TwiML™ Voice: <Enqueue>

The <Enqueue> verb supports the following attributes that modify its behavior:

The action attribute takes an absolute or relative URL as a value. A request is made to this URL when the call leaves the queue, describing the dequeue reason and details about the time spent in the queue, which are described below. In the case where a call is dequeued due to a REST API request or the <Leave> verb, the action URL is requested right away. In the case where a call is dequeued via the <Dial> verb, the action URL is hit once when the bridged parties disconnect. If no action is provided, Twilio will fall through to the next verb in the document, if any.

Twilio passes the following parameters in addition to the standard TwiML Voice request parameters with its request to the action URL:

The following values represent the result of an attempt to enqueue a caller.

The method attribute specifies the HTTP method Twilio uses when sending a request to the action URL. takes the value GET or POST. POST is the default value.

The waitUrl attribute specifies the URL to play for callers waiting in the queue. The URL may return an MP3 file, a WAV file, or a TwiML document.

Once the TwiML document located at the waitUrl runs out of verbs to execute, Twilio re-requests the waitUrl. This loops the hold music indefinitely. The <Redirect> verb can be used for multiple TwiML document call flows, but a call will always return to the waitUrl once there is no TwiML left to execute.

The following verbs are supported in the TwiML document located at the waitUrl:

Twilio will pass the following parameters in addition to the standard TwiML Voice request parameters with its request to the 'waitUrl' URL:

If no waitUrl is specified, Twilio will use its own default classical playlist which contains a selection of nice Creative Commons classical music.

Here's a list of S3 buckets we've assembled with other genres of music for you to choose from:

If you don't wish anything to be played while the caller is waiting in the queue, set waitUrl to an empty string ('').

This attribute indicates which HTTP method to use when requesting waitUrl. It defaults to POST if you specify a waitUrl. If you have not specified a waitUrl, Twilio will make a GET request to the default classical playlist. Be sure to use GET if you are directly requesting static audio files such as WAV or MP3 files so that Twilio properly caches the files.

The workflowSid attribute tells Twilio to create a new TaskRouter Task to represent this call and specifies the ID of the desired Workflow to handle it.

If workflowSid is specified, it is not necessary to specify a name for the Queue to place the call in. When a Worker is identified to handle the call it can be dequeued and connected using the dequeue assignment instruction.

The "noun" of a TwiML verb is the nested content of the verb that's not a verb itself; it's the information the verb acts upon. These are the nouns for <Enqueue>:

You can find more information and examples on how to use <Task> on the TaskRouter TwiML Integration page.

This TwiML document tells Twilio to fetch the wait-music.xml TwiML document and execute it while the caller is in the queue:

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const VoiceResponse = require('twilio').twiml.VoiceResponse;
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const response = new VoiceResponse();
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response.enqueue({
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    waitUrl: 'wait-music.xml'
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}, 'support');
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console.log(response.toString());

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<?xml version="1.0" encoding="UTF-8"?>
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<Response>
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    <Enqueue waitUrl="wait-music.xml">support</Enqueue>
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</Response>

The wait-music.xml TwiML document plays some nice hold music:

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const VoiceResponse = require('twilio').twiml.VoiceResponse;
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const response = new VoiceResponse();
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response.play('http://com.twilio.sounds.music.s3.amazonaws.com/MARKOVICHAMP-Borghestral.mp3');
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console.log(response.toString());

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<?xml version="1.0" encoding="UTF-8"?>
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<Response>
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    <Play>http://com.twilio.sounds.music.s3.amazonaws.com/MARKOVICHAMP-Borghestral.mp3</Play>
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</Response>

• You can use the parameters on the waitUrl request to <Say> back to the caller what their queue position is and how long they can expect to wait.