Or do I need to build this on top of libp2p with a queue for example?
My js-libp2p version is 0.26.1 (but I would upgrade to 0.29.0)
There’s no exposed API for this yet, however we are looking at adding Connection Gaters to js-libp2p 0.30 (Go recently added support for this). This would provide the ability to proactively prohibit/allow connections.
What are you trying to do?