[BUG] Remote MCP auth issue?

[hemanth]

Description

Error connecting to remote MCP which needs auth.

Steps to Reproduce

from crewai import Agent, Task, Crew
from crewai_tools import MCPServerAdapter
import sys # Import sys to access exception information

server_params = {
    "url": "https://mcp.paypal.com/sse",
    "headers": {
        "Authorization": "Bearer <Token>",
    }
}

try:
    with MCPServerAdapter(server_params) as tools:
        print("Available MCP Tools:", [tool.name for tool in tools])

        doc_agent = Agent(
            role="PayPal API Expert",
            goal="Find answers to questions about PayPal products and APIs using the available MCP tool.",
            backstory="A helpful assistant for PayPal documentation and API references.",
            tools=tools,
            reasoning=True,
            reasoning_steps=2,
            memory=True,
            verbose=True
        )

        doc_task = Task(
            description="Find the answer to: {question} using the available MCP tools.",
            expected_output="A very detailed and accurate answer to the user's PayPal question.",
            output_file="output/doc_answer.md",
            agent=doc_agent,
            markdown=True
        )

        crew = Crew(
            agents=[doc_agent],
            tasks=[doc_task],
            verbose=True,
        )

        result = crew.kickoff(inputs={"question": input("PayPal docs, how may I help you? ") })
        print("\nFinal Output:\n", result)
except RuntimeError as e:
    # Catch the specific RuntimeError raised by MCPServerAdapter
    print(f"Caught a RuntimeError during MCPServerAdapter initialization: {e}", file=sys.stderr)
    # The original exception is the cause of this RuntimeError, which is the KeyError
    original_exception = e.__cause__
    if original_exception:
        print(f"Original exception was: {type(original_exception).__name__}: {original_exception}", file=sys.stderr)
    print("Please check the MCP server's schema or try updating the libraries.", file=sys.stderr)
except Exception as e:
    # Catch any other unexpected exceptions
    print(f"An unexpected error occurred: {type(e).__name__}: {e}", file=sys.stderr)

Expected behavior

Should connect and list the tools

Screenshots/Code snippets

/usr/local/lib/python3.11/dist-packages/pydantic/fields.py:1076: PydanticDeprecatedSince20: Using extra keyword arguments on `Field` is deprecated and will be removed. Use `json_schema_extra` instead. (Extra keys: 'items', 'anyOf', 'enum', 'properties'). Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.11/migration/
  warn(
Caught a RuntimeError during MCPServerAdapter initialization: Failed to initialize MCP Adapter: '#/properties/subscriber/properties/name'
Original exception was: KeyError: '#/properties/subscriber/properties/name'
Please check the MCP server's schema or try updating the libraries.

Operating System

Ubuntu 20.04

Python Version

3.10

crewAI Version

0.46.0 (latest)

crewAI Tools Version

0.46.0

Virtual Environment

Venv

Evidence

/usr/local/lib/python3.11/dist-packages/pydantic/fields.py:1076: PydanticDeprecatedSince20: Using extra keyword arguments on `Field` is deprecated and will be removed. Use `json_schema_extra` instead. (Extra keys: 'items', 'anyOf', 'enum', 'properties'). Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.11/migration/
  warn(
Caught a RuntimeError during MCPServerAdapter initialization: Failed to initialize MCP Adapter: '#/properties/subscriber/properties/name'
Original exception was: KeyError: '#/properties/subscriber/properties/name'
Please check the MCP server's schema or try updating the libraries.

Possible Solution

Provide auth via headers and regular browser oauth

Additional context

NA

[eromoe]

+1 , for example: fastmcp client

from fastmcp.client import Client
from fastmcp.client.transports import (
    StreamableHttpTransport,
)

token = ''

transport = StreamableHttpTransport(
    url="http://localhost:6969/mcp",
    headers={"Authorization": f"Bearer {token}"}
)

async with Client(transport) as client:
    # Make calls to tools, JWT is automatically sent with every request
    
    resp = await client.call_tool(...)
    print(resp.content)

[saanvib]

+1, any resolution on this? Or workarounds to connect a CrewAI agent to a remote MCP server that requires authentication?

[amithkk]

Under the hood, this uses MCPAdapt, so adding auth to MCPAdapt will bring it to CrewAI as well. I have a PR in flight for authentication (OAuth, APIKey, Bearer) in general on the upstream repo grll/mcpadapt#70