Voice

Programmable voice calls, SIP trunking, and AI-powered voice agents

Voice

Build programmable voice experiences with Orbit’s voice infrastructure powered by LiveKit. Make and receive calls, connect SIP trunks, deploy AI voice agents with real-time speech-to-text and text-to-speech, and record calls — all through a unified API.

Make an Outbound Call

curl -X POST https://orbit-api.devotel.io/api/v1/voice/calls \
  -H "X-API-Key: dv_live_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "to": "[phone]",
    "from": "[phone]",
    "webhook_url": "https://yourapp.com/webhooks/voice",
    "tts": {
      "text": "Hello! This is a call from Orbit.",
      "voice": "alloy"
    }
  }'

Connect to an AI Voice Agent

Route incoming calls to an AI agent for automated conversations:

curl -X POST https://orbit-api.devotel.io/api/v1/voice/calls \
  -H "X-API-Key: dv_live_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "to": "[phone]",
    "from": "[phone]",
    "agent_id": "agent_support_bot",
    "agent_config": {
      "greeting": "Hi, thanks for calling Acme support. How can I help?",
      "language": "en-US"
    }
  }'

Features

• Outbound calls — initiate calls programmatically to any phone number
• Inbound routing — route incoming calls to webhooks, agents, or SIP endpoints
• SIP trunking — connect your existing PBX infrastructure via SIP
• AI voice agents — deploy conversational AI agents powered by LangGraph
• Speech-to-text — real-time transcription via Deepgram Nova-3
• Text-to-speech — natural voice synthesis via Cartesia Sonic Turbo (40ms TTFA)
• Call recording — automatic or on-demand recording with secure storage
• DTMF input — collect keypad input for IVR menus
• Call transfer — warm and cold transfers to other numbers or agents
• Conferencing — multi-party calls with up to 50 participants

TTS Providers

Provider	Model	Latency	Best For
Cartesia	Sonic Turbo	~40ms TTFA	Real-time voice agents
ElevenLabs	Flash v2.5	~120ms TTFA	Multi-language, content generation

Call Status Flow

initiated → ringing → in_progress → completed (or failed / busy / no_answer)

Webhook Events

Orbit sends real-time events during call lifecycle:

Event	Description
call.initiated	Call has been placed
call.ringing	Destination is ringing
call.answered	Call was answered
call.completed	Call ended normally
call.failed	Call failed to connect
call.recording_ready	Recording is available for download