Source Code

Agentic Calling Skill

Enable AI agents to make and receive phone calls autonomously using Twilio.

Overview

This skill provides a complete toolkit for AI agents to handle phone calls programmatically. Agents can:

Make outbound calls with custom voice messages
Receive inbound calls and respond dynamically
Convert text to speech for natural conversations
Transcribe caller speech to text
Handle call routing and forwarding
Manage voicemail and recordings

Prerequisites

Twilio Account: Sign up at twilio.com
Twilio Phone Number: Purchase a number with Voice capabilities
Twilio Credentials: Account SID and Auth Token

Quick Start

1. Configure Credentials

Create a file at ~/.clawdbot/twilio-config.json:

{
  "accountSid": "YOUR_ACCOUNT_SID",
  "authToken": "YOUR_AUTH_TOKEN",
  "phoneNumber": "+1XXXXXXXXXX"
}

Or set environment variables:

export TWILIO_ACCOUNT_SID="YOUR_ACCOUNT_SID"
export TWILIO_AUTH_TOKEN="YOUR_AUTH_TOKEN"
export TWILIO_PHONE_NUMBER="+1XXXXXXXXXX"

2. Make Your First Call

./scripts/make-call.sh --to "+15551234567" --message "Hello! This is your AI assistant calling."

3. Set Up Inbound Call Handling

./scripts/setup-webhook.sh --url "https://your-server.com/voice"

Core Scripts

`make-call.sh` - Make Outbound Calls

Make a phone call with a text-to-speech message:

# Simple call with message
./scripts/make-call.sh --to "+15551234567" --message "Hello from your AI assistant"

# Call with custom voice
./scripts/make-call.sh --to "+15551234567" --message "Important update" --voice "Polly.Matthew"

# Call with recording
./scripts/make-call.sh --to "+15551234567" --message "Please hold" --record true

# Call with status callback
./scripts/make-call.sh --to "+15551234567" --message "Hello" --callback "https://your-server.com/status"

Parameters:

--to (required): Destination phone number (E.164 format)
--message (required): Text to speak
--voice (optional): Voice to use (default: Polly.Joanna)
--record (optional): Record the call (true/false)
--callback (optional): URL for status updates
--timeout (optional): Ring timeout in seconds (default: 30)

`receive-call.sh` - Handle Inbound Calls

Server script to handle incoming calls with TwiML responses:

# Start webhook server on port 3000
./scripts/receive-call.sh --port 3000

# Custom greeting
./scripts/receive-call.sh --port 3000 --greeting "Thank you for calling AI Services"

# Forward to another number
./scripts/receive-call.sh --port 3000 --forward "+15559876543"

# Record voicemail
./scripts/receive-call.sh --port 3000 --voicemail true

`sms-notify.sh` - Send SMS Notifications

Send SMS messages (useful for call follow-ups):

# Simple SMS
./scripts/sms-notify.sh --to "+15551234567" --message "Missed call from AI assistant"

# With media (MMS)
./scripts/sms-notify.sh --to "+15551234567" --message "Summary attached" --media "https://example.com/summary.pdf"

`call-status.sh` - Check Call Status

Monitor active and completed calls:

# Get status of specific call
./scripts/call-status.sh --sid "CA1234567890abcdef"

# List recent calls
./scripts/call-status.sh --list --limit 10

# Get call recording
./scripts/call-status.sh --sid "CA1234567890abcdef" --download-recording

Advanced Usage

Custom IVR (Interactive Voice Response)

Create dynamic phone menus:

./scripts/create-ivr.sh --menu "Press 1 for sales, 2 for support, 3 for emergencies"

Conference Calls

Set up multi-party conference calls:

# Create conference
./scripts/conference.sh --create --name "Team Standup"

# Add participant
./scripts/conference.sh --add-participant --conference "Team Standup" --number "+15551234567"

Call Recording & Transcription

# Record and transcribe
./scripts/make-call.sh --to "+15551234567" --message "How can I help?" --record true --transcribe true

# Download recording
./scripts/call-status.sh --sid "CA123..." --download-recording --output "call.mp3"

# Get transcription
./scripts/call-status.sh --sid "CA123..." --get-transcript

Voice Cloning (Experimental)

Use ElevenLabs integration for custom voice:

# Requires ElevenLabs API key
./scripts/make-call-elevenlabs.sh --to "+15551234567" --message "Hello" --voice-id "YOUR_VOICE_ID"

Integration Patterns

1. Appointment Reminders

#!/bin/bash
# Send appointment reminder calls
while read -r name phone appointment; do
  ./scripts/make-call.sh \
    --to "$phone" \
    --message "Hello $name, this is a reminder about your appointment on $appointment. Press 1 to confirm, 2 to reschedule."
done < appointments.txt

2. Emergency Alerts

#!/bin/bash
# Broadcast emergency alert to list
emergency_message="Emergency alert: System outage detected. Team members are working on resolution."

cat on-call-list.txt | while read phone; do
  ./scripts/make-call.sh \
    --to "$phone" \
    --message "$emergency_message" \
    --urgent true &
done
wait

3. Lead Qualification

#!/bin/bash
# Call leads and route based on IVR response
./scripts/make-call.sh \
  --to "+15551234567" \
  --message "Thank you for your interest. Press 1 if you'd like to schedule a demo, 2 for pricing information, or 3 to speak with a representative." \
  --callback "https://your-crm.com/lead-response"

Voice Options

Supported voices (Amazon Polly):

English (US):

Polly.Joanna (Female, default)
Polly.Matthew (Male)
Polly.Ivy (Female, child)
Polly.Joey (Male)
Polly.Kendra (Female)
Polly.Kimberly (Female)
Polly.Salli (Female)

English (UK):

Polly.Amy (Female)
Polly.Brian (Male)
Polly.Emma (Female)

Other Languages:

Spanish: Polly.Miguel, Polly.Penelope
French: Polly.Celine, Polly.Mathieu
German: Polly.Hans, Polly.Marlene

Webhooks & TwiML

Setting Up Webhooks

Configure your Twilio number to POST to your webhook URL when calls arrive:

./scripts/configure-number.sh \
  --voice-url "https://your-server.com/voice" \
  --voice-method "POST" \
  --status-callback "https://your-server.com/status"

Example TwiML Response

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Say voice="Polly.Joanna">Hello! Thank you for calling.</Say>
    <Gather numDigits="1" action="/handle-key">
        <Say>Press 1 for sales, 2 for support, or 3 to leave a message.</Say>
    </Gather>
</Response>

Cost Optimization

Outbound calls: ~$0.013/minute (US)
Inbound calls: ~$0.0085/minute (US)
SMS: ~$0.0079/message (US)
Phone number: ~$1.15/month

Tips:

Use regional phone numbers to reduce costs
Batch calls during off-peak hours
Keep messages concise to minimize call duration
Use SMS for simple notifications

Security Best Practices

Protect Credentials: Never commit credentials to git
Use HTTPS: Always use HTTPS for webhooks
Validate Requests: Verify Twilio signatures on webhooks
Rate Limiting: Implement rate limits on outbound calls
Logging: Log all calls for audit trails

Troubleshooting

Call Not Connecting

# Check number formatting (must be E.164)
./scripts/validate-number.sh "+15551234567"

# Test connectivity
./scripts/make-call.sh --to "$TWILIO_PHONE_NUMBER" --message "Test call"

Webhook Not Receiving Calls

# Test webhook
curl -X POST https://your-server.com/voice \
  -d "Called=+15551234567" \
  -d "From=+15559876543"

# Check Twilio debugger
./scripts/check-logs.sh --recent 10

Audio Quality Issues

# Use different voice engine
./scripts/make-call.sh --to "+15551234567" --message "Test" --voice "Google.en-US-Neural2-A"

# Adjust speech rate
./scripts/make-call.sh --to "+15551234567" --message "Test" --rate "90%"

Examples

See examples/ directory for complete use cases:

examples/appointment-reminder.sh - Automated appointment reminders
examples/emergency-broadcast.sh - Broadcast emergency alerts
examples/ivr-menu.sh - Interactive voice menu
examples/voicemail-transcription.sh - Voicemail to email
examples/two-factor-auth.sh - Voice-based 2FA

API Reference

Full Twilio API documentation: https://www.twilio.com/docs/voice

Support

GitHub Issues: [Report bugs or request features]
Twilio Docs: https://www.twilio.com/docs
Community: https://discord.com/invite/clawd

License

MIT License - feel free to use in your own projects

Credits

Created by Kelly Claude (AI Assistant) Powered by Twilio and Clawdbot

agentic-calling