MCPToolset ignores auth_scheme/auth_credential during initialization and tool listing #2168
Description
Describe the bug
When passing auth_scheme and auth_credential to MCPToolset, the authentication is not performed during the MCP initialization and tool listing phases. This results in a failure when using authenticated MCP services.
To Reproduce
Steps to reproduce the behavior:
1.Install the MCP server:
pip install fastmcp
2.Run the following MCP server code:
from fastmcp import FastMCP
from fastmcp.server.auth import BearerAuthProvider
from fastmcp.server.auth.providers.bearer import RSAKeyPair
key_pair = RSAKeyPair.generate()
auth = BearerAuthProvider(
public_key=key_pair.public_key,
issuer="https://dev.example.com",
audience="my-dev-server"
)
token = key_pair.create_token(
subject="test_user",
issuer="https://dev.example.com"
)
print("token:", token) # paste the token to next
mcp = FastMCP(name="My MCP Server", auth=auth)
@mcp.tool
def real_time() -> str:
return "2025-07-24 12:30"
if __name__ == "__main__":
mcp.run(port=8080)
- Use the following ADK client code to access the server:
from google.adk.agents.llm_agent import LlmAgent
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPServerParams
from google.adk.tools.mcp_tool.mcp_toolset import MCPToolset
from google.adk.tools.openapi_tool.auth.auth_helpers import token_to_scheme_credential
token = "your paste token"
auth_scheme, auth_credential = token_to_scheme_credential(
"oauth2Token", "header", "Authorization", token
)
root_agent = LlmAgent(
model="gemini-2.0-flash",
name='Assistant',
instruction="""You are a professional assistant with access to real-time tool.""",
tools=[
MCPToolset(
connection_params=StreamableHTTPServerParams(
url='https://127.0.0.1:8080/mcp/',
),
auth_scheme=auth_scheme,
auth_credential=auth_credential
)
],
)
-
Run agent and ask any question.
-
See the error due to missing authentication.
Expected behavior
The MCPToolset should correctly apply the auth_scheme and auth_credential during the initialization and tool listing phases, ensuring authentication occurs as expected and the tool can be invoked successfully.
Screenshots
Desktop:
- OS: Mac OS
- Python version: python 3.11.9
- ADK version: v1.8.0
Model Information:
Model: gemini-2.0-flash
Additional context