Inference

Text to speech

OpenRouter's text-to-speech API: one text in, the whole audio out as MP3 or raw PCM, never streamed. A call bills the input's characters, and settles before the first byte is sent. The answer has no JSON body, so its cost is in the generation record that X-Generation-Id names. GET /api/v1/models?output_modalities=speech lists the models your key can call, each with its supported_voices, default_voice and speech_speed.

POST/api/v1/audio/speech

Your key

Request

curl -X POST https://api.llm.buzz/api/v1/audio/speech \
  -H "Authorization: Bearer $LLM_BUZZ_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "hexgrad/kokoro-82m",
  "input": "Your order has shipped.",
  "voice": "af_heart",
  "response_format": "mp3"
}'

Response

{
  "error": {
    "code": 400,
    "message": "...",
    "metadata": {
      "error_type": "invalid_request",
      "gateway_code": "invalid_request",
      "param": "messages"
    }
  }
}

{
  "error": {
    "code": 401,
    "message": "A valid gateway Bearer key is required. Send the virtual key as 'Authorization: Bearer <key>'.",
    "metadata": {
      "error_type": "authentication",
      "gateway_code": "invalid_key"
    }
  }
}

{
  "error": {
    "code": 402,
    "message": "...",
    "metadata": {
      "error_type": "payment_required",
      "gateway_code": "insufficient_credits"
    }
  }
}

{
  "error": {
    "code": 404,
    "message": "The requested model does not exist or is not granted to this key. GET /api/v1/models lists the model aliases available to this key.",
    "metadata": {
      "error_type": "not_found",
      "gateway_code": "model_not_found",
      "param": "model"
    }
  }
}

Authorization

An inference key, as Authorization: Bearer KEY.

Keys and limits

Body application/json

modelstringrequired
A text-to-speech model from GET /api/v1/models?output_modalities=speech, such as hexgrad/kokoro-82m.
inputstringrequired
1 to 4,096 characters. An array of turns (several speakers) is a 400.
voicestring
One of the model's supported_voices; omitted, its default_voice.
response_formatstring
pcm (the default: signed 16-bit little-endian mono) or mp3.

pcmmp3
speednumber
0.25 to 4.0, on a model whose speech_speed is true.
providerobject
The audio routes read only the data policy fields; order, only, ignore, allow_fallbacks and sort are accepted and ignored. With the OpenAI SDK, send it in extra_body.
Show 2 child fields
- zdrboolean
  true keeps the request on providers that declare 0 days of retention.
- data_collectionstring
  deny keeps the request on providers that declare no training and 0 days of retention.
  
  allowdeny

Response 200

The audio: audio/mpeg, or audio/pcm at the provider's rate, with Cache-Control: no-store and the X-Generation-Id header.

Errors

400
A field is missing or malformed (invalid_request, with metadata.param), or the model cannot do what the request asks (unsupported_capability).
401
No key, or the key is unknown, expired, revoked or disabled.
402
Your balance is spent and the model is not free, or the request could cost more than your balance.
404
No model has this name, or your key may not call it.

Every error code