TwiML™ Voice: <Record>
The <Record> verb records the caller’s voice and returns to you the URL of a file containing the audio recording. You can optionally generate text transcriptions of recorded calls by setting the transcribe attribute of the <Record> verb to true.
Legal implications of call recording
If you choose to record voice or video calls, you need to comply with certain laws and regulations, including those regarding obtaining consent to record (such as California’s Invasion of Privacy Act and similar laws in other jurisdictions). Additional information on the legal implications of call recording can be found here.
Notice: Twilio recommends that you consult with your legal counsel to make sure that you are complying with all applicable laws in connection with communications you record or store using Twilio.
Verb Attributes
The <Record> verb supports the following attributes that modify its behavior:
| Attribute Name | Allowed Values | Default Value |
|---|---|---|
| action | Relative or absolute URL | current document URL |
| method | GET, POST |
POST |
| timeout | Positive integer | 5 |
| finishOnKey | Any digit, #, * |
1234567890*# |
| maxLength | Integer greater than 1 | 3600 (1 hour) |
| playBeep | true, false |
true |
| trim | trim-silence, do-not-trim |
trim-silence |
| recordingStatusCallback | relative or absolute URL | None |
| recordingStatusCallbackMethod | GET, POST |
POST |
| recordingStatusCallbackEvent | in-progress, completed, absent |
completed |
| transcribe | true, false |
false |
| transcribeCallback | Relative or absolute URL | None |
Use one or more of these attributes in a <Record> verb like so:
action
The action attribute takes a relative or absolute URL as a value. When recording is finished, Twilio will make a GET or POST request to this URL including the parameters below. If no action is provided, <Record> will request the current document’s URL.
After making this request, Twilio will continue the current call using the TwiML received in your response. Keep in mind that by default Twilio will re-request the current document’s URL. This can lead to unwanted looping behavior if you’re not careful. Any TwiML verbs occurring after a <Record> are unreachable.
By default, silent recordings are saved by Twilio. If you do not need to retain silent recordings, reach out to Twilio Support.
When modifying a live call to redirect to a <Record> verb an action URL must be provided. Failure to provide an action URL will result in an 11100 error.
If you started or updated a call with a twiml parameter, the action URLs for <Record>, <Gather>, and <Pay> must be absolute.
The Call Resource API Docs have language-specific examples of creating and updating Calls with TwiML:
- See "Create a Call resource with TwiML" under Create a Call Resource to see examples of creating a call with a
twimlparameter. - See "Update a Call resource with TwiML" under Update a Call Resource to see examples of updating a call with a
twimlparameter.
Request Parameters
Twilio will pass the following parameters in addition to the standard TwiML Voice request parameters with
its request to the action URL:
| Parameter | Description |
|---|---|
| RecordingUrl | The URL of the recorded audio. The recording file may not yet be accessible when the action callback is sent. Use recordingStatusCallback for reliable notification on when the recording is available for access. |
| RecordingDuration | The duration of the recorded audio (in seconds). To get a final accurate recording duration after any trimming of silence, use recordingStatusCallback. |
| Digits | The key (if any) pressed to end the recording, or hangup if the caller hung up. |
A request to the RecordingUrl will return a recording in binary WAV audio format by default. To request the recording in MP3 format, append ".mp3" to the RecordingUrl value.
method
The method attribute takes the value GET or POST. This tells Twilio whether to request the action URL via HTTP GET or POST. This attribute is modeled after the HTML form method attribute. POST is the default value.
timeout
The timeout attribute tells Twilio to end the recording after a number of seconds of silence has passed. To disable this feature, set timeout to 0. The default is 5 seconds.
finishOnKey
The finishOnKey attribute lets you choose a set of digits that, when entered, end the recording. For example, if you set finishOnKey to # and the caller presses the # key, Twilio will immediately stop recording and submit RecordingUrl, RecordingDuration, and # as parameters in a request to the action URL. The allowed values are the digits 0-9, # and *. The default is 1234567890*# — ie. any key will end the recording. Unlike <Gather>, you may specify more than one character as a finishOnKey value.
In some instances, when using the finishOnKey attribute, the last part of the audio (approximately the one second before the key is pressed) may not be recorded.
maxLength
The maxLength attribute lets you set the maximum length for the recording in seconds. If you set maxLength to 30, the recording will automatically end after 30 seconds of recorded time has elapsed. The defaults are 3600 seconds (one hour) for a normal recording, and 120 seconds (two minutes) for a transcribed recording. Twilio Client calls using <Record> are limited to 600 seconds (ten minutes).
playBeep
The playBeep attribute allows you to toggle between playing a sound before the start of a recording. If you set the value to false, no beep sound will be played.
trim
The trim attribute lets you specify whether to trim leading and trailing silence from your audio files. The default is trim-silence, which removes any silence at the beginning and end of your recording. This may cause the duration of the recording to be slightly less than the duration of the call.
recordingStatusCallback
The recordingStatusCallback attribute takes a relative or absolute URL as an argument. If a recordingStatusCallback URL is given, Twilio will make a GET or POST request to the specified URL when the recording is available to access.
Request Parameters
Twilio will pass the following parameters with its request to the recordingStatusCallback URL:
| Parameter | Description |
|---|---|
| AccountSid | The unique identifier of the Account responsible for this recording. |
| CallSid | A unique identifier for the call associated with the recording. |
| RecordingSid | The unique identifier for the recording. |
| RecordingUrl | The URL of the recorded audio. |
| RecordingStatus | The status of the recording. Possible values are: completed, failed. |
| RecordingDuration | The length of the recording, in seconds. |
| RecordingChannels | The number of channels in the final recording file as an integer. Only one channel is supported for the <Record> verb. |
| RecordingSource | The initiation method used to create this recording. RecordVerb is returned for recordings initiated via the <Record> verb. |
recordingStatusCallbackMethod
This attribute indicates which HTTP method to use when requesting recordingStatusCallback. It defaults to POST.
recordingStatusCallbackEvent
The recordingStatusCallbackEvent allows you to specify which recording status changes should generate a webhook to the URL specified in the recordingStatusCallback attribute. The available values are:
in-progress: the recording has started.completed: the recording is complete and available.absent: the recording is absent and inaccessible.
To specify more than one value, separate each with a space. The default value is completed.
transcribe
The transcribe attribute tells Twilio that you would like a text representation of the audio of the recording. Twilio will pass this recording to our speech-to-text engine and attempt to convert the audio to human readable text. The transcribe option is not enabled by default. If you do not wish to perform transcription, simply do not include the transcribe attribute.
Notes
- Transcription is a paid feature. If you include a
transcribeortranscribeCallbackattribute on yourRecordverb, your account will be charged. See the pricing page for our transcription prices. - Transcription is only supported in American English.
Additionally, transcription is currently limited to recordings initiated via the TwiML <Record> verb with a duration greater than two seconds and less than 120 seconds. If you request a transcription for a recording outside these duration limits, Twilio will write a warning to your debug log rather than transcribe the recording.
transcribeCallback
The transcribeCallback attribute is used in conjunction with the transcribe attribute. It allows you to specify a URL to which Twilio will make an asynchronous POST request when the transcription is complete. This is not a request for TwiML and the response will not change call flow, but the request will contain the standard TwiML request parameters as well as transcription specific ones.
If transcribeCallback is specified, then there is no need to specify transcribe=true; it is implied. If you specify transcribe=true without a transcribeCallback, the completed transcription will be stored for you to retrieve later (see the REST API Transcriptions section), but Twilio will not asynchronously notify your application.
Twilio will not make a request to the provided transcribeCallback URL if the voice recording is missing or absent.
The transcribeCallback URL attribute is considered Not PII.
Request Parameters
Twilio will pass the following parameters with its request to the transcribeCallback URL:
| Parameter | Description |
|---|---|
| TranscriptionSid | The unique 34-character ID of the transcription. |
| TranscriptionText | The text of the transcription. |
| TranscriptionStatus | The status of the transcription attempt: either completed or failed. |
| TranscriptionUrl | The URL for the transcription’s REST API resource. |
| RecordingSid | The unique 34-character ID of the recording from which the transcription was generated. |
| RecordingUrl | The URL for the transcription’s source recording resource. |
| CallSid | A unique identifier for this call, generated by Twilio. |
| AccountSid | Your Twilio account ID. It is 34 characters long, and always starts with the letters AC. |
| From | The phone number or client identifier of the party that initiated the call. Phone numbers are formatted with a + and country code, eg. +16175551212 ([E.164][e164] format). Client identifiers begin with the client: URI scheme; for example, for a call from a client named tommy, the From parameter will be client:tommy. |
| To | The phone number or client identifier of the called party. Phone numbers are formatted with a + and country code, eg. +16175551212 ([E.164][e164] format). Client identifiers begin with the client: URI scheme; for example, for a call to a client named joey, the To parameter will be client:joey. |
| CallStatus | A descriptive status for the call. The value is one of queued, ringing, in-progress, completed, busy, failed, or no-answer. See the CallStatus section for more details. |
| ApiVersion | The version of the Twilio API used to handle this call. For incoming calls, this is determined by the API version set on the called number. For outgoing calls, this is the API version used by the outgoing call’s REST API request. |
| Direction | A string describing the direction of the call: inbound for inbound calls, outbound-api for calls initiated via the REST API, or outbound-dial for calls initiated by a <Dial> verb. |
| ForwardedFrom | This parameter is set only when Twilio receives a forwarded call, but its value depends on the caller’s carrier including information when forwarding. Not all carriers support passing this information. |
Nesting Rules
You can’t nest any verbs within <Record> and you can’t nest <Record> within any other verbs.
See Also
Examples
Example 1: Simple Record
Twilio will execute the <Record> verb causing the caller to hear a beep and the recording to start. If the caller is silent for more than five seconds, hits the # key, or the recording maxlength time is hit, Twilio will make an HTTP POST request to the default action URL (ie. the current document URL) with the parameters RecordingUrl and RecordingDuration.
Example 2: Record a voicemail
This example shows a simple voicemail prompt. The caller is asked to leave a message at the beep. The <Record> verb beeps and begins recording up to 20 seconds of audio.
- If the caller speaks for less than 20 seconds and is then silent for five seconds, Twilio makes a GET request to the
actionURL. The<Say>verb is never reached. - If the caller speaks for the full 20 seconds, Twilio makes a GET request to the
actionURL. The<Say>verb is never reached.
Example 3: Transcribe a recording
Twilio will record the caller. When the recording is complete, Twilio will transcribe the recording and make an HTTP POST request to the transcribeCallback URL with a parameter containing a transcription of the recording.
Hints and advanced uses
- Twilio will trim leading and trailing silence from your audio files. This may cause the duration of the files to be slightly smaller than the time a caller spends recording them.
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