This is a small "hack" that I built on a Twitch stream that uses thibauts/node-castv2-client to communicate with the Chromecast and the Spotify Web API to search for songs and extract the Preview Snippets to play them with the DefaultMediaReceiver on the Chromecast.
git clone https://github.com/dkundel/spotify-chromecast-api.git
cd spotify-chromecast-api
npm install
node .This will install all dependencies and start the server listening by default on Port 3000.
Right now due to a bug it will only connect to one Chromecast since there was a bug during my stream that would double connect.
List all endpoints
List all devices available
Gets the first Chromecast
Reads a status body parameter that is x-www-form-urlencoded and can be Play, Pause or Skip and controls the music flow.
Gets a song body parameter that is x-www-form-urlencoded and it will look up the first song that is returned from Spotify and add the preview mp3 file to the playlist or plays it if the playlist is empty.
Dominik Kundel