diff --git a/packages/toolbox-core/pyproject.toml b/packages/toolbox-core/pyproject.toml
index ee8a5f73..e9ee66f1 100644
--- a/packages/toolbox-core/pyproject.toml
+++ b/packages/toolbox-core/pyproject.toml
@@ -46,6 +46,8 @@ test = [
     "pytest==8.3.5",
     "pytest-aioresponses==0.3.0",
     "pytest-asyncio==0.25.3",
+    "google-cloud-secret-manager==2.23.2",
+    "google-cloud-storage==3.1.0",
 ]
 [build-system]
 requires = ["setuptools"]
diff --git a/packages/toolbox-core/tests/conftest.py b/packages/toolbox-core/tests/conftest.py
new file mode 100644
index 00000000..e579f843
--- /dev/null
+++ b/packages/toolbox-core/tests/conftest.py
@@ -0,0 +1,166 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Contains pytest fixtures that are accessible from all
+files present in the same directory."""
+
+from __future__ import annotations
+
+import os
+import platform
+import subprocess
+import tempfile
+import time
+from typing import Generator
+
+import google
+import pytest_asyncio
+from google.auth import compute_engine
+from google.cloud import secretmanager, storage
+
+
+#### Define Utility Functions
+def get_env_var(key: str) -> str:
+    """Gets environment variables."""
+    value = os.environ.get(key)
+    if value is None:
+        raise ValueError(f"Must set env var {key}")
+    return value
+
+
+def access_secret_version(
+    project_id: str, secret_id: str, version_id: str = "latest"
+) -> str:
+    """Accesses the payload of a given secret version from Secret Manager."""
+    client = secretmanager.SecretManagerServiceClient()
+    name = f"projects/{project_id}/secrets/{secret_id}/versions/{version_id}"
+    response = client.access_secret_version(request={"name": name})
+    return response.payload.data.decode("UTF-8")
+
+
+def create_tmpfile(content: str) -> str:
+    """Creates a temporary file with the given content."""
+    with tempfile.NamedTemporaryFile(delete=False, mode="w") as tmpfile:
+        tmpfile.write(content)
+        return tmpfile.name
+
+
+def download_blob(
+    bucket_name: str, source_blob_name: str, destination_file_name: str
+) -> None:
+    """Downloads a blob from a GCS bucket."""
+    storage_client = storage.Client()
+
+    bucket = storage_client.bucket(bucket_name)
+    blob = bucket.blob(source_blob_name)
+    blob.download_to_filename(destination_file_name)
+
+    print(f"Blob {source_blob_name} downloaded to {destination_file_name}.")
+
+
+def get_toolbox_binary_url(toolbox_version: str) -> str:
+    """Constructs the GCS path to the toolbox binary."""
+    os_system = platform.system().lower()
+    arch = (
+        "arm64" if os_system == "darwin" and platform.machine() == "arm64" else "amd64"
+    )
+    return f"v{toolbox_version}/{os_system}/{arch}/toolbox"
+
+
+def get_auth_token(client_id: str) -> str:
+    """Retrieves an authentication token"""
+    request = google.auth.transport.requests.Request()
+    credentials = compute_engine.IDTokenCredentials(
+        request=request,
+        target_audience=client_id,
+        use_metadata_identity_endpoint=True,
+    )
+    if not credentials.valid:
+        credentials.refresh(request)
+    return credentials.token
+
+
+#### Define Fixtures
+@pytest_asyncio.fixture(scope="session")
+def project_id() -> str:
+    return get_env_var("GOOGLE_CLOUD_PROJECT")
+
+
+@pytest_asyncio.fixture(scope="session")
+def toolbox_version() -> str:
+    return get_env_var("TOOLBOX_VERSION")
+
+
+@pytest_asyncio.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(
+        project_id=project_id, secret_id="sdk_testing_tools"
+    )
+    tools_file_path = create_tmpfile(tools_manifest)
+    yield tools_file_path
+    os.remove(tools_file_path)
+
+
+@pytest_asyncio.fixture(scope="session")
+def auth_token1(project_id: str) -> str:
+    client_id = access_secret_version(
+        project_id=project_id, secret_id="sdk_testing_client1"
+    )
+    return get_auth_token(client_id)
+
+
+@pytest_asyncio.fixture(scope="session")
+def auth_token2(project_id: str) -> str:
+    client_id = access_secret_version(
+        project_id=project_id, secret_id="sdk_testing_client2"
+    )
+    return get_auth_token(client_id)
+
+
+@pytest_asyncio.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...")
+    source_blob_name = get_toolbox_binary_url(toolbox_version)
+    download_blob("genai-toolbox", source_blob_name, "toolbox")
+    print("Toolbox binary downloaded successfully.")
+    try:
+        print("Opening toolbox server process...")
+        # Make toolbox executable
+        os.chmod("toolbox", 0o700)
+        # Run toolbox binary
+        toolbox_server = subprocess.Popen(
+            ["./toolbox", "--tools_file", tools_file_path]
+        )
+
+        # 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.")
+                break
+        else:
+            raise RuntimeError("Toolbox server failed to start after 5 retries.")
+    except subprocess.CalledProcessError as e:
+        print(e.stderr.decode("utf-8"))
+        print(e.stdout.decode("utf-8"))
+        raise RuntimeError(f"{e}\n\n{e.stderr.decode('utf-8')}") from e
+    yield
+
+    # Clean up toolbox server
+    toolbox_server.terminate()
+    toolbox_server.wait(timeout=5)
diff --git a/packages/toolbox-core/tests/test_e2e.py b/packages/toolbox-core/tests/test_e2e.py
new file mode 100644
index 00000000..43f4d0f8
--- /dev/null
+++ b/packages/toolbox-core/tests/test_e2e.py
@@ -0,0 +1,186 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import pytest
+import pytest_asyncio
+
+from toolbox_core.client import ToolboxClient
+from toolbox_core.tool import ToolboxTool
+
+
+# --- Shared Fixtures Defined at Module Level ---
+@pytest_asyncio.fixture(scope="function")
+async def toolbox():
+    """Creates a ToolboxClient instance shared by all tests in this module."""
+    toolbox = ToolboxClient("http://localhost:5000")
+    try:
+        yield toolbox
+    finally:
+        await toolbox.close()
+
+
+@pytest_asyncio.fixture(scope="function")
+async def get_n_rows_tool(toolbox: ToolboxClient) -> ToolboxTool:
+    """Load the 'get-n-rows' tool using the shared toolbox client."""
+    tool = await toolbox.load_tool("get-n-rows")
+    assert tool.__name__ == "get-n-rows"
+    return tool
+
+
+@pytest.mark.asyncio
+@pytest.mark.usefixtures("toolbox_server")
+class TestBasicE2E:
+    @pytest.mark.parametrize(
+        "toolset_name, expected_length, expected_tools",
+        [
+            ("my-toolset", 1, ["get-row-by-id"]),
+            ("my-toolset-2", 2, ["get-n-rows", "get-row-by-id"]),
+        ],
+    )
+    async def test_load_toolset_specific(
+        self,
+        toolbox: ToolboxClient,
+        toolset_name: str,
+        expected_length: int,
+        expected_tools: list[str],
+    ):
+        """Load a specific toolset"""
+        toolset = await toolbox.load_toolset(toolset_name)
+        assert len(toolset) == expected_length
+        tool_names = {tool.__name__ for tool in toolset}
+        assert tool_names == set(expected_tools)
+
+    async def test_run_tool(self, get_n_rows_tool: ToolboxTool):
+        """Invoke a tool."""
+        response = await get_n_rows_tool(num_rows="2")
+
+        assert isinstance(response, str)
+        assert "row1" in response
+        assert "row2" in response
+        assert "row3" not in response
+
+    async def test_run_tool_missing_params(self, get_n_rows_tool: ToolboxTool):
+        """Invoke a tool with missing params."""
+        with pytest.raises(TypeError, match="missing a required argument: 'num_rows'"):
+            await get_n_rows_tool()
+
+    async def test_run_tool_wrong_param_type(self, get_n_rows_tool: ToolboxTool):
+        """Invoke a tool with wrong param type."""
+        with pytest.raises(
+            Exception,
+            match='provided parameters were invalid: unable to parse value for "num_rows": .* not type "string"',
+        ):
+            await get_n_rows_tool(num_rows=2)
+
+
+@pytest.mark.asyncio
+@pytest.mark.usefixtures("toolbox_server")
+class TestBindParams:
+    async def test_bind_params(
+        self, toolbox: ToolboxClient, get_n_rows_tool: ToolboxTool
+    ):
+        """Bind a param to an existing tool."""
+        new_tool = get_n_rows_tool.bind_parameters({"num_rows": "3"})
+        response = await new_tool()
+        assert isinstance(response, str)
+        assert "row1" in response
+        assert "row2" in response
+        assert "row3" in response
+        assert "row4" not in response
+
+    async def test_bind_params_callable(
+        self, toolbox: ToolboxClient, get_n_rows_tool: ToolboxTool
+    ):
+        """Bind a callable param to an existing tool."""
+        new_tool = get_n_rows_tool.bind_parameters({"num_rows": lambda: "3"})
+        response = await new_tool()
+        assert isinstance(response, str)
+        assert "row1" in response
+        assert "row2" in response
+        assert "row3" in response
+        assert "row4" not in response
+
+
+@pytest.mark.asyncio
+@pytest.mark.usefixtures("toolbox_server")
+class TestAuth:
+    async def test_run_tool_unauth_with_auth(
+        self, toolbox: ToolboxClient, auth_token2: str
+    ):
+        """Tests running a tool that doesn't require auth, with auth provided."""
+        tool = await toolbox.load_tool(
+            "get-row-by-id", auth_token_getters={"my-test-auth": lambda: auth_token2}
+        )
+        response = await tool(id="2")
+        assert "row2" in response
+
+    async def test_run_tool_no_auth(self, toolbox: ToolboxClient):
+        """Tests running a tool requiring auth without providing auth."""
+        tool = await toolbox.load_tool("get-row-by-id-auth")
+        with pytest.raises(
+            Exception,
+            match="tool invocation not authorized. Please make sure your specify correct auth headers",
+        ):
+            await tool(id="2")
+
+    async def test_run_tool_wrong_auth(self, toolbox: ToolboxClient, auth_token2: str):
+        """Tests running a tool with incorrect auth. The tool
+        requires a different authentication than the one provided."""
+        tool = await toolbox.load_tool("get-row-by-id-auth")
+        auth_tool = tool.add_auth_token_getters({"my-test-auth": lambda: auth_token2})
+        with pytest.raises(
+            Exception,
+            match="tool invocation not authorized",
+        ):
+            await auth_tool(id="2")
+
+    async def test_run_tool_auth(self, toolbox: ToolboxClient, auth_token1: str):
+        """Tests running a tool with correct auth."""
+        tool = await toolbox.load_tool("get-row-by-id-auth")
+        auth_tool = tool.add_auth_token_getters({"my-test-auth": lambda: auth_token1})
+        response = await auth_tool(id="2")
+        assert "row2" in response
+
+    async def test_run_tool_param_auth_no_auth(self, toolbox: ToolboxClient):
+        """Tests running a tool with a param requiring auth, without auth."""
+        tool = await toolbox.load_tool("get-row-by-email-auth")
+        with pytest.raises(
+            Exception,
+            match="One or more of the following authn services are required to invoke this tool: my-test-auth",
+        ):
+            await tool()
+
+    async def test_run_tool_param_auth(self, toolbox: ToolboxClient, auth_token1: str):
+        """Tests running a tool with a param requiring auth, with correct auth."""
+        tool = await toolbox.load_tool(
+            "get-row-by-email-auth",
+            auth_token_getters={"my-test-auth": lambda: auth_token1},
+        )
+        response = await tool()
+        assert "row4" in response
+        assert "row5" in response
+        assert "row6" in response
+
+    async def test_run_tool_param_auth_no_field(
+        self, toolbox: ToolboxClient, auth_token1: str
+    ):
+        """Tests running a tool with a param requiring auth, with insufficient auth."""
+        tool = await toolbox.load_tool(
+            "get-row-by-content-auth",
+            auth_token_getters={"my-test-auth": lambda: auth_token1},
+        )
+        with pytest.raises(
+            Exception,
+            match="no field named row_data in claims",
+        ):
+            await tool()