---

name: twilio-communications description: "Build communication features with Twilio: SMS messaging, voice calls, WhatsApp Business API, and user verification (2FA). Covers the full spectrum from simple notifications to complex IVR systems and multi-channel authentication." risk: unknown source: vibeship-spawner-skills (Apache 2.0) date_added: 2026-02-27

Twilio Communications

Build communication features with Twilio: SMS messaging, voice calls, WhatsApp Business API, and user verification (2FA). Covers the full spectrum from simple notifications to complex IVR systems and multi-channel authentication. Critical focus on compliance, rate limits, and error handling.

Patterns

SMS Sending Pattern

Basic pattern for sending SMS messages with Twilio. Handles the fundamentals: phone number formatting, message delivery, and delivery status callbacks.

Key considerations:

• Phone numbers must be in E.164 format (+1234567890)
• Default rate limit: 80 messages per second (MPS)
• Messages over 160 characters are split (and cost more)
• Carrier filtering can block messages (especially to US numbers)

When to use: Sending notifications to users,Transactional messages (order confirmations, shipping),Alerts and reminders

from twilio.rest import Client from twilio.base.exceptions import TwilioRestException import os import re

class TwilioSMS: """ SMS sending with proper error handling and validation. """

def __init__(self):
    self.client = Client(
        os.environ["TWILIO_ACCOUNT_SID"],
        os.environ["TWILIO_AUTH_TOKEN"]
    )
    self.from_number = os.environ["TWILIO_PHONE_NUMBER"]

def validate_e164(self, phone: str) -> bool:
    """Validate phone number is in E.164 format."""
    pattern = r'^\+[1-9]\d{1,14}$'
    return bool(re.match(pattern, phone))

def send_sms(
    self,
    to: str,
    body: str,
    status_callback: str = None
) -> dict:
    """
    Send an SMS message.

    Args:
        to: Recipient phone number in E.164 format
        body: Message text (160 chars = 1 segment)
        status_callback: URL for delivery status webhooks

    Returns:
        Message SID and status
    """
    # Validate phone number format
    if not self.validate_e164(to):
        return {
            "success": False,
            "error": "Phone number must be in E.164 format (+1234567890)"
        }

    # Check message length (warn about segmentation)
    segment_count = (len(body) + 159) // 160
    if segment_count > 1:
        print(f"Warning: Message will be sent as {segment_count} segments")

    try:
        message = self.client.messages.create(
            to=to,
            from_=self.from_number,
            body=body,
            status_callback=status_callback
        )

        return {
            "success": True,
            "message_sid": message.sid,
            "status": message.status,
            "segments": segment_count
        }

    except TwilioRestException as e:
        return self._handle_error(e)

def _handle_error(self, error: TwilioRestException) -> dict:
    """Handle Twilio-specific errors."""
    error_handlers = {
        21610: "Recipient has opted out. They must reply START.",
        21614: "Invalid 'To' phone number format.",
        21211: "'From' phone number is not valid.",
        30003: "Phone is unreachable (off, airplane mode, no signal).",
        30005: "Unknown destination (invalid number or landline).",
        30006: "Landline or unreachable carrier.",
        30429: "Rate limit exceeded. Implement exponential backoff.",
    }

    return {
        "success": False,
        "error_code": error.code,
        "error": error_handlers.get(error.code, error.msg),
        "details": str(error)
    }

Usage

sms = TwilioSMS() result = sms.send_sms( to="+14155551234", body="Your order #1234 has shipped!", status_callback="https://your-app.com/webhooks/twilio/status" )

Anti_patterns

• Not validating E.164 format before sending
• Hardcoding Twilio credentials in code
• Ignoring delivery status callbacks
• Not handling the opted-out (21610) error

Twilio Verify Pattern (2FA/OTP)

Use Twilio Verify for phone number verification and 2FA. Handles code generation, delivery, rate limiting, and fraud prevention.

Key benefits over DIY OTP:

• Twilio manages code generation and expiration
• Built-in fraud prevention (saved customers $82M+ blocking 747M attempts)
• Handles rate limiting automatically
• Multi-channel: SMS, Voice, Email, Push, WhatsApp

Google found SMS 2FA blocks "100% of automated bots, 96% of bulk phishing attacks, and 76% of targeted attacks."

When to use: User phone number verification at signup,Two-factor authentication (2FA),Passwor