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5 min

Inbound Voice Call trigger

Answer the phone with a workflow. What fires before the call connects, what you know about the caller, and why this trigger has less time than any other.

A phone rings. Unlike a message, nobody is willing to wait — a caller gives you a second or two of silence before deciding something is broken. That single fact shapes everything about this trigger.

The Inbound Voice Call trigger starts a workflow when someone dials one of your numbers.

It can fire before the call is answered

The five settings, and the first two are prerequisites rather than choices.

integration_id

What it holds
Voice provider integration (Twilio, Exotel, Vobiz, etc.)

phone_numbers

What it holds
Phone numbers that trigger this workflow when called

call_answer_mode

What it holds
PreAnswer: Call NOT answered initially, connects only if Voice Inbound Call node reached | Answered: Call answered immediately | NOTE: Tata Tele ONLY supports 'Answered' mode (PreAnswer not available) One of: preanswer · answered Defaults to preanswer.

ringing_time

What it holds
Maximum ringing duration in seconds (stops when Voice Inbound Call node connects) Defaults to 30.

ringtone

What it holds
Audio played while workflow executes (before Voice Inbound Call node connects) One of: default_ring · silent · custom_url Defaults to default_ring.

preanswer

The workflow runs
While the phone is still ringing.
Which means
You can look the caller up, decide, and route — before anyone picks up. The default.

answered

The workflow runs
After the call connects.
Which means
Simpler, and you have already committed to answering.

Pre-answer is the interesting one. It is the difference between “answer, then work out who this is” and “know who this is, then decide whether to answer at all”. A known customer with an open ticket can go straight to their account manager; an unrecognised number can go to the general queue.

ringing_time is how long that window lasts — 30 seconds by default, which sounds generous and is not, because it is also how long the caller is listening to a ringtone.

What you know about the caller

{{voiceinboundtrigger_1.caller_phone}}

Holds
The number they called from.

{{voiceinboundtrigger_1.contact}}

Holds
The matched CRM contact, if the number is known.

{{voiceinboundtrigger_1.call_sid}}

Holds
The provider's id for this call — what ties a recording or transcript back to it.

{{voiceinboundtrigger_1.direction}}

Holds
Inbound or outbound.

{{voiceinboundtrigger_1.provider}}

Holds
Which telephony provider handled it.

As with WhatsApp, the contact match is done for you. A caller who exists in your CRM arrives identified, which is the whole basis for routing them somewhere sensible.

Everything here is on a clock

A slow workflow is a bad phone experience, and it is not recoverable. A database change trigger can take four seconds and nobody notices. Here, four seconds is a caller wondering whether the line is dead. Keep the pre-answer path to the minimum — a lookup and a decision. Anything slow (an AI summary, an external API, a report) belongs after the call, not in front of it.

What this needs before it can run

Two things, and both are set up by a person rather than by a workflow:

  • A telephony integration — the integration_id. Without one there is no phone to ring.
  • At least one number — phone_numbers lists which of your numbers this workflow answers. An organisation with a sales line and a support line runs a different workflow on each.

Why this lesson has no diagram. Both of those fields are required, so a voice workflow cannot even be created in an organisation without telephony connected — which is the honest state of most organisations reading this. Rather than show you a workflow built on invented numbers, the page stops at the configuration. Everything above is read from the node's own schema.

Where it leads

On its own this trigger only tells you the phone rang. What happens next — greeting the caller, understanding them, transferring to a person — is the Voice module: the Voice Agent that talks, the Voice Response that speaks, and Transfer Call that hands over.

Try it

  1. Open the node in the builder even if you have no telephony connected — the required fields tell you the prerequisites more clearly than any list.
  2. Decide, for your own business, what you would want to happen in the preanswer window. That decision is the design; the nodes are easy.
  3. Write down which numbers would need different workflows. That answers whether you need one workflow or several.

Next: the webhook — the third family, where the thing contacting you is another system rather than a person.

Try this in Expedify →

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