Is there a way to connect/subscribe to Postgres logical replication/streaming replication using node or go? I know its a TCP/IP connection but not exactly where to start. I also know there is a package for this, was wondering for more of a vanilla/understanding solution.
I'm not certain what you want, but maybe you are looking for “logical decoding”.
If you want to directly speak the replication protocol with the server, you'll have to implement it in your code, but that information is pretty useless, as it only contains the physical changes to the data files.
If you want logical decoding, there is the test_decoding module provided by PostgreSQL, and here are some examples how it can be used.
Mind that test_decoding is for testing. For real-world use cases, you will want to use a logical decoding plugin that fits your needs, for example wal2json.
If that's what you want to consume, you'll have to look up the documentation for the logical decoding plugin you want to use to learn the format in which it provides the information.