OpenAI TTS

OpenAI TTS is supported in Burki through the openai TTS provider. Use it when you already use OpenAI keys or want GPT-4o mini TTS voice instructions.

Quick Setup

Get API Key

Create an OpenAI API key from the OpenAI dashboard.

Configure in Burki

Select openai as the TTS provider and add the API key at the assistant or organization level.

Choose Model and Voice

Pick a supported model_id, voice_id, and optional speed/instructions settings.

Configuration

{
  "tts_settings": {
    "provider": "openai",
    "voice_id": "alloy",
    "model_id": "gpt-4o-mini-tts",
    "provider_config": {
      "speed": 1.0,
      "instructions": "Speak warmly and clearly, like a helpful support agent."
    }
  }
}

Option	Type	Description
`provider`	string	Use `openai`
`voice_id`	string	OpenAI voice ID
`model_id`	string	`tts-1`, `tts-1-hd`, `gpt-4o-mini-tts`, or pinned GPT-4o mini TTS snapshot
`speed`	number	Speaking speed, clamped between `0.25` and `4.0`
`instructions`	string	Voice style instructions for `gpt-4o-mini-tts*` models

Supported Models

Model ID	Notes
`tts-1`	Standard OpenAI TTS model optimized for speed
`tts-1-hd`	Higher quality OpenAI TTS model
`gpt-4o-mini-tts`	GPT-4o mini TTS model with instruction support
`gpt-4o-mini-tts-2025-12-15`	Pinned GPT-4o mini TTS snapshot configured in the backend

Supported Voices

Voice ID	Description
`alloy`	Balanced and clear
`echo`	Deep and resonant
`fable`	Warm and expressive
`onyx`	Strong and authoritative
`nova`	Bright and energetic
`shimmer`	Soft and gentle
`ash`	Natural and conversational
`ballad`	Melodic and expressive
`coral`	Warm and friendly
`sage`	Calm and wise
`verse`	Smooth and articulate
`marin`	Clear and professional
`cedar`	Warm and natural

Runtime Behavior

Burki requests PCM audio from OpenAI and converts it for the current telephony path.
gpt-4o-mini-tts* models support the instructions field.
HD telephony providers use linear16 at 16 kHz where supported; Twilio-style paths use µ-law at 8 kHz.
Sentence buffering is used so the first audio chunk can start quickly without waiting for the entire LLM response.

When to Use OpenAI TTS

You want a simple provider stack with OpenAI for both LLM and TTS.
You need model-level voice instructions.
You prefer built-in voices over custom voice cloning.

For broader multilingual voice cloning, compare ElevenLabs, Cartesia, and Inworld.

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OpenAI TTS

OpenAI TTS

Quick Setup

Configuration

Supported Models

Supported Voices

Runtime Behavior

When to Use OpenAI TTS

OpenAI TTS

​Quick Setup

​Configuration

​Supported Models

​Supported Voices

​Runtime Behavior

​When to Use OpenAI TTS

Quick Setup

Configuration

Supported Models

Supported Voices

Runtime Behavior

When to Use OpenAI TTS