AI voice infrastructure

Speech in. Reasoning. Speech out. One pipeline, fully owned.

Kulatel is a self-hosted voice AI stack — speech-to-text, reasoning, and text-to-speech orchestrated over real-time call audio. No rented platform in between, no per-minute markup, no black box.

deepgram · gpt-4o · elevenlabs · twilio media streams
call_pipeline.log live
01
Media stream
twilio ws
02
Speech to text
deepgram
03
Reasoning
gpt-4o
04
Text to speech
elevenlabs

Renting a voice platform works — until the bill, the limits, or the roadmap doesn't.

Vapi and similar platforms are a fast way to ship a voice agent. Kulatel exists for the calls where we needed more control than a rented platform gives us — and it now runs interchangeably alongside Vapi, per project.

Renting a platform

Fast to start

  • Per-minute pricing set by the vendor
  • Conference transfers limited to what's exposed
  • Voicemail detection, cost tracking bolted on or missing
  • Roadmap and uptime outside our hands
Kulatel

Built for control

  • Deepgram + GPT-4o + ElevenLabs, priced at cost
  • Custom conference bridging for live agent transfers
  • Async AMD voicemail detection, built in
  • Whisper-based conference transcription and accurate cost tracking

Same job as a rented platform. Full visibility into how it's done.

TRANSFERS

Conference bridging

Live calls hand off to a human agent through a real conference bridge, not a blind transfer.

DETECTION

Async voicemail detection

AMD runs without blocking the call, so the agent responds the moment a real person picks up.

TRANSCRIPTS

Whisper transcription

Every conference call is transcribed for the deal jacket — searchable, timestamped, attached to the lead.

COST

Accurate cost tracking

Twilio usage is tracked per call, per project, so cost-per-lead is a real number, not an estimate.

ORCHESTRATION

Node.js media service

A dedicated microservice handles the Twilio WebSocket stream end to end, independent of the main app.

FLEXIBILITY

Runs alongside Vapi

Either stack can be selected per project or per dealership — Kulatel isn't a forced replacement.

CURRENTLY POWERING VOICE ON
Mobiunion MadCars MadRent