twilio-communications

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)"
        }