how does one interact with MCP servers without mcp-libraries?

im building som dum lil foss llm thingy for godot and now im interested in letting users implement their own MCP servers.

so like - okay, the model context protocol page says, that most servers use stdio for every interaction. So now - the request format can be seen here, its apparently a JSONrpc thing.

so - first thing i want to do is retrieving all the capabilities the server has.

i looked through all the tabs in the latest docs, but could not find the command for listing all the capabilities. so i installed some filesystem mcp server which runs well and tried this:

 bash

    
PS C:\Users\praktikant> npx -y @modelcontextprotocol/server-filesystem "C:\Users\praktikant\Desktop"
Secure MCP Filesystem Server running on stdio
Allowed directories: [ 'C:\\Users\\praktikant\\Desktop' ]
{\
"jsonrpc": "2.0",\
"id": 1,\
"method": "capabilities",\
"params": {}\
}


  

aaaaaand nothing was returned. no string, no nothing.

so maybe its not a string which is sent via stdio but some other byte-based thing?

if anyone has experience with this, or is gud at guessing, pls tell me what u think i might be missing here <3