What's a good library that implements the Bitcoin protocol that would allow me to make an incomplete node that connects to other nodes and just receives the new transactions?

I know there are half-node implementations out there but they are either not working or they are outdated with the current state of the protocol. Python, C/C++, Go... any language would work.

I'm not talking about the JSON-RPC API. I'm talking about the protocol that Bitcoin nodes use to talk to each other.