So this is very very basic hobby radio setup with WS and SSE (via Centrifugo) for folks who're trying out liquidsoap and icecast and want to have nowplaying info on their websites or to try at local home environment. All you need is Docker.

It illustrates:

• How Liquidsoap can send nowplaying info to your website or homepage using Server Sent Events or Websocket.
• It urges you to stop fetching our tired status-json.xsl :) Because you may want to stop using Icecast at all and look into HLS.
• Liquidsoap doesn't send data directly to Centrifugo (although it can) because it's more fancy to have an API where data is collected and sent further enabling "on_track_change" notifications and tunable intervals.

What we have inside:

• Liquidsoap v2.3.0 - https://github.com/savonet/liquidsoap (dockerfile with entrypoint script from @vitoyucepi)
• Icecast KH icecast-2.4.0-kh22 - https://github.com/karlheyes/icecast-kh
• Centrifugo latest - https://github.com/centrifugal/centrifugo
• Node.js API

To setup

• Download the repo
• Change - /path/to/music:/home/radio/music in the docker-compose.yaml file. /path/to/music -> /your/real/path/to/music
• RUN: docker compose up -d or docker compose up (to see wtf is happening 😄)
• It's nice to run under 1000 user acoount.

Of course you can edit and tune everything inside docker folder and scale it to be a real radio station on the internet.

---

After installation you'll have following endpoints:

• http://localhost:8000/stream - your Icecast stream with music
• http://localhost:8007/skipQueue?queueType=default - skips default queue
• http://localhost:8007/skipQueue - skips interrupting queue
• http://localhost:8007/queuePlaylist?track_sensitive=true&playlist_name=/path/to/playlist - queues playlist to default queue
• http://localhost:8007/queuePlaylist?playlist_name=/path/to/playlist - queues playlist to interrupting queue
• http://localhost:8007/queueFile?track_sensitive=true&file=/path/to/file - queues file to default queue
• http://localhost:8007/queueFile?file=/path/to/file - queues file to interrupting queue
• http://localhost:8007/metadata - all metadata endpoint
• http://localhost:8007/skip - skip endpoint
• http://localhost:8007/cover - coverart endpoint will show you current coverart if your file is tagged with it
• http://localhost:8007/nowplaying - nowplaying info endpoint

Will give us a json with nowplaying and song history (10 tracks):

{"station":
{"name":"Radio","shortcode":"radio","timezone":"Europe/London"},
"now_playing":
{"played_at":1735060884.4,
"played_at_timestamp_old":"1735060884.39",
"played_at_date_time_old":"2024/12/24 17:21:24",
"duration":250.494943311,
"elapsed":57.38,
"remaining":193.114943311,
"playlist":"",
"filename":"/home/radio/music/Various Artists - BIRP! Best of 2020/041 - Kowloon - Come Over.mp3",
"song":
{"text":"Kowloon - Come Over",
"artist":"Kowloon",
"title":"Come Over",
"album":"Come Over - Single",
"genre":"Alternative"}},
"song_history":
[{"played_at":1735060884.4,"played_at_timestamp_old":"1735060884.39","played_at_timestamp":1735060884.4,"played_at_date_time_old":"2024/12/24 17:21:24","played_at_date_time":"2024/12/24 17:21:24","playlist":"","filename":"/home/radio/music/Various Artists - BIRP! Best of 2020/041 - Kowloon - Come Over.mp3","song":{"text":"Kowloon - Come Over","artist":"Kowloon","title":"Come Over","album":"Come Over - Single","genre":"Alternative"}}]}

Don't fetch it :) cause we got SSE and WS :) :

Endpoint to get SSE (WS) events

• ws://localhost:9998/connection/ws
• http://localhost:9998/connection/sse

To get our station data we connect to:

• http://localhost:9998/connection/sse?cf_connect={%22subs%22:{%22station:radio%22:{%22recover%22:true}}}

Basic js implementations (Just like AzuraCast ones):

const sseBaseUri = "http://localhost:9998/connection/sse";
const sseUriParams = new URLSearchParams({
  "cf_connect": JSON.stringify({
    "subs": {
      "station:radio": {"recover": true}
    }
  })
});
const sseUri = sseBaseUri+"?"+sseUriParams.toString();
const sse = new EventSource(sseUri);

let nowplaying = {};
let currentTime = 0;

// This is a now-playing event from a station. Update your now-playing data accordingly.
function handleSseData(ssePayload, useTime = true) {
  const jsonData = ssePayload.data;

  if (useTime && 'current_time' in jsonData) {
    currentTime = jsonData.current_time;
  }

  nowplaying = jsonData.np;
}

sse.onmessage = (e) => {
  const jsonData = JSON.parse(e.data);

  if ('connect' in jsonData) {
    const connectData = jsonData.connect;

    if ('data' in connectData) {
      // Legacy SSE data
      connectData.data.forEach(
        (initialRow) => handleSseData(initialRow)
      );
    } else {
      // New Centrifugo time format
      if ('time' in connectData) {
        currentTime = Math.floor(connectData.time / 1000);
      }

      // New Centrifugo cached NowPlaying initial push.
      for (const subName in connectData.subs) {
        const sub = connectData.subs[subName];
        if ('publications' in sub && sub.publications.length > 0) {
          sub.publications.forEach((initialRow) => handleSseData(initialRow, false));
        }
      }
    }
  } else if ('pub' in jsonData) {
    handleSseData(jsonData.pub);
  }
};

WS:

let socket = new WebSocket("ws://localhost:9998/connection/ws);

socket.onopen = function(e) {
  socket.send(JSON.stringify({
    "subs": {
      "station:radio": {"recover": true}
    }
  });
};

let nowplaying = {};
let currentTime = 0;

// Handle a now-playing event from a station. Update your now-playing data accordingly.
function handleSseData(ssePayload, useTime = true) {
  const jsonData = ssePayload.data;

  if (useTime && 'current_time' in jsonData) {
    currentTime = jsonData.current_time;
  }

  nowplaying = jsonData.np;
}

socket.onmessage = function(e) {
  const jsonData = JSON.parse(e.data);

  if ('connect' in jsonData) {
    const connectData = jsonData.connect;

    if ('data' in connectData) {
      // Legacy SSE data
      connectData.data.forEach(
        (initialRow) => handleSseData(initialRow)
      );
    } else {
      // New Centrifugo time format
      if ('time' in connectData) {
        currentTime = Math.floor(connectData.time / 1000);
      }

      // New Centrifugo cached NowPlaying initial push.
      for (const subName in connectData.subs) {
        const sub = connectData.subs[subName];
        if ('publications' in sub && sub.publications.length > 0) {
          sub.publications.forEach((initialRow) => handleSseData(initialRow, false));
        }
      }
    }
  } else if ('pub' in jsonData) {
    handleSseData(jsonData.pub);
  }
};

Example of incoming data:

data: {"connect":
{"client":"4fe1-9386-2ef1ede3f0fa","version":"5.4.9",
"subs":{"station:radio":
{"recoverable":true,"epoch":"kCIB",
"publications":
[{"data":{"np":{"station":
{"name":"Station","shortcode":"radio","timezone":"Europe/London"},
"now_playing":
{"played_at":1735060884.4,"played_at_timestamp_old":"1735060884.39","played_at_timestamp":1735060884.4,"played_at_date_time_old":"2024/12/24 17:21:24","played_at_date_time":"2024/12/24 17:21:24","duration":250.494943311,"elapsed":12.66,"remaining":237.834943311,"playlist":"","filename":"/home/radio/music/Various Artists - BIRP! Best of 2020/041 - Kowloon - Come Over.mp3","song":{"text":"Kowloon - Come Over","artist":"Kowloon","title":"Come Over","album":"Come Over - Single","genre":"Alternative"}},
"song_history":
[{"played_at":1735060884.4,"played_at_timestamp_old":"1735060884.39","played_at_timestamp":1735060884.4,"played_at_date_time_old":"2024/12/24 17:21:24","played_at_date_time":"2024/12/24 17:21:24","playlist":"","filename":"/home/radio/music/Various Artists - BIRP! Best of 2020/041 - Kowloon - Come Over.mp3","song":{"text":"Kowloon - Come Over","artist":"Kowloon","title":"Come Over","album":"Come Over - Single","genre":"Alternative"}}]}},"offset":3}],"recovered":true,"positioned":true,"was_recovering":true}},"ping":25,"session":"043b7d46-ab47","time":1735060899380}}

---

Of course it's all highly customizable. And even icecast server info can be fetched from inside of Liquidsoap and then added to nowplaying:

...

icecast_source_name = ref("")
icecast_source_listeners = ref("")
icecast_source_start = ref("")
icecast_server_start = ref("")
icecast_source_description = ref("")

def icecast_stats()
  api_url = "http://localhost:8000/status-json.xsl?mount=/stream"  
  http_response = http.get(api_url)

  if http_response.status_code != 200 then
      log.important("Request to #{string.quote(api_url)} failed with status \
                     #{http_response.status_code}. Status message: \
                     #{string.quote(http_response.status_message)}.")
      null()
  else
    try
     let json.parse ({
        icestats
      } : {
        icestats: {
	  server_start: string,
          source: {
            genre: string,
            listener_peak: int,
            listeners: int,
            listenurl: string,
            server_description: string,
            server_name: string,
            server_type: string,
            stream_start: string,
          }
        }
      }) = http_response
      icecast_source_name := icestats.source.server_name
      icecast_source_listeners := string(icestats.source.listeners)
      icecast_source_start := icestats.source.stream_start
      icecast_server_start := icestats.server_start
      icecast_source_description := icestats.server_description
    catch _ do
      log.important("Unable to parse api response.")
      null()
    end

  end

  print("icecast_source_name: #{icecast_source_name()}")
  print("icecast_source_listeners: #{icecast_source_listeners()}")
  print("icecast_source_start: #{icecast_source_start()}")
  print("icecast_server_start: #{icecast_server_start()}")

end
thread.run(icecast_stats, every=60.)

...

With the use of some frontend/webpage it could look like this: