[MCP server issue] Cannot access MCP server with env

[Yuanqi-babe]

What happened?

Describe the bug
I installed a Stdio MCP server following the configuration:
"github.com/mendableai/firecrawl-mcp-server": {
"command": "npx",
"args": ["-y", "firecrawl-mcp"],
"env": {
"FIRECRAWL_API_KEY": "fc-294547563d9344ef8409bbb8e80f5307"
},
"disabled": false,
"autoApprove": []
}
}

However, when I ran it in AutoGEN 0.4, it throws an unexpected error when registering MCP tools:

        logger.info("Setting up fetch MCP server...")
        fetch_mcp_server = StdioServerParams(command="env", args=["FIRECRAWL_API_KEY=fc-294547563d9344ef8409bbb8e80f5307", "npx", "-y" ,"firecrawl-mcp"])
        fetch_tools = await mcp_server_tools(fetch_mcp_server)
        logger.info(f"Fetch tools loaded: {len(fetch_tools)} tools")

Printed on the console it shows the successful onboard of this tool but:

FireCrawl MCP Server running on stdio
/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/pydantic/_internal/_fields.py:192: UserWarning: Field name "schema" in "DynamicModel" shadows an attribute in parent "BaseModel"
  warnings.warn(
2025-03-20 09:15:17,824 - ERROR
An error occurred: Each oneOf variant must have a type const
Traceback (most recent call last):
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/test_mcp.py", line 99, in main
    fetch_tools = await mcp_server_tools(fetch_mcp_server)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_factory.py", line 139, in mcp_server_tools
    return [StdioMcpToolAdapter(server_params=server_params, tool=tool) for tool in tools.tools]
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_stdio.py", line 48, in __init__
    super().__init__(server_params=server_params, tool=tool)
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_base.py", line 36, in __init__
    input_model = create_model(tool.inputSchema)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/__init__.py", line 42, in create_model
    return builder.create_pydantic_model(schema, root_schema)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/model_builder.py", line 62, in create_pydantic_model
    field_type = self._get_field_type(field_schema, root_schema)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/model_builder.py", line 92, in _get_field_type
    return self.combiner_handler.handle_one_of(field_schema, root_schema)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/handlers.py", line 135, in handle_one_of
    raise CombinerError("Each oneOf variant must have a type const")
json_schema_to_pydantic.exceptions.CombinerError: Each oneOf variant must have a type const
Traceback (most recent call last):
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/test_mcp.py", line 173, in <module>
    asyncio.run(main())
  File "/usr/lib64/python3.12/asyncio/runners.py", line 194, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.12/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.12/asyncio/base_events.py", line 687, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/test_mcp.py", line 99, in main
    fetch_tools = await mcp_server_tools(fetch_mcp_server)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_factory.py", line 139, in mcp_server_tools
    return [StdioMcpToolAdapter(server_params=server_params, tool=tool) for tool in tools.tools]
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_stdio.py", line 48, in __init__
    super().__init__(server_params=server_params, tool=tool)
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_base.py", line 36, in __init__
    input_model = create_model(tool.inputSchema)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/__init__.py", line 42, in create_model
    return builder.create_pydantic_model(schema, root_schema)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/model_builder.py", line 62, in create_pydantic_model
    field_type = self._get_field_type(field_schema, root_schema)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/model_builder.py", line 92, in _get_field_type
    return self.combiner_handler.handle_one_of(field_schema, root_schema)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/json_schema_to_pydantic/handlers.py", line 135, in handle_one_of
    raise CombinerError("Each oneOf variant must have a type const")
json_schema_to_pydantic.exceptions.CombinerError: Each oneOf variant must have a type const

To Reproduce

Which packages was the bug in?

Python Extensions (autogen-ext)

AutoGen library version.

Python dev (main branch)

Other library version.

-mcp

Model used

No response

Model provider

None

Other model provider

No response

Python version

3.12

.NET version

None

Operating system

CentOS

[ekzhu]

Could you print out your tool schema without using AutoGen from an mcp client? Looks like the tool schema cannot be used to create a json schema using pydantic:

  File "/home/ec2-user/bedrock-access-gw/bedrock-access-gateway/test-script/venv/lib64/python3.12/site-packages/autogen_ext/tools/mcp/_base.py", line 36, in __init__
    input_model = create_model(tool.inputSchema)