AssemblyAI · Voice model

TTS 1

assemblyai/assemblyai-tts-1

Voice

Released Oct 28, 2026

AssemblyAI TTS 1 is a text-to-speech model from AssemblyAI. It is suited for voice agents, narration, and multilingual applications, and draws on a public library of several thousand voices across...

Specifications

Input: text, up to 20,000 characters per call
Output: mp3 (default) or raw pcm
Voice: `voice`, default aai-antonioluis · aai-antonioluis, aai-audrey, aai-carrie, aai-constanza, aai-donatien, aai-ernest, aai-ewald, aai-gunther, aai-hailey, aai-jorg, aai-kyla, aai-magdalena, … (20 in all)
Billing: per character of input text

Use it

POST /api/v1/audio/speech · MCP speak · full reference

curl https://omnirail.org/api/v1/audio/speech \
  -H "Authorization: Bearer $OMNIRAIL_KEY" -H "Content-Type: application/json" \
  -d '{"model":"assemblyai/assemblyai-tts-1","input":"Hello from OmniRail. Every model, one key.","response_format":"mp3"}' \
  --output hello.mp3