diff --git a/tests/langsmith_tracing/conftest.py b/tests/langsmith_tracing/conftest.py
new file mode 100644
index 00000000..d66384f8
--- /dev/null
+++ b/tests/langsmith_tracing/conftest.py
@@ -0,0 +1,21 @@
+"""Shared fixtures for LangSmith tracing tests."""
+
+from unittest.mock import MagicMock
+
+import pytest
+
+
+@pytest.fixture
+def mock_ls_client() -> MagicMock:
+    """Return a mock ``langsmith.Client`` that never makes network calls.
+
+    The samples tests don't assert on trace output — the LangSmith plugin
+    just needs *some* client object to wire into the worker.  ``MagicMock``
+    auto-stubs every method the interceptor calls; the explicit ``session``
+    and ``tracing_queue`` stubs match what the langsmith library touches
+    internally.
+    """
+    client = MagicMock()
+    client.session = MagicMock()
+    client.tracing_queue = MagicMock()
+    return client
diff --git a/tests/langsmith_tracing/test_basic.py b/tests/langsmith_tracing/test_basic.py
index b5be2f35..cef49054 100644
--- a/tests/langsmith_tracing/test_basic.py
+++ b/tests/langsmith_tracing/test_basic.py
@@ -1,4 +1,5 @@
 import uuid
+from unittest.mock import MagicMock
 
 from temporalio import activity
 from temporalio.client import Client
@@ -10,7 +11,9 @@
 from langsmith_tracing.basic.workflows import BasicLLMWorkflow
 
 
-async def test_basic_workflow(client: Client, env: WorkflowEnvironment):
+async def test_basic_workflow(
+    client: Client, env: WorkflowEnvironment, mock_ls_client: MagicMock
+):
     expected_text = "Temporal is a durable execution platform."
 
     @activity.defn(name="call_openai")
@@ -22,7 +25,7 @@ async def mock_call_openai(request: OpenAIRequest) -> str:
         task_queue="test-langsmith-basic",
         workflows=[BasicLLMWorkflow],
         activities=[mock_call_openai],
-        plugins=[LangSmithPlugin()],
+        plugins=[LangSmithPlugin(client=mock_ls_client)],
     ):
         result = await client.execute_workflow(
             BasicLLMWorkflow.run,
diff --git a/tests/langsmith_tracing/test_chatbot.py b/tests/langsmith_tracing/test_chatbot.py
index 2febb654..88d98202 100644
--- a/tests/langsmith_tracing/test_chatbot.py
+++ b/tests/langsmith_tracing/test_chatbot.py
@@ -1,5 +1,6 @@
 import json
 import uuid
+from unittest.mock import MagicMock
 
 from temporalio import activity
 from temporalio.client import Client
@@ -27,7 +28,9 @@ def _make_function_call_response(
     )
 
 
-async def test_chatbot_save_note(client: Client, env: WorkflowEnvironment):
+async def test_chatbot_save_note(
+    client: Client, env: WorkflowEnvironment, mock_ls_client: MagicMock
+):
     """Test save_note tool call loop — save_note runs as a workflow method."""
     call_count = 0
 
@@ -47,7 +50,7 @@ async def mock_call_openai(request: OpenAIRequest) -> ChatResponse:
         task_queue="test-langsmith-chatbot",
         workflows=[ChatbotWorkflow],
         activities=[mock_call_openai],
-        plugins=[LangSmithPlugin()],
+        plugins=[LangSmithPlugin(client=mock_ls_client)],
     ):
         wf_handle = await client.start_workflow(
             ChatbotWorkflow.run,
@@ -68,8 +71,10 @@ async def mock_call_openai(request: OpenAIRequest) -> ChatResponse:
         assert result == "Session ended."
 
 
-async def test_chatbot_read_note(client: Client, env: WorkflowEnvironment):
-    """Test read_note tool call loop — read_note runs as a workflow method."""
+async def test_chatbot_read_note(
+    client: Client, env: WorkflowEnvironment, mock_ls_client: MagicMock
+):
+    """Test read_note tool call loop — saves a note first, then reads it back."""
     call_count = 0
 
     @activity.defn(name="call_openai")
@@ -97,7 +102,7 @@ async def mock_call_openai(request: OpenAIRequest) -> ChatResponse:
         task_queue="test-langsmith-chatbot-read",
         workflows=[ChatbotWorkflow],
         activities=[mock_call_openai],
-        plugins=[LangSmithPlugin()],
+        plugins=[LangSmithPlugin(client=mock_ls_client)],
     ):
         wf_handle = await client.start_workflow(
             ChatbotWorkflow.run,