Make.com Voice Agents: Integrate AI Phone Systems Into Your Scenarios

Voice AI Stack with Make.com

Building voice agents in Make.com:

• Vapi — Voice AI platform; handles call orchestration, STT, TTS
• Twilio — Telephony; Make has native Twilio module
• ElevenLabs — Natural-sounding TTS voices
• Claude API — AI brain for voice agent reasoning
• Make.com — Orchestrates post-call workflows (CRM updates, follow-ups)

Vapi Webhook Integration

Vapi sends webhook events that Make.com processes:

Set up in Vapi:

• Assistant settings → Server URL → your Make.com webhook URL

Events Make.com receives:

• call.started — new inbound call
• call.ended — call completed (with transcript + summary)
• tool_calls — agent wants to execute a tool (e.g., lookup customer, book meeting)
• hang — call detected hang state

Make.com Webhook trigger:

1. Add Webhook module to your Scenario
2. Copy the webhook URL
3. Paste into Vapi's server URL setting

Post-Call Workflow

The most common Vapi + Make.com integration: process call results after the call ends.

Scenario: Post-call CRM update

1. Webhook trigger: Receive call.ended event from Vapi
2. Filter: Only process if status = "ended" (not cancelled, failed, etc.)
3. Tools → Parse JSON: Extract transcript, summary, call duration, caller number
4. HTTP (Claude): Analyse call

1. Parse JSON
2. Router: Branch by outcome

- interested → HubSpot: create deal + Slack alert to sales rep - callback_requested → HubSpot: create follow-up task + schedule callback - voicemail → Airtable: log + schedule retry in 24h - not_interested → HubSpot: update contact status

1. HubSpot: Log call activity with transcript and AI summary

Outbound Call Campaign

Scenario: Launch outbound campaign

1. Trigger: Airtable new row (campaign launch row added)
2. Airtable: Get all leads in the campaign list
3. Iterator: For each lead
4. HTTP (Vapi API): Initiate outbound call

1. Wait: 5 minutes before next call (rate limiting)
2. Airtable: Log call initiated + Vapi call ID for tracking

Tool Call Handling

When a Vapi voice agent needs real-time data (e.g., check availability, look up order status), Make.com handles the tool call:

Vapi tool call → Make.com → external system → return to Vapi

1. Webhook: Receive tool_calls event from Vapi
2. Router: Switch on function name

- check_availability → Calendly API: get open slots - lookup_order → Database: query order status - book_appointment → Calendly API: book + HubSpot: create deal

1. HTTP (Vapi): Return tool result

This happens in under 1 second — the voice agent waits for the response.

Appointment Reminder Calls

Automated voice reminders:

1. Schedule: Hourly
2. Airtable: Find appointments in next 24 hours with no reminder sent
3. Iterator: For each appointment
4. HTTP (Vapi): Initiate reminder call with custom script
5. Vapi webhook → separate Scenario: Handle response (1 = confirm, 2 = reschedule)
6. Airtable: Update appointment status
7. Calendar: Confirm or cancel based on response

SMS Fallback for Missed Calls

If the voice agent can't reach someone:

1. Vapi webhook: Call ended with outcome = voicemail or no answer
2. Twilio: Send SMS follow-up

1. Make.com (SMS reply webhook): Process reply
2. If YES: schedule callback; if no reply in 24h: add to lower-priority list

Recommended Tools

• Make.com — Voice workflow orchestration
• Vapi — Voice AI platform
• Twilio — Telephony infrastructure (native module)
• ElevenLabs — Natural voices for Vapi agents
• Claude API — AI for call analysis
• HubSpot — CRM for post-call updates