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CloudVNO

Voice Overview

Introduction to CloudVNO's Programmable Voice API — make and receive calls, SIP trunking, and call control.

What is Programmable Voice?

CloudVNO's Voice API lets you make and receive phone calls, build interactive voice menus (IVR), record calls, transcribe speech, and control calls in real time — all via REST API and webhooks.

Core Concepts

Call SID

Every call has a unique SID (e.g., CA1a2b3c4d...). Use it to monitor status, retrieve recordings, and control active calls.

Call Status Lifecycle

queued → ringing → in-progress → completed
                               └→ busy
                               └→ no-answer
                               └→ failed
                               └→ canceled

Call Control via Webhooks

When a call connects, CloudVNO fetches instructions from your webhook URL. Your server responds with XML (TwiML-compatible) that tells CloudVNO what to do:

  • <Say> — Text-to-speech
  • <Play> — Play an audio file
  • <Gather> — Collect DTMF input
  • <Record> — Record the call
  • <Dial> — Connect to another number
  • <Hangup> — End the call
  • <Redirect> — Fetch new instructions

SIP Trunking

Connect your own PBX or VoIP infrastructure to CloudVNO using SIP trunking. Ideal for AI voice agents, contact centers, and custom phone systems.

STIR/SHAKEN

CloudVNO supports STIR/SHAKEN attestation for all US outbound calls:

  • Full Attestation (A): You own the calling number and authorized the call
  • Partial Attestation (B): You verified the customer's right to use the number
  • Gateway Attestation (C): Call originated outside your network

Proper attestation significantly improves answer rates and reduces spam labeling.