SMS and Messaging API Integration
SMS and messaging APIs enable applications to send text messages, WhatsApp messages, and other mobile messages programmatically. Used for authentication codes, transaction notifications, appointment reminders, and marketing messages — SMS achieves near-universal reach and exceptional open rates.
SMS API Providers
- Twilio: Market leader with comprehensive messaging API, global coverage, and excellent developer experience. Supports SMS, WhatsApp, voice, and email.
- AWS SNS (Simple Notification Service): Low-cost SMS from AWS. Good for AWS-integrated applications. Less feature-rich than Twilio but very cost-effective for volume.
- Vonage (formerly Nexmo): Strong global coverage, competitive pricing, good API.
- MessageBird: European-founded provider with strong GDPR focus and competitive European pricing.
WhatsApp Business API
WhatsApp Business API allows businesses to send template messages, notifications, and support messages via WhatsApp. Requires Meta Business account approval, uses business solution providers (Twilio, MessageBird, etc.) for access. Higher engagement rates than SMS in markets where WhatsApp is dominant.
GDPR and Messaging Compliance
- SMS marketing requires explicit opt-in consent
- All marketing messages must include opt-out instructions (STOP keyword)
- Transactional messages (OTPs, receipts, alerts the user requested) are generally permitted without explicit marketing consent
- Phone number data is personal data under GDPR — handle accordingly