MCP server is not getting connected for the below snippet:

python
from anthropic import Anthropic

# Initialize Anthropic client
client = Anthropic(api_key="")

# Use the MCP server URL you generated
mcp_server_url = ""

# Use MCP with Anthropic (beta feature)
response = client.beta.messages.create(
model="claude-sonnet-4-5",
system="You are a helpful assistant with access to various tools through MCP. Use these tools to help the user. Do not ask for confirmation before using the tools.",
max_tokens=1000,
messages=[{
    "role": "user",
    "content": "What all repos do I have in github and channels in slack?"
}],
mcp_servers=[{
    "type": "url",
    "url": mcp_server_url,
    "name": "testing-init-flow"
}],
betas=["mcp-client-2025-04-04"]  # Enable MCP beta
)

print(response.content)

Error:

BadRequestError: Error code: 400 - {'type': 'error', 'error': {'type': 'invalid_request_error', 'message': 'Connection error while communicating with MCP server: Connection closed by server'}, 'request_id': 'req_xx'}

I have been following the doc: https://docs.composio.dev/docs/mcp-quickstart. Any guidance will be helpful, thanks in Advance!

Could you share the exact error message you're seeing? Also, I would not suggest sharing MCP server URL + user/connection ID on a public medium.

Sure have removed the MCP server url and have pasted the error above

Thanks, it could be happening with this MCP client.. can you share the request ID from logs? and maybe can you try this in a different MCP client like MCP inspector / postman and see if issue persist? Meanwhile I'll see if I can repro the same in anthropic.

Hey thanks a lot but it got fixed. Maybe issue was that I created MCP server without any tools and the anthropic client didn’t even connect to it instead of showing that no tools are available