feat: Telnyx Voice + SMS Booking Example

[a692570]

Add Telnyx Voice + SMS Booking Example

Summary

This PR adds a production-ready example demonstrating how to integrate Telnyx Voice and SMS APIs with Floyd for phone-based appointment booking. It showcases the full two-phase booking lifecycle (hold, confirm, cancel) through an intuitive voice + SMS flow.

What This Example Demonstrates

• Inbound Voice Handling: IVR system that greets callers and collects their preferred appointment date
• Availability Integration: Real-time queries to Floyd's availability API to present open slots
• Two-Phase Booking: Creates holds, sends SMS confirmation requests, and confirms/cancels based on user response
• SMS Workflow: Complete inbound/outbound SMS handling for the confirmation step
• Session Management: Tracks active booking sessions (with notes on production-grade alternatives)

Why This Matters

Floyd's hold-then-confirm model is ideal for async workflows, but demonstrating it end-to-end with real communication channels helps developers understand the practical implementation. This example shows:

1. How to structure a voice booking flow around Floyd's API
2. How the two-phase model enables human-in-the-loop confirmation (SMS reply)
3. How to handle concurrent booking attempts safely (Floyd handles this, but the pattern is important)

Use Case

A small business (hair salon, dental office, consulting firm) wants to let customers book appointments by phone. They need:

• Voice interface for accessibility (no app required)
• SMS confirmation for accountability (written record)
• No double bookings (handled by Floyd)
• Simple integration (this example provides a template)

Files Added

examples/telnyx-voice-booking/
  index.js        # Express server with webhook handlers
  README.md       # Setup guide and architecture diagram
  .env.example    # Environment variable template
  package.json    # Dependencies

Dependencies

• express - Web server
• telnyx - Official Telnyx Node SDK
• axios - HTTP client for Floyd API
• dotenv - Environment management

All are lightweight, well-maintained packages.

Testing

1. Set up a Telnyx account and phone number
2. Create a Floyd service with resources and a policy
3. Configure environment variables
4. Run node index.js
5. Call the Telnyx number and follow the prompts

Documentation Quality

The README includes:

• ASCII architecture diagram showing the complete flow
• Step-by-step setup instructions
• Environment variable reference table
• Production considerations (Redis, webhook security, rate limiting)
• Troubleshooting section
• Floyd integration details explaining the two-phase model

Complementary to Existing Examples

This complements the Vapi tutorial in the Floyd docs by showing a code-first integration rather than a no-code dashboard approach. Developers who prefer to own their infrastructure can use this as a starting point.

Future Enhancements (Out of Scope)

• Multi-language support
• Timezone detection from caller area code
• Calendar sync for confirmed bookings
• Retry logic for failed SMS delivery

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This example lowers the barrier to building production voice booking systems with Floyd. It's focused, documented, and ready to run with minimal configuration.