twilio-communications

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 a...

Twilio Communications

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 ([phone])
• 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 ([phone])"
            }

        # 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: Twilio

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)', 'Password reset verification', 'High-value transaction confirmation']

from twilio.rest import Client
from twilio.base.exceptions import TwilioRestException
import os
from enum import Enum
from typing import Optional

class VerifyChannel(Enum):
    SMS = "sms"
    CALL = "call"
    EMAIL = "email"
    WHATSAPP = "whatsapp"

class TwilioVerify:
    """
    Phone verification with Twilio Verify.
    Never store OTP codes - Twilio handles it.
    """

    def __init__(self, verify_service_sid: str = None):
        self.client = Client(
            os.environ["TWILIO_ACCOUNT_SID"],
            os.environ["TWILIO_AUTH_TOKEN"]
        )
        # Create a Verify Service in Twilio Console first
        self.service_sid = verify_service_sid or os.environ["TWILIO_VERIFY_SID"]

    def send_verification(
        self,
        to: str,
        channel: VerifyChannel = VerifyChannel.SMS,
        locale: str = "en"
    ) -> dict:
        """
        Send verification code to phone/email.

        Args:
            to: Phone number (E.164) or email
            channel: SMS, call, email, or whatsapp
            locale: Language code for message

        Returns:
            Verification status
        """
        try:
            verification = .client.verify \
                .v2 \
                .services(.service_sid) \
                .verifications \
                .create(
                    to=to,
                    channel=channel.value,
                    locale=locale
                )

             {
                : ,
                : verification.status,  
                : channel.value,
                : verification.valid
            }

         Twi