librespot-golang is an opensource Golang library based on the librespot project, allowing you to control Spotify Connect devices, get metadata, and play music. It has itself been based on SpotControl, and its main goal is to provide a suitable replacement for the defunct libspotify.
This is still highly experimental and in development. Do not use it in production projects yet, as the API is incomplete and subject to heavy changes.
This package can be installed using:
go get github.com/RoflCopter24/librespot-golang
To use the package look at the example micro-controller (for Spotify Connect), or micro-client (for audio playback).