments-differ
         claims_identity.claims[AuthenticationConstants.SERVICE_URL_CLAIM] = service_url
 
         # Create the connector client to use for outbound requests.
-        connector_client: ConnectorClient = (
+        connector_client: ConnectorClientBase = (
             await self._channel_service_client_factory.create_connector_client(
                 None, claims_identity, service_url, audience
             )
@@ -300,7 +298,7 @@ async def create_conversation(  # pylint: disable=arguments-differ
         context.turn_state[self._AGENT_CONNECTOR_CLIENT_KEY] = connector_client
 
         # Create a UserTokenClient instance for the application to use. (For example, in the OAuthPrompt.)
-        user_token_client: UserTokenClient = (
+        user_token_client = (
             await self._channel_service_client_factory.create_user_token_client(
                 context, claims_identity
             )
@@ -329,7 +327,7 @@ async def process_proactive(
             activity=continuation_activity,
         )
 
-        user_token_client: UserTokenClient = (
+        user_token_client = (
             await self._channel_service_client_factory.create_user_token_client(
                 context, claims_identity
             )
@@ -337,7 +335,7 @@ async def process_proactive(
         context.turn_state[self.USER_TOKEN_CLIENT_KEY] = user_token_client
 
         # Create the connector client to use for outbound requests.
-        connector_client: ConnectorClient = (
+        connector_client = (
             await self._channel_service_client_factory.create_connector_client(
                 context, claims_identity, continuation_activity.service_url, audience
             )
@@ -368,7 +366,7 @@ async def process_activity(
         claims_identity: ClaimsIdentity,
         activity: Activity,
         callback: Callable[[TurnContext], Awaitable],
-    ):
+    ) -> InvokeResponse | None:
         """
         Creates a turn context and runs the middleware pipeline for an incoming activity.
 
@@ -415,7 +413,7 @@ async def process_activity(
         )
 
         # Create a UserTokenClient instance for the OAuth flow.
-        user_token_client: UserTokenClient = (
+        user_token_client = (
             await self._channel_service_client_factory.create_user_token_client(
                 context, claims_identity, use_anonymous_auth_callback
             )
@@ -423,7 +421,7 @@ async def process_activity(
         context.turn_state[self.USER_TOKEN_CLIENT_KEY] = user_token_client
 
         # Create the connector client to use for outbound requests.
-        connector_client: Optional[ConnectorClient] = None
+        connector_client: ConnectorClientBase | None = None
         if self._resolve_if_connector_client_is_needed(activity):
             connector_client = (
                 await self._channel_service_client_factory.create_connector_client(
@@ -503,7 +501,7 @@ def _create_create_activity(
     def _create_turn_context(
         self,
         claims_identity: ClaimsIdentity,
-        oauth_scope: str,
+        oauth_scope: str | None,
         callback: Callable[[TurnContext], Awaitable],
         activity: Optional[Activity] = None,
     ) -> TurnContext:
@@ -518,7 +516,7 @@ def _create_turn_context(
 
         return context
 
-    def _process_turn_results(self, context: TurnContext) -> Optional[InvokeResponse]:
+    def _process_turn_results(self, context: TurnContext) -> InvokeResponse | None:
         """Process the results of a turn and return the appropriate response.
 
         :param context: The turn context
@@ -541,11 +539,11 @@ def _process_turn_results(self, context: TurnContext) -> Optional[InvokeResponse
         if context.activity.type == ActivityTypes.invoke:
 
             with spans.AdapterSendActivities([context.activity]):
-                activity_invoke_response: Activity = context.turn_state.get(
+                activity_invoke_response: Activity | None = cast(Activity | None, context.turn_state.get(
                     self.INVOKE_RESPONSE_KEY
-                )
+                ))
                 if not activity_invoke_response:
-                    return InvokeResponse(status=HTTPStatus.OK)
+                    return InvokeResponse(status=HTTPStatus.NOT_IMPLEMENTED)
 
                 return InvokeResponse.model_validate(activity_invoke_response.value)
 
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_factory_protocol.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_factory_protocol.py
index a55001cc..fc1e1775 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_factory_protocol.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_factory_protocol.py
@@ -10,4 +10,4 @@
 
 class ChannelFactoryProtocol(Protocol):
     def create_channel(self, token_access: AccessTokenProviderBase) -> ChannelProtocol:
-        pass
+        raise NotImplementedError("create_channel must be implemented by subclasses")
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_host_protocol.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_host_protocol.py
index a2990357..9227a117 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_host_protocol.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_host_protocol.py
@@ -8,6 +8,11 @@
 
 
 class ChannelHostProtocol(Protocol):
+
+    host_endpoint: str
+    host_app_id: str
+    channels: dict[str, ChannelInfoProtocol]
+
     def __init__(
         self,
         host_endpoint: str,
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_protocol.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_protocol.py
index a5855af0..c045b3d0 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_protocol.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channel_protocol.py
@@ -16,7 +16,7 @@ async def post_activity(
         conversation_id: str,
         activity: Activity,
         *,
-        response_body_type: type[AgentsModel] = None,
+        response_body_type: type[AgentsModel] | None = None,
         **kwargs,
     ) -> InvokeResponse:
         raise NotImplementedError()
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channels_configuration.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channels_configuration.py
index 03547f23..8d6b32b9 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channels_configuration.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/client/channels_configuration.py
@@ -39,4 +39,6 @@ class ChannelsConfiguration(Protocol):
 
     @staticmethod
     def CHANNEL_HOST_CONFIGURATION() -> ChannelHostConfiguration:
-        pass
+        raise NotImplementedError(
+            "ChannelsConfiguration.CHANNEL_HOST_CONFIGURATION() must be implemented"
+        )
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/connector_client_base.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/connector_client_base.py
index 545c5177..18bbde3b 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/connector_client_base.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/connector_client_base.py
@@ -23,3 +23,8 @@ def attachments(self) -> AttachmentsBase:
     @abstractmethod
     def conversations(self) -> ConversationsBase:
         pass
+
+    @abstractmethod
+    async def close(self) -> None:
+        """Close the client and release any resources."""
+        raise NotImplementedError("Subclasses must implement the close method.")
\ No newline at end of file
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/user_token_client_base.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/user_token_client_base.py
index 7c398a58..7de00219 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/user_token_client_base.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/connector/user_token_client_base.py
@@ -9,6 +9,7 @@
 
 
 class UserTokenClientBase(Protocol):
+
     @property
     @abstractmethod
     def agent_sign_in(self) -> AgentSignInBase:
@@ -18,3 +19,9 @@ def agent_sign_in(self) -> AgentSignInBase:
     @abstractmethod
     def user_token(self) -> UserTokenBase:
         pass
+
+
+    @abstractmethod
+    async def close(self) -> None:
+        """Close the client and release any resources."""
+        raise NotImplementedError("Subclasses must implement the close method.")
\ No newline at end of file
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/http/_http_adapter_base.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/http/_http_adapter_base.py
index 4ea5438b..0ddfec57 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/http/_http_adapter_base.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/http/_http_adapter_base.py
@@ -5,6 +5,7 @@
 
 from abc import ABC
 from traceback import format_exc
+from http import HTTPStatus
 
 from microsoft_agents.activity import Activity, DeliveryModes
 from microsoft_agents.hosting.core.authorization import ClaimsIdentity, Connections
@@ -58,6 +59,9 @@ async def on_turn_error(context: TurnContext, error: Exception):
 
         self.on_turn_error = on_turn_error
 
+        if not connection_manager:
+            raise ValueError("HttpAdapterBase.__init__: connection_manager can't be None")
+
         channel_service_client_factory = (
             channel_service_client_factory
             or RestChannelServiceClientFactory(connection_manager)
@@ -128,8 +132,10 @@ async def process_request(
                 ):
                     with spans.AdapterWriteResponse(activity):
                         # Invoke and ExpectReplies cannot be performed async
+                        invoke_response_status = invoke_response.status if invoke_response else None
                         return HttpResponseFactory.json(
-                            invoke_response.body, invoke_response.status
+                            invoke_response.body if invoke_response else None,
+                            invoke_response_status or HTTPStatus.NOT_IMPLEMENTED,
                         )
 
                 return HttpResponseFactory.accepted()
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/message_factory.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/message_factory.py
index 91a55730..77a1f8b3 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/message_factory.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/message_factory.py
@@ -88,9 +88,9 @@ def suggested_actions(
         :param input_hint:
         :return:
         """
-        actions = SuggestedActions(actions=actions)
+        suggested_actions = SuggestedActions(actions=actions)
         message = Activity(
-            type=ActivityTypes.message, input_hint=input_hint, suggested_actions=actions
+            type=ActivityTypes.message, input_hint=input_hint, suggested_actions=suggested_actions
         )
         if text:
             message.text = text
@@ -122,16 +122,14 @@ def attachment(
         :param input_hint:
         :return:
         """
-        return attachment_activity(
-            AttachmentLayoutTypes.list, [attachment], text, speak, input_hint
-        )
+        return MessageFactory.list([attachment], text, speak, input_hint)
 
     @staticmethod
     def list(
         attachments: list[Attachment],
         text: str | None = None,
         speak: str | None = None,
-        input_hint: InputHints | str = None,
+        input_hint: InputHints | str | None = None,
     ) -> Activity:
         """
         Returns a message that will display a set of attachments in list form.
@@ -154,6 +152,10 @@ def list(
         :param input_hint:
         :return:
         """
+        if not input_hint:
+            return attachment_activity(
+                AttachmentLayoutTypes.list, attachments, text, speak
+            )
         return attachment_activity(
             AttachmentLayoutTypes.list, attachments, text, speak, input_hint
         )
@@ -163,7 +165,7 @@ def carousel(
         attachments: list[Attachment],
         text: str | None = None,
         speak: str | None = None,
-        input_hint: InputHints | str = None,
+        input_hint: InputHints | str | None = None,
     ) -> Activity:
         """
         Returns a message that will display a set of attachments using a carousel layout.
@@ -186,6 +188,10 @@ def carousel(
         :param input_hint:
         :return:
         """
+        if not input_hint:
+            return attachment_activity(
+                AttachmentLayoutTypes.carousel, attachments, text, speak
+            )
         return attachment_activity(
             AttachmentLayoutTypes.carousel, attachments, text, speak, input_hint
         )
@@ -218,6 +224,4 @@ def content_url(
         attachment = Attachment(content_type=content_type, content_url=url)
         if name:
             attachment.name = name
-        return attachment_activity(
-            AttachmentLayoutTypes.list, [attachment], text, speak, input_hint
-        )
+        return MessageFactory.attachment(attachment, text, speak, input_hint)
\ No newline at end of file
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/rest_channel_service_client_factory.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/rest_channel_service_client_factory.py
index e1347b78..af25d044 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/rest_channel_service_client_factory.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/rest_channel_service_client_factory.py
@@ -70,17 +70,21 @@ async def _get_agentic_token(self, context: TurnContext, service_url: str) -> st
         agent_instance_id = context.activity.get_agentic_instance_id()
         if not agent_instance_id:
             raise ValueError("Agent instance ID is required for agentic identity role")
+        
+        tenant_id = context.activity.get_agentic_tenant_id()
+        if not tenant_id:
+            raise ValueError("Tenant ID is required for agentic identity role")
 
         if context.activity.recipient.role == RoleTypes.agentic_identity:
             token, _ = await connection.get_agentic_instance_token(
-                context.activity.get_agentic_tenant_id(), agent_instance_id
+                tenant_id, agent_instance_id
             )
         else:
             agentic_user = context.activity.get_agentic_user()
             if not agentic_user:
                 raise ValueError("Agentic user is required for agentic user role")
             token = await connection.get_agentic_user_token(
-                context.activity.get_agentic_tenant_id(),
+                tenant_id,
                 agent_instance_id,
                 agentic_user,
                 [AuthenticationConstants.APX_PRODUCTION_SCOPE],
@@ -163,7 +167,7 @@ async def create_user_token_client(
         if not context or not claims_identity:
             raise ValueError("context and claims_identity are required")
 
-        scopes = claims_identity.get_token_scope() if claims_identity else None
+        scopes = claims_identity.get_token_scope() if claims_identity else []
 
         with spans.AdapterCreateUserTokenClient(
             token_service_endpoint=self._token_service_endpoint,
diff --git a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/turn_context.py b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/turn_context.py
index 3bd9a7cd..24b087b7 100644
--- a/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/turn_context.py
+++ b/libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/turn_context.py
@@ -3,21 +3,23 @@
 from __future__ import annotations
 
 import re
-from typing import Optional
+from typing import Optional, Awaitable, Any
 
-from copy import copy, deepcopy
+from copy import deepcopy
 from collections.abc import Callable
 from datetime import datetime, timezone
-from microsoft_agents.activity import TurnContextProtocol
+
 from microsoft_agents.activity import (
     Activity,
     ActivityTypes,
     ConversationReference,
+    DeliveryModes,
     InputHints,
     Mention,
     ResourceResponse,
-    DeliveryModes,
+    TurnContextProtocol,
 )
+from microsoft_agents.activity._model_utils import pick_model, SkipNone
 from microsoft_agents.activity.entity.entity_types import EntityTypes
 from microsoft_agents.hosting.core.authorization.claims_identity import ClaimsIdentity
 import microsoft_agents.hosting.core.telemetry.turn_context.spans as spans
@@ -40,32 +42,35 @@ def __init__(
         :param adapter_or_context:
         :param request:
         """
+        _activity: Activity | None = None
         if isinstance(adapter_or_context, TurnContext):
             adapter_or_context.copy_to(self)
             self._identity = adapter_or_context.identity
+            _activity = self._activity
         else:
             self.adapter = adapter_or_context
-            self._activity = request  # exception thrown if None further down
+            _activity = request
             self.responses: list[Activity] = []
             self._services: dict = {}
-            self._on_send_activities: Callable[
-                ["TurnContext", list[Activity], Callable], list[ResourceResponse]
-            ] = []
-            self._on_update_activity: Callable[
-                ["TurnContext", Activity, Callable], ResourceResponse
-            ] = []
-            self._on_delete_activity: Callable[
-                ["TurnContext", ConversationReference, Callable], None
-            ] = []
+            self._on_send_activities: list[Callable[
+                [TurnContext, list[Activity], Callable], list[ResourceResponse]
+            ]] = []
+            self._on_update_activity: list[Callable[
+                [TurnContext, Activity, Callable], ResourceResponse
+            ]] = []
+            self._on_delete_activity: list[Callable[
+                [TurnContext, ConversationReference, Callable], None
+            ]] = []
             self._responded: bool = False
             self._identity = identity
 
         if self.adapter is None:
             raise TypeError("TurnContext must be instantiated with an adapter.")
-        if self._activity is None:
+        if _activity is None:
             raise TypeError(
                 "TurnContext must be instantiated with a request parameter of type Activity."
             )
+        self._activity = _activity
 
         self._turn_state = {}
 
@@ -319,9 +324,14 @@ def on_delete_activity(self, handler) -> "TurnContext":
         self._on_delete_activity.append(handler)
         return self
 
-    async def _emit(self, plugins, arg, logic):
-        handlers = copy(plugins)
-
+    async def _emit(
+        self,
+        plugins: list[Callable],
+        arg: Any,
+        logic: Awaitable[Any],
+    ) -> Any:
+        handlers = list(plugins)
+        
         async def emit_next(i: int):
             context = self
             try:
@@ -346,13 +356,14 @@ async def send_trace_activity(
         value_type: str | None = None,
         label: str | None = None,
     ) -> ResourceResponse:
-        trace_activity = Activity(
+        trace_activity = pick_model(
+            Activity,
             type=ActivityTypes.trace,
             timestamp=datetime.now(timezone.utc),
             name=name,
             value=value,
-            value_type=value_type,
-            label=label,
+            value_type=SkipNone(value_type),
+            label=SkipNone(label),
         )
 
         return await self.send_activity(trace_activity)