The httpx.ConnectError usually indicates a network connectivity issue rather than authentication. Since you enabled private connectivity, your MCP server is likely only accessible within the VPC or through a configured private endpoint. From a local notebook or environment outside that network, the connection will fail. To fix this, either:

• Use a notebook or compute instance within the same VPC or subnet.
• Configure a secure VPN or bastion host to access the private endpoint.
• If public access is acceptable, adjust the MCP deployment to allow public connectivity temporarily for testing.
  Check the MCP docs on private connectivity and endpoints — the error is consistent with trying to reach a private-only service from outside its network.”

I can also draft a simpler, one-paragraph version for quick forum posting if you want.

will try and come back if solved, thanks @Thompson2345 !

Check your network settings and firewall rules — the error means your environment can’t reach the MCP server. Make sure the server’s endpoint is accessible from your workspace and that private connectivity or VPC settings allow outbound traffic to it.

I wasn't setting the MCP server as a streamable http, I've done that already and it works!