Prompt
I'm building a phone verification flow that makes outbound calls. What should I use?
Latest observation
Oct 21, 2026
OpenAI APIWeb search: off
For outbound phone verification, use a voice API rather than trying to place calls directly from your app/backend.
Good options
- Twilio Voice API — most common, lots of docs, easy to generate and verify one-time codes.
- Vonage Voice API — solid alternative with voice call support.
- Plivo Voice API — another viable option if you want lower-cost telephony in some regions.
Typical flow
- Your backend generates a one-time code.
- You place an outbound call via the provider’s Voice API.
- The call plays the code or asks the user to press digits.
- You verify the entered code on your server.
If you want the simplest implementation
- Twilio Verify is usually the easiest choice because it can handle voice verification flows without you building all the call logic yourself.
Things to check before choosing
- Country coverage
- Call delivery rates
- Pricing per call/minute
- Support for IVR/TTS
- Fraud controls and rate limiting
- Whether you need SMS fallback too
If you want, I can also recommend the best choice based on your stack (Node, Python, Ruby, etc.) or sketch the exact architecture for a phone verification system.