diff --git a/MIGRATION_A365.md b/MIGRATION_A365.md
index 4b477f9a..c7d57419 100644
--- a/MIGRATION_A365.md
+++ b/MIGRATION_A365.md
@@ -38,6 +38,20 @@ pip uninstall -y microsoft-agents-a365-observability-extensions-agent-framework
 pip install microsoft-opentelemetry
 ```
 
+> If you use the hosting middleware (`BaggageMiddleware`,
+> `ObservabilityHostingManager`, etc.), install the `hosting` extra,
+> which pulls in `microsoft-agents-activity` and
+> `microsoft-agents-hosting-core`:
+>
+> ```bash
+> pip install "microsoft-opentelemetry[hosting]"
+> ```
+>
+> If those packages are not installed, importing from
+> `microsoft.opentelemetry.a365.hosting` logs an error with the install
+> command but does not crash; the middleware will fail at runtime when
+> invoked.
+
 ## Step 2 — Rewrite Import Paths
 
 The old packages used `microsoft_agents_a365.*` namespace.
diff --git a/dev_requirements.txt b/dev_requirements.txt
index 37e0ebe1..09a15ff8 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -2,3 +2,5 @@ pytest>=8.0
 pytest-asyncio>=0.23.0
 pytest-cov>=5.0
 black>=24.0
+microsoft-agents-activity
+microsoft-agents-hosting-core
diff --git a/pyproject.toml b/pyproject.toml
index f8d7fa49..c95f63cc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,8 +42,6 @@ dependencies = [
     "opentelemetry-resource-detector-azure<1.0.0,>=0.1.5",
     "wrapt>=1.0",
     "opentelemetry-util-genai==0.3b0",
-    "microsoft-agents-activity>=0.9.0",
-    "microsoft-agents-hosting-core>=0.9.0",
     "aiohttp>=3.8.0",
     "PyJWT",
     "requests"
@@ -59,6 +57,10 @@ agent-framework = [
 openai-agents = [
     "openai-agents>=0.0.7",
 ]
+hosting = [
+    "microsoft-agents-activity>=0.9.0",
+    "microsoft-agents-hosting-core>=0.9.0",
+]
 test = [
     "pytest>=8.0",
     "pytest-cov>=5.0",
diff --git a/src/microsoft/opentelemetry/a365/hosting/middleware/baggage_middleware.py b/src/microsoft/opentelemetry/a365/hosting/middleware/baggage_middleware.py
index d2f469e8..c652de0e 100644
--- a/src/microsoft/opentelemetry/a365/hosting/middleware/baggage_middleware.py
+++ b/src/microsoft/opentelemetry/a365/hosting/middleware/baggage_middleware.py
@@ -5,10 +5,18 @@
 
 from __future__ import annotations
 
+import logging
 from collections.abc import Awaitable, Callable
 
-from microsoft_agents.activity import ActivityEventNames, ActivityTypes
-from microsoft_agents.hosting.core.turn_context import TurnContext
+try:
+    from microsoft_agents.activity import ActivityEventNames, ActivityTypes
+    from microsoft_agents.hosting.core.turn_context import TurnContext
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
+
 from microsoft.opentelemetry.a365.core.middleware.baggage_builder import BaggageBuilder
 
 from microsoft.opentelemetry.a365.hosting.scope_helpers.populate_baggage import populate
diff --git a/src/microsoft/opentelemetry/a365/hosting/middleware/observability_hosting_manager.py b/src/microsoft/opentelemetry/a365/hosting/middleware/observability_hosting_manager.py
index 0c8f9885..ce0be13c 100644
--- a/src/microsoft/opentelemetry/a365/hosting/middleware/observability_hosting_manager.py
+++ b/src/microsoft/opentelemetry/a365/hosting/middleware/observability_hosting_manager.py
@@ -8,7 +8,13 @@
 import logging
 from dataclasses import dataclass
 
-from microsoft_agents.hosting.core.middleware_set import MiddlewareSet
+try:
+    from microsoft_agents.hosting.core.middleware_set import MiddlewareSet
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
 
 from microsoft.opentelemetry.a365.hosting.middleware.baggage_middleware import BaggageMiddleware
 from microsoft.opentelemetry.a365.hosting.middleware.output_logging_middleware import OutputLoggingMiddleware
diff --git a/src/microsoft/opentelemetry/a365/hosting/middleware/output_logging_middleware.py b/src/microsoft/opentelemetry/a365/hosting/middleware/output_logging_middleware.py
index b5381848..ed7e1c1c 100644
--- a/src/microsoft/opentelemetry/a365/hosting/middleware/output_logging_middleware.py
+++ b/src/microsoft/opentelemetry/a365/hosting/middleware/output_logging_middleware.py
@@ -8,8 +8,15 @@
 import logging
 from collections.abc import Awaitable, Callable
 
-from microsoft_agents.activity import Activity
-from microsoft_agents.hosting.core.turn_context import TurnContext
+try:
+    from microsoft_agents.activity import Activity
+    from microsoft_agents.hosting.core.turn_context import TurnContext
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
+
 from microsoft.opentelemetry.a365.core.agent_details import AgentDetails
 from microsoft.opentelemetry.a365.constants import (
     CHANNEL_LINK_KEY,
diff --git a/src/microsoft/opentelemetry/a365/hosting/scope_helpers/populate_baggage.py b/src/microsoft/opentelemetry/a365/hosting/scope_helpers/populate_baggage.py
index f0e95bf1..d579586e 100644
--- a/src/microsoft/opentelemetry/a365/hosting/scope_helpers/populate_baggage.py
+++ b/src/microsoft/opentelemetry/a365/hosting/scope_helpers/populate_baggage.py
@@ -3,10 +3,18 @@
 
 from __future__ import annotations
 
+import logging
 from collections.abc import Iterator
 from typing import Any
 
-from microsoft_agents.hosting.core.turn_context import TurnContext
+try:
+    from microsoft_agents.hosting.core.turn_context import TurnContext
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
+
 from microsoft.opentelemetry.a365.core.middleware.baggage_builder import BaggageBuilder
 
 from microsoft.opentelemetry.a365.hosting.scope_helpers.utils import (
diff --git a/src/microsoft/opentelemetry/a365/hosting/scope_helpers/utils.py b/src/microsoft/opentelemetry/a365/hosting/scope_helpers/utils.py
index b5ab7a77..87bd0ccb 100644
--- a/src/microsoft/opentelemetry/a365/hosting/scope_helpers/utils.py
+++ b/src/microsoft/opentelemetry/a365/hosting/scope_helpers/utils.py
@@ -1,11 +1,20 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
+from __future__ import annotations
 
+import logging
 import json
 from collections.abc import Iterator
 from typing import Any
 
-from microsoft_agents.activity import Activity
+try:
+    from microsoft_agents.activity import Activity
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
+
 from microsoft.opentelemetry.a365.constants import (
     CHANNEL_LINK_KEY,
     CHANNEL_NAME_KEY,
diff --git a/src/microsoft/opentelemetry/a365/hosting/token_cache_helpers/agent_token_cache.py b/src/microsoft/opentelemetry/a365/hosting/token_cache_helpers/agent_token_cache.py
index 13ad2bae..a37a186f 100644
--- a/src/microsoft/opentelemetry/a365/hosting/token_cache_helpers/agent_token_cache.py
+++ b/src/microsoft/opentelemetry/a365/hosting/token_cache_helpers/agent_token_cache.py
@@ -11,8 +11,14 @@
 from dataclasses import dataclass
 from threading import Lock
 
-from microsoft_agents.hosting.core.app.oauth.authorization import Authorization
-from microsoft_agents.hosting.core.turn_context import TurnContext
+try:
+    from microsoft_agents.hosting.core.app.oauth.authorization import Authorization
+    from microsoft_agents.hosting.core.turn_context import TurnContext
+except ImportError:
+    logging.getLogger(__name__).error(
+        "microsoft.opentelemetry.a365.hosting requires the agents SDK. Install the "
+        "packages with `pip install microsoft-opentelemetry[hosting]`.",
+    )
 
 logger = logging.getLogger(__name__)
 
diff --git a/tests/a365/hosting/middleware/test_baggage_middleware.py b/tests/a365/hosting/middleware/test_baggage_middleware.py
index cd8dca1c..34be3acf 100644
--- a/tests/a365/hosting/middleware/test_baggage_middleware.py
+++ b/tests/a365/hosting/middleware/test_baggage_middleware.py
@@ -1,11 +1,16 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 import json
 from typing import Any
 from unittest.mock import MagicMock
 
-import pytest
 from microsoft_agents.activity import (
     Activity,
     ActivityEventNames,
diff --git a/tests/a365/hosting/middleware/test_observability_hosting_manager.py b/tests/a365/hosting/middleware/test_observability_hosting_manager.py
index 1c3c200e..422286ce 100644
--- a/tests/a365/hosting/middleware/test_observability_hosting_manager.py
+++ b/tests/a365/hosting/middleware/test_observability_hosting_manager.py
@@ -1,9 +1,14 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 from unittest.mock import MagicMock
 
-import pytest
 from microsoft.opentelemetry.a365.hosting.middleware.baggage_middleware import (
     BaggageMiddleware,
 )
diff --git a/tests/a365/hosting/middleware/test_output_logging_middleware.py b/tests/a365/hosting/middleware/test_output_logging_middleware.py
index a17ac1ef..7b40bfbc 100644
--- a/tests/a365/hosting/middleware/test_output_logging_middleware.py
+++ b/tests/a365/hosting/middleware/test_output_logging_middleware.py
@@ -1,9 +1,14 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 from unittest.mock import AsyncMock, MagicMock, patch
 
-import pytest
 from microsoft_agents.activity import (
     Activity,
     ChannelAccount,
diff --git a/tests/a365/hosting/scope_helpers/test_populate_baggage.py b/tests/a365/hosting/scope_helpers/test_populate_baggage.py
index 4e90f0c4..d3ce5fc3 100644
--- a/tests/a365/hosting/scope_helpers/test_populate_baggage.py
+++ b/tests/a365/hosting/scope_helpers/test_populate_baggage.py
@@ -1,6 +1,12 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 from unittest.mock import MagicMock
 
 from microsoft_agents.activity import Activity, ChannelAccount, ConversationAccount
diff --git a/tests/a365/hosting/scope_helpers/test_populate_invoke_agent_scope.py b/tests/a365/hosting/scope_helpers/test_populate_invoke_agent_scope.py
index 102843cc..c50a7f6a 100644
--- a/tests/a365/hosting/scope_helpers/test_populate_invoke_agent_scope.py
+++ b/tests/a365/hosting/scope_helpers/test_populate_invoke_agent_scope.py
@@ -1,10 +1,15 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 import os
 from unittest.mock import MagicMock
 
-import pytest
 from microsoft_agents.activity import Activity, ChannelAccount, ConversationAccount
 from microsoft_agents.hosting.core import TurnContext
 from microsoft.opentelemetry.a365.core.agent_details import AgentDetails
diff --git a/tests/a365/hosting/scope_helpers/test_scope_helper_utils.py b/tests/a365/hosting/scope_helpers/test_scope_helper_utils.py
index 8d0ee845..d4582aee 100644
--- a/tests/a365/hosting/scope_helpers/test_scope_helper_utils.py
+++ b/tests/a365/hosting/scope_helpers/test_scope_helper_utils.py
@@ -1,6 +1,11 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+import pytest
+
+pytest.importorskip("microsoft_agents.activity")
+
+# pylint: disable=wrong-import-position
 from microsoft_agents.activity import Activity, ChannelAccount, ConversationAccount
 from microsoft.opentelemetry.a365.core.constants import (
     CHANNEL_LINK_KEY,
diff --git a/tests/a365/hosting/token_cache_helpers/test_agent_token_cache.py b/tests/a365/hosting/token_cache_helpers/test_agent_token_cache.py
index 90130699..af0ac9a1 100644
--- a/tests/a365/hosting/token_cache_helpers/test_agent_token_cache.py
+++ b/tests/a365/hosting/token_cache_helpers/test_agent_token_cache.py
@@ -3,10 +3,14 @@
 
 """Tests for AgenticTokenCache and AgenticTokenStruct."""
 
+import pytest
+
+pytest.importorskip("microsoft_agents.hosting.core")
+
+# pylint: disable=wrong-import-position
 import threading
 from unittest.mock import AsyncMock, MagicMock
 
-import pytest
 from microsoft_agents.hosting.core.app.oauth.authorization import Authorization
 from microsoft_agents.hosting.core.turn_context import TurnContext
 from microsoft.opentelemetry.a365.hosting.token_cache_helpers import (