Twilio Voice

Twilio Voice is a powerful cloud communications platform that enables businesses to make, receive, and manage phone calls programmatically through a simple API.

Twilio Voice provides a robust API for building sophisticated voice applications with global reach. With coverage in over 100 countries, carrier-grade reliability, and a 99.95% uptime SLA, Twilio has established itself as the industry leader in programmable voice communications.

Key features of Twilio Voice include:

Global Voice Network: Make and receive calls worldwide with local phone numbers in multiple countries
Programmable Call Control: Use TwiML to control call flow, record conversations, gather DTMF input, and implement IVR systems
Advanced Capabilities: Speech recognition, text-to-speech, call forwarding, conferencing, and answering machine detection
Real-time Analytics: Track call quality, duration, costs, and optimize your voice applications

In Sim, the Twilio Voice integration enables your agents to leverage these powerful voice capabilities as part of their workflows. This creates opportunities for sophisticated customer engagement scenarios like appointment reminders, verification calls, automated support lines, and interactive voice response systems. The integration bridges the gap between your AI workflows and voice communication channels, enabling your agents to deliver timely, relevant information directly through phone calls. By connecting Sim with Twilio Voice, you can create intelligent agents that engage customers through their preferred communication channel, enhancing the user experience while automating routine calling tasks.

Parameter	Type	Required	Description
`to`	string	Yes	Phone number to call in E.164 format (e.g., +14155551234)
`from`	string	Yes	Your Twilio phone number to call from in E.164 format (e.g., +14155559876)
`url`	string	No	Webhook URL that returns TwiML instructions for the call (e.g., https://example.com/twiml\)
`twiml`	string	No	TwiML instructions to execute. Use square brackets instead of angle brackets (e.g., [Response][Say]Hello[/Say][/Response])
`statusCallback`	string	No	Webhook URL for call status updates
`statusCallbackMethod`	string	No	HTTP method for status callback (GET or POST)
`accountSid`	string	Yes	Twilio Account SID
`authToken`	string	Yes	Twilio Auth Token
`record`	boolean	No	Whether to record the call
`recordingStatusCallback`	string	No	Webhook URL for recording status updates
`timeout`	number	No	Time to wait for answer before giving up (seconds, default: 60)
`machineDetection`	string	No	Answering machine detection: Enable or DetectMessageEnd

Output

Parameter	Type	Description
`success`	boolean	Whether the call was successfully initiated
`callSid`	string	Unique identifier for the call
`status`	string	Call status (queued, ringing, in-progress, completed, etc.)
`direction`	string	Call direction (outbound-api)
`from`	string	Phone number the call is from
`to`	string	Phone number the call is to
`duration`	number	Call duration in seconds
`price`	string	Cost of the call
`priceUnit`	string	Currency of the price
`error`	string	Error message if call failed

`twilio_voice_list_calls`

Retrieve a list of calls made to and from an account.

Input

Parameter	Type	Required	Description
`accountSid`	string	Yes	Twilio Account SID
`authToken`	string	Yes	Twilio Auth Token
`to`	string	No	Filter by calls to this phone number in E.164 format (e.g., +14155551234)
`from`	string	No	Filter by calls from this phone number in E.164 format (e.g., +14155559876)
`status`	string	No	Filter by call status (e.g., queued, ringing, in-progress, completed, busy, failed, no-answer, canceled)
`startTimeAfter`	string	No	Filter calls that started on or after this date (YYYY-MM-DD)
`startTimeBefore`	string	No	Filter calls that started on or before this date (YYYY-MM-DD)
`pageSize`	number	No	Number of records to return (max 1000, default 50)

Output

Parameter	Type	Description
`success`	boolean	Whether the calls were successfully retrieved
`calls`	array	Array of call objects
`total`	number	Total number of calls returned
`page`	number	Current page number
`pageSize`	number	Number of calls per page
`error`	string	Error message if retrieval failed

`twilio_voice_get_recording`

Retrieve call recording information and transcription (if enabled via TwiML).

Input

Parameter	Type	Required	Description
`recordingSid`	string	Yes	Recording SID to retrieve (e.g., RExxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)
`accountSid`	string	Yes	Twilio Account SID
`authToken`	string	Yes	Twilio Auth Token

Output

Parameter	Type	Description
`success`	boolean	Whether the recording was successfully retrieved
`recordingSid`	string	Unique identifier for the recording
`callSid`	string	Call SID this recording belongs to
`duration`	number	Duration of the recording in seconds
`status`	string	Recording status (completed, processing, etc.)
`channels`	number	Number of channels (1 for mono, 2 for dual)
`source`	string	How the recording was created
`mediaUrl`	string	URL to download the recording media file
`file`	file	Downloaded recording media file
`price`	string	Cost of the recording
`priceUnit`	string	Currency of the price
`uri`	string	Relative URI of the recording resource
`transcriptionText`	string	Transcribed text from the recording (if available)
`transcriptionStatus`	string	Transcription status (completed, in-progress, failed)
`transcriptionPrice`	string	Cost of the transcription
`transcriptionPriceUnit`	string	Currency of the transcription price
`error`	string	Error message if retrieval failed

Parameter	Type	Required	Description
`accountSid`	string	Yes	Your Twilio Account SID from the Twilio Console
`authToken`	string	Yes	Your Twilio Auth Token for webhook signature verification
`twimlResponse`	string	No	TwiML instructions to return immediately to Twilio. Use square brackets instead of angle brackets (e.g., [Response] instead of <Response>). This controls what happens when the call comes in (e.g., play a message, record, gather input). Your workflow will execute in the background.

Output

Parameter	Type	Description
`callSid`	string	Unique identifier for this call
`accountSid`	string	Twilio Account SID
`from`	string	Caller's phone number (E.164 format)
`to`	string	Recipient phone number (your Twilio number)
`callStatus`	string	Status of the call (queued, ringing, in-progress, completed, etc.)
`direction`	string	Call direction: inbound or outbound
`apiVersion`	string	Twilio API version
`callerName`	string	Caller ID name if available
`forwardedFrom`	string	Phone number that forwarded this call
`digits`	string	DTMF digits entered by caller (from <Gather>)
`speechResult`	string	Speech recognition result (if using <Gather> with speech)
`recordingUrl`	string	URL of call recording if available
`recordingSid`	string	Recording SID if available
`called`	string	Phone number that was called (same as "to")
`caller`	string	Phone number of the caller (same as "from")
`toCity`	string	City of the called number
`toState`	string	State/province of the called number
`toZip`	string	Zip/postal code of the called number
`toCountry`	string	Country of the called number
`fromCity`	string	City of the caller
`fromState`	string	State/province of the caller
`fromZip`	string	Zip/postal code of the caller
`fromCountry`	string	Country of the caller
`calledCity`	string	City of the called number (same as toCity)
`calledState`	string	State of the called number (same as toState)
`calledZip`	string	Zip code of the called number (same as toZip)
`calledCountry`	string	Country of the called number (same as toCountry)
`callerCity`	string	City of the caller (same as fromCity)
`callerState`	string	State of the caller (same as fromState)
`callerZip`	string	Zip code of the caller (same as fromZip)
`callerCountry`	string	Country of the caller (same as fromCountry)
`callToken`	string	Twilio call token for authentication
`raw`	string	Complete raw webhook payload from Twilio as JSON string

Twilio Voice

Usage Instructions

Actions

`twilio_voice_make_call`

Input

Output

`twilio_voice_list_calls`

Input

Output

`twilio_voice_get_recording`

Input

Output

Triggers

Twilio Voice Webhook

Configuration

Output

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