Cloud MCP Server Connection Test Tool

This is a cloud MCP Server that uses only Streamable HTTP. The public endpoint is:

https://你的域名/mcp

The upstream can discover and call mcp_connection_test, which after being called always returns MCP连接成功. The tool does not call a model and does not require an API Key.

Deployment Structure

上游 MCP 客户端 -> HTTPS 443 -> Caddy -> MCP Server 8000

Caddy automatically applies for and renews HTTPS certificates, and the MCP Server's port 8000 is not directly exposed to the public.

Related MCP server: MCP MCPO Demo Server

1. Prepare the Server and Domain

1. Install Docker Engine and the Docker Compose plugin on the cloud server.

2. Prepare a domain, e.g. mcp.example.com.

3. Add an A record for the domain, pointing to the cloud server's public IP.

4. Allow TCP 80 and 443 in the cloud provider's security group and the server firewall.

For MCP_DOMAIN, fill in only the domain; do not include https:// or a path.

2. Upload the Project

Execute on a local Mac, replacing SERVER_USER and SERVER_IP with real values. This explicitly excludes the local .env and virtual environment, so that old API Keys or unrelated files are not uploaded to the server:

rsync -av \
  --exclude='.env' \
  --exclude='.venv' \
  --exclude='__pycache__' \
  "/Users/clarence/Desktop/项目/兴先达/MCP测试/" \
  SERVER_USER@SERVER_IP:~/mcp-connection-test/

Log in to the server:

ssh SERVER_USER@SERVER_IP
cd ~/mcp-connection-test

3. Fill in the Domain and Start

cp deploy.env.example deploy.env

Edit deploy.env:

MCP_DOMAIN=mcp.example.com

Build and start in the background:

docker compose --env-file deploy.env up -d --build

View the running status and logs:

docker compose --env-file deploy.env ps
docker compose --env-file deploy.env logs --tail=100

After the certificate has been issued, the MCP address is:

https://mcp.example.com/mcp

4. Verify Tool Discovery and Invocation

Execute on a local Mac to verify the public network link:

/opt/homebrew/Caskroom/miniconda/base/bin/python \
  "/Users/clarence/Desktop/项目/兴先达/MCP测试/verify_remote.py" \
  https://mcp.example.com/mcp

On success, it will show:

发现工具：mcp_connection_test
调用返回：MCP连接成功

This step actually executes MCP initialization, tools/list, and tools/call, which is more accurate than ordinary port or HTTP checks.

5. Upstream Configuration

Configure the upstream MCP client's server URL as:

https://mcp.example.com/mcp

Tool name:

mcp_connection_test

The invocation parameters can be an empty object:

{}

You can also pass probing content:

{
  "probe": "upstream-health-check"
}

Updating and Stopping

After updating the code, redeploy:

docker compose --env-file deploy.env up -d --build

Stop the service:

docker compose --env-file deploy.env down

FAQ

• Returns 421 Invalid Host header: The domain in deploy.env does not match the domain you are accessing.

• HTTPS certificate not issued: Check the domain's A record and the security group's ports 80 and 443.

• View MCP service logs: docker compose --env-file deploy.env logs mcp-server.

• View HTTPS proxy logs: docker compose --env-file deploy.env logs caddy.

The current service has no authentication, because it only has a side-effect-free connection test tool. If real business tools are added later, you should add MCP authentication, or in the cloud security group only allow the upstream's fixed IP to access.