Javascript library (<10kb) for the complex chromecast SDK

Castjs provides simple events and functions to communicate with chromecast devices from the browser.
This library works in chrome, opera, brave, firefox and vivaldi, see it in action and check out the online demo.



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Getting Started

Include the cast.min.js from cdnjs:

<script src="https://cdnjs.cloudflare.com/ajax/libs/castjs/5.3.0/cast.min.js"></script>

Casting Media

Casting a media source to your chromecast device. Make sure you enable CORS Header set Access-Control-Allow-Origin "*" on your media resources.

<button id="cast">Cast</button>

<script src="https://cdnjs.cloudflare.com/ajax/libs/castjs/5.3.0/cast.min.js"></script>
<script>
// Create new Castjs instance
const cjs = new Castjs();

// Wait for user interaction
document.getElementById('cast').addEventListener('click', function() {
    // Check if casting is available
    if (cjs.available) {
        // Initiate new cast session with a simple video
        cjs.cast('https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/Sintel.mp4');

        // A more complex example
        cjs.cast('https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/Sintel.mp4', {
            poster     : 'https://castjs.io/media/poster.jpg',
            title      : 'Sintel',
            description: 'Third Open Movie by Blender Foundation',
            subtitles: [{
                active: true,
                label : 'English',
                src   : 'https://castjs.io/media/english.vtt'
            }, {
                label : 'Spanish',
                src   : 'https://castjs.io/media/spanish.vtt'
            }],
        })
    }
});
</script>

Supported Browsers

Almost any Chromium based browser supports cast framework out of the box. Vivaldi Brave

API Documentation:

// Default instance
const cjs = new Castjs();

// Custom receiver or joinpolicy
const cjs = new Castjs({
    receiver  : 'CC1AD845',              // default
    joinpolicy: 'tab_and_origin_scoped', // default
//  joinpolicy: 'custom_controller_scoped',
//  joinpolicy: 'origin_scoped',
//  joinpolicy: 'page_scoped',
});

// Castjs Events
cjs.on('available',    ()  => {});  // Casting is available
cjs.on('connect',      ()  => {});  // Connected with device
cjs.on('disconnect',   ()  => {});  // Disconnected with device
cjs.on('statechange',  ()  => {});  // Device state
cjs.on('timeupdate',   ()  => {});  // Current time changed
cjs.on('volumechange', ()  => {});  // Volume changed
cjs.on('mute',         ()  => {});  // Muted state changed
cjs.on('unmute',       ()  => {});  // Muted state changed
cjs.on('playing',      ()  => {});  // Media is playing
cjs.on('pause',        ()  => {});  // Media is paused
cjs.on('end',          ()  => {});  // Media ended
cjs.on('buffering',    ()  => {});  // Media is buffering / seeking
cjs.on('event',        (e) => {});  // Catch all events except 'error'
cjs.on('error',        (e) => {});  // Catch any errors

// Castjs functions
cjs.cast(source, [metadata]); // Create session with media
cjs.volume(0.7);              // Change volume
cjs.play();                   // Play media
cjs.pause();                  // Pause media
cjs.mute();                   // Mutes media
cjs.unmute();                 // Unmutes media
cjs.subtitle(2);              // Change active subtitle index
cjs.seek(15);                 // Seek 15 seconds
cjs.seek(15.9, true);         // Seek 15.9% percentage
cjs.disconnect();             // Disconnect session

// Castjs properties
cjs.version          // Castjs Version
cjs.receiver         // Receiver ID
cjs.available        // Casting is available
cjs.connected        // Connected with cast device
cjs.device           // Cast device name
cjs.src              // Media source
cjs.title            // Media title
cjs.description      // Media description
cjs.poster           // Media poster image
cjs.subtitles        // Media subtitles
cjs.volumeLevel      // Volume level
cjs.muted            // If muted
cjs.paused           // If paused
cjs.time             // Time in seconds
cjs.timePretty       // Time formatted in time hh:mm:ss
cjs.duration         // Duration in seconds
cjs.durationPretty   // Duration formatted in hh:mm:ss
cjs.progress         // Progress in percentage 0 - 100
cjs.state            // State of cast device

FAQ

Question: Can I cast local resources?
Answer: It was possible in the past from the browser by using service workers. But we had to remove it from our library because Google dropped support, see https://github.com/fenny/chromecast-service-worker-crash

Question: Do I need to enable CORS for all hosts?
Answer: Yes and no. Chromecast is using an User-Agent that contains the word CrKey -> Mozilla/5.0 (X11; Linux armv7l) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.225 Safari/537.36 CrKey/1.56.500000 DeviceType/Chromecast so you could allow agents containing CrKey or Chromecast but this is not officialy documented.

TODO

- Add local media and stream support after google fixes service worker crash
- Add name space messaging support for custom receivers
- Maybe add video element support: new Castjs($('#video'))

// Suggestions? Let me know!

Do you want to support my work, feel free to donate a ☕ Hot Beverage