diff --git a/packages/toolbox-adk/integration.cloudbuild.yaml b/packages/toolbox-adk/integration.cloudbuild.yaml
index 8d8b5678f..353bad129 100644
--- a/packages/toolbox-adk/integration.cloudbuild.yaml
+++ b/packages/toolbox-adk/integration.cloudbuild.yaml
@@ -50,5 +50,5 @@ options:
 substitutions:
   _VERSION: '3.13'
   # Default values (can be overridden by triggers)
-  _TOOLBOX_VERSION: '1.5.0'
+  _TOOLBOX_VERSION: '1.6.0'
   _TOOLBOX_MANIFEST_VERSION: '34'
diff --git a/packages/toolbox-adk/pyproject.toml b/packages/toolbox-adk/pyproject.toml
index 3ad5c35e4..54b9a2002 100644
--- a/packages/toolbox-adk/pyproject.toml
+++ b/packages/toolbox-adk/pyproject.toml
@@ -40,7 +40,8 @@ test = [
     "pytest==9.0.3",
     "pytest-asyncio==1.4.0",
     "pytest-cov==7.1.0",
-    "pytest-mock==3.15.1"
+    "pytest-mock==3.15.1",
+    "numpy<2", # Pinned to <2 to prevent mypy syntax errors on python 3.10 with numpy 2.x stubs,
 ]
 
 # Tells setuptools that packages are under the 'src' directory
diff --git a/packages/toolbox-adk/tests/integration/conftest.py b/packages/toolbox-adk/tests/integration/conftest.py
index 7a0346c3a..5c672547a 100644
--- a/packages/toolbox-adk/tests/integration/conftest.py
+++ b/packages/toolbox-adk/tests/integration/conftest.py
@@ -25,10 +25,13 @@
 from typing import Generator
 
 import google
-import pytest_asyncio
+import pytest
 from google.auth import compute_engine
 from google.cloud import secretmanager, storage
 
+TOOLBOX_SERVER_URL_STABLE = "http://localhost:5000"
+TOOLBOX_SERVER_URL_DRAFT = "http://localhost:5001"
+
 
 #### Define Utility Functions
 def get_env_var(key: str) -> str:
@@ -92,17 +95,17 @@ def get_auth_token(client_id: str) -> str:
 
 
 #### Define Fixtures
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def project_id() -> str:
     return get_env_var("GOOGLE_CLOUD_PROJECT")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_version() -> str:
     return get_env_var("TOOLBOX_VERSION")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def tools_file_path(project_id: str) -> Generator[str]:
     """Provides a temporary file path containing the tools manifest."""
     if os.environ.get("TEST_MOCK_GCP"):
@@ -122,7 +125,7 @@ def tools_file_path(project_id: str) -> Generator[str]:
     os.remove(tools_file_path)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token1(project_id: str) -> str:
     if os.environ.get("TEST_MOCK_GCP"):
         return "mock-token-1"
@@ -132,7 +135,7 @@ def auth_token1(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token2(project_id: str) -> str:
     if os.environ.get("TEST_MOCK_GCP"):
         return "mock-token-2"
@@ -142,7 +145,7 @@ def auth_token2(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None]:
     """Starts the toolbox server as a subprocess."""
     if os.environ.get("TEST_MOCK_GCP"):
@@ -159,20 +162,30 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
         # Make toolbox executable
         os.chmod("toolbox", 0o700)
         # Run toolbox binary
-        toolbox_server = subprocess.Popen(
-            ["./toolbox", "--tools-file", tools_file_path]
+        toolbox_server_1 = subprocess.Popen(
+            ["./toolbox", "--port", "5000", "--tools-file", tools_file_path]
+        )
+        toolbox_server_2 = subprocess.Popen(
+            [
+                "./toolbox",
+                "--port",
+                "5001",
+                "--tools-file",
+                tools_file_path,
+                "--enable-draft-specs",
+            ]
         )
 
         # Wait for server to start
         # Retry logic with a timeout
         for _ in range(5):  # retries
             time.sleep(2)
-            print("Checking if toolbox is successfully started...")
-            if toolbox_server.poll() is None:
-                print("Toolbox server started successfully.")
+            print("Checking if both toolbox servers are successfully started...")
+            if toolbox_server_1.poll() is None and toolbox_server_2.poll() is None:
+                print("Toolbox servers started successfully.")
                 break
         else:
-            raise RuntimeError("Toolbox server failed to start after 5 retries.")
+            raise RuntimeError("Toolbox servers failed to start after 5 retries.")
     except subprocess.CalledProcessError as e:
         print(e.stderr.decode("utf-8"))
         print(e.stdout.decode("utf-8"))
@@ -180,5 +193,31 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
     yield
 
     # Clean up toolbox server
-    toolbox_server.terminate()
-    toolbox_server.wait(timeout=5)
+    toolbox_server_1.terminate()
+    toolbox_server_2.terminate()
+    toolbox_server_1.wait(timeout=5)
+    toolbox_server_2.wait(timeout=5)
+
+
+@pytest.fixture(
+    params=[TOOLBOX_SERVER_URL_STABLE, TOOLBOX_SERVER_URL_DRAFT], scope="session"
+)
+def toolbox_server_url(request) -> str:
+    return request.param
+
+
+@pytest.fixture()
+def patch_toolbox_client_url(toolbox_server_url):
+    from toolbox_adk.toolset import ToolboxToolset
+
+    original_init = ToolboxToolset.__init__
+
+    def new_init(self, server_url=TOOLBOX_SERVER_URL_STABLE, *args, **kwargs):
+        if server_url == TOOLBOX_SERVER_URL_STABLE:
+            server_url = toolbox_server_url
+        original_init(self, server_url, *args, **kwargs)
+
+    from unittest.mock import patch
+
+    with patch.object(ToolboxToolset, "__init__", new_init, create=True):
+        yield
diff --git a/packages/toolbox-adk/tests/integration/test_integration.py b/packages/toolbox-adk/tests/integration/test_integration.py
index 780b66d38..0f8a88466 100644
--- a/packages/toolbox-adk/tests/integration/test_integration.py
+++ b/packages/toolbox-adk/tests/integration/test_integration.py
@@ -33,6 +33,8 @@
 
 from toolbox_adk import CredentialStrategy, ToolboxTool, ToolboxToolset
 
+TOOLBOX_SERVER_URL = "http://localhost:5000"
+
 # Ensure TOOLBOX_VERSION is set for the fixture
 if "TOOLBOX_VERSION" not in os.environ:
     os.environ["TOOLBOX_VERSION"] = "0.0.1"  # Use a valid version or mock
@@ -50,7 +52,7 @@ async def test_load_toolset_and_run(self):
         # Auth: TOOLBOX_IDENTITY for simplicity in this local test as we don't have ADK identity setup.
 
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -84,7 +86,7 @@ async def test_load_toolset_and_run(self):
     async def test_load_toolset_with_default_protocol(self):
         """Test initializing toolset with default protocol (MCP)."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -108,7 +110,7 @@ async def test_load_toolset_with_default_protocol(self):
     async def test_load_toolset_with_explicit_protocol(self):
         """Test initializing toolset with specific protocol (MCP_v20251125)."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.toolbox_identity(),
             protocol=Protocol.MCP_v20251125,
@@ -132,7 +134,7 @@ async def test_load_toolset_with_explicit_protocol(self):
 
     async def test_partial_loading_by_names(self):
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -152,7 +154,7 @@ async def test_partial_loading_by_names(self):
     async def test_bound_params_e2e(self):
         # Test binding param at toolset level
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             bound_params={"num_rows": "2"},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -168,7 +170,7 @@ async def test_bound_params_e2e(self):
 
     async def test_3lo_flow_simulation(self):
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             # Load a specific tool that we know the arguments for
             tool_names=["get-n-rows"],
             credentials=CredentialStrategy.user_identity(
@@ -265,7 +267,7 @@ async def test_3lo_flow_simulation(self):
     async def test_manual_token_integration(self):
         """Test the MANUAL_TOKEN strategy."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.manual_token(token="fake-manual-token"),
         )
@@ -284,7 +286,7 @@ async def test_manual_credentials_integration(self):
         mock_creds.token = "fake-creds-token"
 
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.manual_credentials(credentials=mock_creds),
         )
@@ -297,7 +299,7 @@ async def test_manual_credentials_integration(self):
     async def test_api_key_integration(self):
         """Test the API_KEY strategy."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=CredentialStrategy.api_key(key="my-key", header_name="x-foo"),
         )
@@ -333,7 +335,7 @@ async def test_adk_integration_optional_params(self):
 
         # 3. Use in Toolset
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             credentials=strategy,
         )
@@ -357,7 +359,7 @@ async def test_header_collision(self):
         creds_token = "Bearer strategy-token"
 
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name="my-toolset",
             additional_headers={"Authorization": manual_override},
             credentials=CredentialStrategy.manual_token(token="strategy-token"),
@@ -391,7 +393,7 @@ async def test_load_toolset_specific(
     ):
         """Load a specific toolset"""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             toolset_name=toolset_name,
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -406,7 +408,7 @@ async def test_load_toolset_specific(
     async def test_load_toolset_default(self):
         """Load the default toolset, i.e. all tools."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             credentials=CredentialStrategy.toolbox_identity(),
         )
         try:
@@ -429,7 +431,7 @@ async def test_load_toolset_default(self):
     async def test_run_tool(self):
         """Invoke a tool."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -451,7 +453,7 @@ async def test_run_tool(self):
     async def test_run_tool_missing_params(self):
         """Invoke a tool with missing params."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -470,7 +472,7 @@ async def test_run_tool_missing_params(self):
     async def test_run_tool_wrong_param_type(self):
         """Invoke a tool with wrong param type."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -494,7 +496,7 @@ class TestBindParams:
     async def test_bind_params(self):
         """Bind a param to an existing tool."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             bound_params={"num_rows": "3"},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -516,7 +518,7 @@ async def test_bind_params(self):
     async def test_bind_params_callable(self):
         """Bind a callable param to an existing tool."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-n-rows"],
             bound_params={"num_rows": lambda: "3"},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -542,7 +544,7 @@ class TestAuth:
     async def test_run_tool_unauth_with_auth(self, auth_token2: str):
         """Tests running a tool that doesn't require auth, with auth provided."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id"],
             auth_token_getters={"my-test-auth": lambda: auth_token2},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -559,7 +561,7 @@ async def test_run_tool_unauth_with_auth(self, auth_token2: str):
     async def test_run_multiple_tools_unauth_with_auth(self, auth_token2: str):
         """Tests running multiple tools that don't require auth, verifying formatting of tool lists."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id", "search-rows"],
             auth_token_getters={"my-test-auth": lambda: auth_token2},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -576,7 +578,7 @@ async def test_run_multiple_tools_unauth_with_auth(self, auth_token2: str):
     async def test_run_multiple_tools_partial_auth_usage(self, auth_token2: str):
         """Tests that when some tokens are used and some aren't across diverse tools, only the truly unused tokens appear in the error."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=[
                 "get-row-by-id-auth",
                 "search-rows",
@@ -601,7 +603,7 @@ async def test_run_tool_no_auth(self):
         """Tests running a tool requiring auth without providing auth."""
         # Note: We load it without auth getters. Invocation should fail.
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id-auth"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -621,7 +623,7 @@ async def test_run_tool_no_auth(self):
     async def test_run_tool_wrong_auth(self, auth_token2: str):
         """Tests running a tool with incorrect auth."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id-auth"],
             auth_token_getters={"my-test-auth": lambda: auth_token2},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -642,7 +644,7 @@ async def test_run_tool_wrong_auth(self, auth_token2: str):
     async def test_run_tool_auth(self, auth_token1: str):
         """Tests running a tool with correct auth."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id-auth"],
             auth_token_getters={"my-test-auth": lambda: auth_token1},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -664,7 +666,7 @@ async def get_token_asynchronously():
             return auth_token1
 
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["get-row-by-id-auth"],
             auth_token_getters={"my-test-auth": get_token_asynchronously},
             credentials=CredentialStrategy.toolbox_identity(),
@@ -690,7 +692,7 @@ class TestOptionalParams:
     async def test_run_tool_with_optional_params_omitted(self):
         """Invoke a tool providing only the required parameter."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["search-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -709,7 +711,7 @@ async def test_run_tool_with_optional_params_omitted(self):
     async def test_run_tool_with_all_valid_params(self):
         """Invoke a tool providing all parameters."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["search-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -729,7 +731,7 @@ async def test_run_tool_with_all_valid_params(self):
     async def test_run_tool_with_missing_required_param(self):
         """Invoke a tool without its required parameter."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["search-rows"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -754,7 +756,7 @@ class TestMapParams:
     async def test_run_tool_with_map_params(self):
         """Invoke a tool with valid map parameters."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["process-data"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
@@ -785,7 +787,7 @@ async def test_run_tool_with_map_params(self):
     async def test_run_tool_with_wrong_map_value_type(self):
         """Invoke a tool with a map parameter having the wrong value type."""
         toolset = ToolboxToolset(
-            server_url="http://localhost:5000",
+            server_url=TOOLBOX_SERVER_URL,
             tool_names=["process-data"],
             credentials=CredentialStrategy.toolbox_identity(),
         )
diff --git a/packages/toolbox-core/integration.cloudbuild.yaml b/packages/toolbox-core/integration.cloudbuild.yaml
index 17e388483..3dc6141ba 100644
--- a/packages/toolbox-core/integration.cloudbuild.yaml
+++ b/packages/toolbox-core/integration.cloudbuild.yaml
@@ -45,5 +45,5 @@ options:
   logging: CLOUD_LOGGING_ONLY
 substitutions:
   _VERSION: '3.13'
-  _TOOLBOX_VERSION: '1.5.0'
+  _TOOLBOX_VERSION: '1.6.0'
   _TOOLBOX_MANIFEST_VERSION: '34'
diff --git a/packages/toolbox-core/pyproject.toml b/packages/toolbox-core/pyproject.toml
index 6c2bf1a6d..6e44e0a11 100644
--- a/packages/toolbox-core/pyproject.toml
+++ b/packages/toolbox-core/pyproject.toml
@@ -60,7 +60,8 @@ test = [
     "google-cloud-secret-manager==2.28.0",
     "google-cloud-storage==3.10.1",
     "aioresponses==0.7.8",
-    "toolbox-core[telemetry]"
+    "toolbox-core[telemetry]",
+    "numpy<2", # Pinned to <2 to prevent mypy syntax errors on python 3.10 with numpy 2.x stubs
 ]
 [build-system]
 requires = ["setuptools"]
diff --git a/packages/toolbox-core/tests/conftest.py b/packages/toolbox-core/tests/conftest.py
index 338d031c0..b78db9db6 100644
--- a/packages/toolbox-core/tests/conftest.py
+++ b/packages/toolbox-core/tests/conftest.py
@@ -25,10 +25,13 @@
 from typing import Generator
 
 import google
-import pytest_asyncio
+import pytest
 from google.auth import compute_engine
 from google.cloud import secretmanager, storage
 
+TOOLBOX_SERVER_URL_STABLE = "http://localhost:5000"
+TOOLBOX_SERVER_URL_DRAFT = "http://localhost:5001"
+
 
 #### Define Utility Functions
 def get_env_var(key: str) -> str:
@@ -92,17 +95,17 @@ def get_auth_token(client_id: str) -> str:
 
 
 #### Define Fixtures
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def project_id() -> str:
     return get_env_var("GOOGLE_CLOUD_PROJECT")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_version() -> str:
     return get_env_var("TOOLBOX_VERSION")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def tools_file_path(project_id: str) -> Generator[str]:
     """Provides a temporary file path containing the tools manifest."""
     tools_manifest = access_secret_version(
@@ -115,7 +118,7 @@ def tools_file_path(project_id: str) -> Generator[str]:
     os.remove(tools_file_path)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token1(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client1"
@@ -123,7 +126,7 @@ def auth_token1(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token2(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client2"
@@ -131,7 +134,7 @@ def auth_token2(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None]:
     """Starts the toolbox server as a subprocess."""
     print("Downloading toolbox binary from gcs bucket...")
@@ -143,20 +146,30 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
         # Make toolbox executable
         os.chmod("toolbox", 0o700)
         # Run toolbox binary
-        toolbox_server = subprocess.Popen(
-            ["./toolbox", "--tools-file", tools_file_path]
+        toolbox_server_1 = subprocess.Popen(
+            ["./toolbox", "--port", "5000", "--tools-file", tools_file_path]
+        )
+        toolbox_server_2 = subprocess.Popen(
+            [
+                "./toolbox",
+                "--port",
+                "5001",
+                "--tools-file",
+                tools_file_path,
+                "--enable-draft-specs",
+            ]
         )
 
         # Wait for server to start
         # Retry logic with a timeout
         for _ in range(5):  # retries
             time.sleep(2)
-            print("Checking if toolbox is successfully started...")
-            if toolbox_server.poll() is None:
-                print("Toolbox server started successfully.")
+            print("Checking if both toolbox servers are successfully started...")
+            if toolbox_server_1.poll() is None and toolbox_server_2.poll() is None:
+                print("Toolbox servers started successfully.")
                 break
         else:
-            raise RuntimeError("Toolbox server failed to start after 5 retries.")
+            raise RuntimeError("Toolbox servers failed to start after 5 retries.")
     except subprocess.CalledProcessError as e:
         print(e.stderr.decode("utf-8"))
         print(e.stdout.decode("utf-8"))
@@ -164,5 +177,39 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
     yield
 
     # Clean up toolbox server
-    toolbox_server.terminate()
-    toolbox_server.wait(timeout=5)
+    toolbox_server_1.terminate()
+    toolbox_server_2.terminate()
+    toolbox_server_1.wait(timeout=5)
+    toolbox_server_2.wait(timeout=5)
+
+
+@pytest.fixture(
+    params=[TOOLBOX_SERVER_URL_STABLE, TOOLBOX_SERVER_URL_DRAFT], scope="session"
+)
+def toolbox_server_url(request) -> str:
+    return request.param
+
+
+@pytest.fixture()
+def patch_toolbox_client_url(toolbox_server_url):
+    from toolbox_core.client import ToolboxClient
+    from toolbox_core.sync_client import ToolboxSyncClient
+
+    original_init = ToolboxClient.__init__
+    original_sync_init = ToolboxSyncClient.__init__
+
+    def new_init(self, url=TOOLBOX_SERVER_URL_STABLE, *args, **kwargs):
+        if url == TOOLBOX_SERVER_URL_STABLE:
+            url = toolbox_server_url
+        original_init(self, url, *args, **kwargs)
+
+    def new_sync_init(self, url=TOOLBOX_SERVER_URL_STABLE, *args, **kwargs):
+        if url == TOOLBOX_SERVER_URL_STABLE:
+            url = toolbox_server_url
+        original_sync_init(self, url, *args, **kwargs)
+
+    from unittest.mock import patch
+
+    with patch.object(ToolboxClient, "__init__", new_init, create=True):
+        with patch.object(ToolboxSyncClient, "__init__", new_sync_init, create=True):
+            yield
diff --git a/packages/toolbox-core/tests/test_e2e.py b/packages/toolbox-core/tests/test_e2e.py
index 0b926e178..9f1f6b01f 100644
--- a/packages/toolbox-core/tests/test_e2e.py
+++ b/packages/toolbox-core/tests/test_e2e.py
@@ -23,6 +23,8 @@
 from toolbox_core.protocol import Protocol
 from toolbox_core.tool import ToolboxTool
 
+pytestmark = pytest.mark.usefixtures("patch_toolbox_client_url")
+
 
 # --- Shared Fixtures Defined at Module Level ---
 @pytest_asyncio.fixture(scope="function")
diff --git a/packages/toolbox-core/tests/test_e2e_mcp.py b/packages/toolbox-core/tests/test_e2e_mcp.py
index c35695ffa..d9dc6a6cc 100644
--- a/packages/toolbox-core/tests/test_e2e_mcp.py
+++ b/packages/toolbox-core/tests/test_e2e_mcp.py
@@ -23,6 +23,8 @@
 from toolbox_core.protocol import Protocol
 from toolbox_core.tool import ToolboxTool
 
+pytestmark = pytest.mark.usefixtures("patch_toolbox_client_url")
+
 
 # TODO: Include draft versions in E2E integration tests once the server
 # supports SEP-2575 (stateless MCP / Request-Metadata).
@@ -100,20 +102,26 @@ async def test_run_tool_missing_params(self, get_n_rows_tool: ToolboxTool):
         with pytest.raises(TypeError, match="missing a required argument: 'num_rows'"):
             await get_n_rows_tool()
 
-    async def test_protocol_fallback_e2e(self):
+    async def test_protocol_fallback_e2e(self, toolbox_server_url):
         """Tests that a client using MCP_LATEST can fallback to an older protocol against a server that doesn't support the latest version."""
         # The E2E server currently does not support DRAFT 2026, so this will trigger a fallback.
         async with ToolboxClient(
-            "http://localhost:5000", protocol=Protocol.MCP_LATEST
+            toolbox_server_url, protocol=Protocol.MCP_LATEST
         ) as client:
             tool = await client.load_tool("get-n-rows")
             response = await tool(num_rows="1")
             assert "row1" in response
             # Verify that fallback occurred by checking the transport's final protocol version
-            assert (
-                client._ToolboxClient__transport._protocol_version
-                != Protocol.MCP_LATEST.value
-            )
+            if "5000" in toolbox_server_url:
+                assert (
+                    client._ToolboxClient__transport._protocol_version
+                    != Protocol.MCP_LATEST.value
+                )
+            else:
+                assert (
+                    client._ToolboxClient__transport._protocol_version
+                    == Protocol.MCP_LATEST.value
+                )
 
     async def test_run_tool_wrong_param_type(self, get_n_rows_tool: ToolboxTool):
         """Invoke a tool with wrong param type."""
diff --git a/packages/toolbox-core/tests/test_sync_e2e.py b/packages/toolbox-core/tests/test_sync_e2e.py
index a306cedc2..38b90b131 100644
--- a/packages/toolbox-core/tests/test_sync_e2e.py
+++ b/packages/toolbox-core/tests/test_sync_e2e.py
@@ -17,6 +17,8 @@
 from toolbox_core.sync_client import ToolboxSyncClient
 from toolbox_core.sync_tool import ToolboxSyncTool
 
+pytestmark = pytest.mark.usefixtures("patch_toolbox_client_url")
+
 
 # --- Shared Fixtures Defined at Module Level ---
 @pytest.fixture(scope="module")
diff --git a/packages/toolbox-core/tests/test_tool.py b/packages/toolbox-core/tests/test_tool.py
index 1b23db3ae..9e5ad85b2 100644
--- a/packages/toolbox-core/tests/test_tool.py
+++ b/packages/toolbox-core/tests/test_tool.py
@@ -409,9 +409,14 @@ def test_tool_init_basic(http_session, sample_tool_params, sample_tool_descripti
             bound_params={},
             client_headers={},
         )
+    relevant_warnings = [
+        w
+        for w in record
+        if not issubclass(w.category, (ResourceWarning, DeprecationWarning))
+    ]
     assert (
-        len(record) == 0
-    ), f"ToolboxTool instantiation unexpectedly warned: {[f'{w.category.__name__}: {w.message}' for w in record]}"
+        len(relevant_warnings) == 0
+    ), f"ToolboxTool instantiation unexpectedly warned: {[f'{w.category.__name__}: {w.message}' for w in relevant_warnings]}"
 
     assert tool_instance.__name__ == TEST_TOOL_NAME
     assert inspect.iscoroutinefunction(tool_instance.__call__)
diff --git a/packages/toolbox-langchain/integration.cloudbuild.yaml b/packages/toolbox-langchain/integration.cloudbuild.yaml
index 39a34b5fe..db9cbc135 100644
--- a/packages/toolbox-langchain/integration.cloudbuild.yaml
+++ b/packages/toolbox-langchain/integration.cloudbuild.yaml
@@ -49,5 +49,5 @@ options:
   logging: CLOUD_LOGGING_ONLY
 substitutions:
   _VERSION: '3.13'
-  _TOOLBOX_VERSION: '1.5.0'
+  _TOOLBOX_VERSION: '1.6.0'
   _TOOLBOX_MANIFEST_VERSION: '34'
diff --git a/packages/toolbox-langchain/pyproject.toml b/packages/toolbox-langchain/pyproject.toml
index 247fdbfab..76e0845a1 100644
--- a/packages/toolbox-langchain/pyproject.toml
+++ b/packages/toolbox-langchain/pyproject.toml
@@ -53,6 +53,7 @@ test = [
     "Pillow==12.2.0; python_version >= '3.10'",
     "google-cloud-secret-manager==2.28.0",
     "google-cloud-storage==3.10.1",
+    "numpy<2", # Pinned to <2 to prevent mypy syntax errors on python 3.10 with numpy 2.x stubs
 ]
 
 [build-system]
diff --git a/packages/toolbox-langchain/tests/conftest.py b/packages/toolbox-langchain/tests/conftest.py
index a1c87a7d8..05d9a175a 100644
--- a/packages/toolbox-langchain/tests/conftest.py
+++ b/packages/toolbox-langchain/tests/conftest.py
@@ -25,10 +25,13 @@
 from typing import Generator
 
 import google
-import pytest_asyncio
+import pytest
 from google.auth import compute_engine
 from google.cloud import secretmanager, storage
 
+TOOLBOX_SERVER_URL_STABLE = "http://localhost:5000"
+TOOLBOX_SERVER_URL_DRAFT = "http://localhost:5001"
+
 
 #### Define Utility Functions
 def get_env_var(key: str) -> str:
@@ -92,17 +95,17 @@ def get_auth_token(client_id: str) -> str:
 
 
 #### Define Fixtures
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def project_id() -> str:
     return get_env_var("GOOGLE_CLOUD_PROJECT")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_version() -> str:
     return get_env_var("TOOLBOX_VERSION")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def tools_file_path(project_id: str) -> Generator[str]:
     """Provides a temporary file path containing the tools manifest."""
     tools_manifest = access_secret_version(
@@ -115,7 +118,7 @@ def tools_file_path(project_id: str) -> Generator[str]:
     os.remove(tools_file_path)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token1(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client1"
@@ -123,7 +126,7 @@ def auth_token1(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token2(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client2"
@@ -131,7 +134,7 @@ def auth_token2(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None]:
     """Starts the toolbox server as a subprocess."""
     print("Downloading toolbox binary from gcs bucket...")
@@ -143,20 +146,30 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
         # Make toolbox executable
         os.chmod("toolbox", 0o700)
         # Run toolbox binary
-        toolbox_server = subprocess.Popen(
-            ["./toolbox", "--tools-file", tools_file_path]
+        toolbox_server_1 = subprocess.Popen(
+            ["./toolbox", "--port", "5000", "--tools-file", tools_file_path]
+        )
+        toolbox_server_2 = subprocess.Popen(
+            [
+                "./toolbox",
+                "--port",
+                "5001",
+                "--tools-file",
+                tools_file_path,
+                "--enable-draft-specs",
+            ]
         )
 
         # Wait for server to start
         # Retry logic with a timeout
         for _ in range(5):  # retries
-            time.sleep(2)
-            print("Checking if toolbox is successfully started...")
-            if toolbox_server.poll() is None:
-                print("Toolbox server started successfully.")
+            time.sleep(4)
+            print("Checking if both toolbox servers are successfully started...")
+            if toolbox_server_1.poll() is None and toolbox_server_2.poll() is None:
+                print("Toolbox servers started successfully.")
                 break
         else:
-            raise RuntimeError("Toolbox server failed to start after 5 retries.")
+            raise RuntimeError("Toolbox servers failed to start after 5 retries.")
     except subprocess.CalledProcessError as e:
         print(e.stderr.decode("utf-8"))
         print(e.stdout.decode("utf-8"))
@@ -164,5 +177,31 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
     yield
 
     # Clean up toolbox server
-    toolbox_server.terminate()
-    toolbox_server.wait()
+    toolbox_server_1.terminate()
+    toolbox_server_2.terminate()
+    toolbox_server_1.wait()
+    toolbox_server_2.wait()
+
+
+@pytest.fixture(
+    params=[TOOLBOX_SERVER_URL_STABLE, TOOLBOX_SERVER_URL_DRAFT], scope="session"
+)
+def toolbox_server_url(request) -> str:
+    return request.param
+
+
+@pytest.fixture()
+def patch_toolbox_client_url(toolbox_server_url):
+    from toolbox_core.client import ToolboxClient
+
+    original_init = ToolboxClient.__init__
+
+    def new_init(self, url=TOOLBOX_SERVER_URL_STABLE, *args, **kwargs):
+        if url == TOOLBOX_SERVER_URL_STABLE:
+            url = toolbox_server_url
+        original_init(self, url, *args, **kwargs)
+
+    from unittest.mock import patch
+
+    with patch.object(ToolboxClient, "__init__", new_init, create=True):
+        yield
diff --git a/packages/toolbox-langchain/tests/test_e2e.py b/packages/toolbox-langchain/tests/test_e2e.py
index 93fbd01ea..8291cf4f4 100644
--- a/packages/toolbox-langchain/tests/test_e2e.py
+++ b/packages/toolbox-langchain/tests/test_e2e.py
@@ -40,6 +40,10 @@
 
 from toolbox_langchain.client import ToolboxClient
 
+pytestmark = pytest.mark.usefixtures("patch_toolbox_client_url")
+
+TOOLBOX_SERVER_URL = "http://localhost:5000"
+
 
 @pytest.mark.asyncio
 @pytest.mark.usefixtures("toolbox_server")
@@ -47,7 +51,7 @@ class TestE2EClientAsync:
     @pytest.fixture(scope="function")
     def toolbox(self):
         """Provides a ToolboxClient instance for each test."""
-        toolbox = ToolboxClient("http://localhost:5000")
+        toolbox = ToolboxClient(TOOLBOX_SERVER_URL)
         return toolbox
 
     @pytest_asyncio.fixture(scope="function")
@@ -194,7 +198,7 @@ class TestE2EClientSync:
     @pytest.fixture(scope="session")
     def toolbox(self):
         """Provides a ToolboxClient instance for each test."""
-        toolbox = ToolboxClient("http://localhost:5000")
+        toolbox = ToolboxClient(TOOLBOX_SERVER_URL)
         return toolbox
 
     @pytest.fixture(scope="function")
diff --git a/packages/toolbox-llamaindex/integration.cloudbuild.yaml b/packages/toolbox-llamaindex/integration.cloudbuild.yaml
index 0d31e0d69..3a2e609aa 100644
--- a/packages/toolbox-llamaindex/integration.cloudbuild.yaml
+++ b/packages/toolbox-llamaindex/integration.cloudbuild.yaml
@@ -49,5 +49,5 @@ options:
   logging: CLOUD_LOGGING_ONLY
 substitutions:
   _VERSION: '3.13'
-  _TOOLBOX_VERSION: '1.5.0'
+  _TOOLBOX_VERSION: '1.6.0'
   _TOOLBOX_MANIFEST_VERSION: '34'
diff --git a/packages/toolbox-llamaindex/pyproject.toml b/packages/toolbox-llamaindex/pyproject.toml
index ec8107ead..fe801b2cc 100644
--- a/packages/toolbox-llamaindex/pyproject.toml
+++ b/packages/toolbox-llamaindex/pyproject.toml
@@ -53,6 +53,7 @@ test = [
     "Pillow==12.2.0; python_version >= '3.10'",
     "google-cloud-secret-manager==2.28.0",
     "google-cloud-storage==3.10.1",
+    "numpy<2", # Pinned to <2 to prevent mypy syntax errors on python 3.10 with numpy 2.x stubs
 ]
 
 [build-system]
diff --git a/packages/toolbox-llamaindex/tests/conftest.py b/packages/toolbox-llamaindex/tests/conftest.py
index c8a8fa5f9..fa9784f1f 100644
--- a/packages/toolbox-llamaindex/tests/conftest.py
+++ b/packages/toolbox-llamaindex/tests/conftest.py
@@ -25,10 +25,13 @@
 from typing import Generator
 
 import google
-import pytest_asyncio
+import pytest
 from google.auth import compute_engine
 from google.cloud import secretmanager, storage
 
+TOOLBOX_SERVER_URL_STABLE = "http://localhost:5000"
+TOOLBOX_SERVER_URL_DRAFT = "http://localhost:5001"
+
 
 #### Define Utility Functions
 def get_env_var(key: str) -> str:
@@ -92,17 +95,17 @@ def get_auth_token(client_id: str) -> str:
 
 
 #### Define Fixtures
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def project_id() -> str:
     return get_env_var("GOOGLE_CLOUD_PROJECT")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_version() -> str:
     return get_env_var("TOOLBOX_VERSION")
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def tools_file_path(project_id: str) -> Generator[str]:
     """Provides a temporary file path containing the tools manifest."""
     tools_manifest = access_secret_version(
@@ -115,7 +118,7 @@ def tools_file_path(project_id: str) -> Generator[str]:
     os.remove(tools_file_path)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token1(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client1"
@@ -123,7 +126,7 @@ def auth_token1(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def auth_token2(project_id: str) -> str:
     client_id = access_secret_version(
         project_id=project_id, secret_id="sdk_testing_client2"
@@ -131,7 +134,7 @@ def auth_token2(project_id: str) -> str:
     return get_auth_token(client_id)
 
 
-@pytest_asyncio.fixture(scope="session")
+@pytest.fixture(scope="session")
 def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None]:
     """Starts the toolbox server as a subprocess."""
     print("Downloading toolbox binary from gcs bucket...")
@@ -143,20 +146,30 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
         # Make toolbox executable
         os.chmod("toolbox", 0o700)
         # Run toolbox binary
-        toolbox_server = subprocess.Popen(
-            ["./toolbox", "--tools-file", tools_file_path]
+        toolbox_server_1 = subprocess.Popen(
+            ["./toolbox", "--port", "5000", "--tools-file", tools_file_path]
+        )
+        toolbox_server_2 = subprocess.Popen(
+            [
+                "./toolbox",
+                "--port",
+                "5001",
+                "--tools-file",
+                tools_file_path,
+                "--enable-draft-specs",
+            ]
         )
 
         # Wait for server to start
         # Retry logic with a timeout
         for _ in range(5):  # retries
             time.sleep(4)
-            print("Checking if toolbox is successfully started...")
-            if toolbox_server.poll() is None:
-                print("Toolbox server started successfully.")
+            print("Checking if both toolbox servers are successfully started...")
+            if toolbox_server_1.poll() is None and toolbox_server_2.poll() is None:
+                print("Toolbox servers started successfully.")
                 break
         else:
-            raise RuntimeError("Toolbox server failed to start after 5 retries.")
+            raise RuntimeError("Toolbox servers failed to start after 5 retries.")
     except subprocess.CalledProcessError as e:
         print(e.stderr.decode("utf-8"))
         print(e.stdout.decode("utf-8"))
@@ -164,5 +177,31 @@ def toolbox_server(toolbox_version: str, tools_file_path: str) -> Generator[None
     yield
 
     # Clean up toolbox server
-    toolbox_server.terminate()
-    toolbox_server.wait()
+    toolbox_server_1.terminate()
+    toolbox_server_2.terminate()
+    toolbox_server_1.wait()
+    toolbox_server_2.wait()
+
+
+@pytest.fixture(
+    params=[TOOLBOX_SERVER_URL_STABLE, TOOLBOX_SERVER_URL_DRAFT], scope="session"
+)
+def toolbox_server_url(request) -> str:
+    return request.param
+
+
+@pytest.fixture()
+def patch_toolbox_client_url(toolbox_server_url):
+    from toolbox_core.client import ToolboxClient
+
+    original_init = ToolboxClient.__init__
+
+    def new_init(self, url=TOOLBOX_SERVER_URL_STABLE, *args, **kwargs):
+        if url == TOOLBOX_SERVER_URL_STABLE:
+            url = toolbox_server_url
+        original_init(self, url, *args, **kwargs)
+
+    from unittest.mock import patch
+
+    with patch.object(ToolboxClient, "__init__", new_init, create=True):
+        yield
diff --git a/packages/toolbox-llamaindex/tests/test_e2e.py b/packages/toolbox-llamaindex/tests/test_e2e.py
index e0cdba4cb..7664eeb32 100644
--- a/packages/toolbox-llamaindex/tests/test_e2e.py
+++ b/packages/toolbox-llamaindex/tests/test_e2e.py
@@ -40,6 +40,10 @@
 
 from toolbox_llamaindex.client import ToolboxClient
 
+pytestmark = pytest.mark.usefixtures("patch_toolbox_client_url")
+
+TOOLBOX_SERVER_URL = "http://localhost:5000"
+
 
 @pytest.mark.asyncio
 @pytest.mark.usefixtures("toolbox_server")
@@ -47,7 +51,7 @@ class TestE2EClientAsync:
     @pytest.fixture(scope="function")
     def toolbox(self):
         """Provides a ToolboxClient instance for each test."""
-        toolbox = ToolboxClient("http://localhost:5000")
+        toolbox = ToolboxClient(TOOLBOX_SERVER_URL)
         return toolbox
 
     @pytest_asyncio.fixture(scope="function")
@@ -194,7 +198,7 @@ class TestE2EClientSync:
     @pytest.fixture(scope="session")
     def toolbox(self):
         """Provides a ToolboxClient instance for each test."""
-        toolbox = ToolboxClient("http://localhost:5000")
+        toolbox = ToolboxClient(TOOLBOX_SERVER_URL)
         return toolbox
 
     @pytest.fixture(scope="function")