Create speech

Generates audio from input text (text-to-speech). Returns the audio file as binary data.

Authorization

bearerAuth

AuthorizationBearer <token>

Bearer token authentication using API keys

In: header

Request Body

application/json

TypeScript Definitions

Use the request body type in TypeScript.

model*string

ID of the speech generation (text-to-speech) model to use.

input*string

The text to synthesize into speech.

Length1 <= length

voice?string

The prebuilt voice to use. Defaults to the model's default voice when omitted.

response_format?string

The audio format of the returned audio. OpenAI models support mp3 (default), opus, aac, flac, wav and pcm. Gemini models emit PCM, so only wav (default) and pcm are supported.

Value in"wav" | "pcm" | "mp3" | "opus" | "aac" | "flac"

speed?number

Playback speed hint. Forwarded to OpenAI models; not applied by Gemini speech models.

Range0.25 <= value <= 4

instructions?string

Optional style/delivery instructions prepended to the input as a natural-language directive (e.g. 'Say cheerfully').

Response Body

`application/json`

curl -X POST "https://example.com/v1/audio/speech" \  -H "Content-Type: application/json" \  -d '{    "model": "gemini-2.5-flash-preview-tts",    "input": "Hello, welcome to LLM Gateway!"  }'

null

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

{
  "error": {
    "message": "string",
    "type": "string",
    "param": "string",
    "code": "string"
  }
}

Create speech

Authorization

Request Body

Response Body

200audio/wav

400application/json

401application/json

402application/json

403application/json

500application/json

502application/json

504application/json

`application/json`

`application/json`

`application/json`

`application/json`

`application/json`

`application/json`

`application/json`