Text to speech

Turn text into natural speech and get back a link to the audio file. Choose the model, the output format and the speaking rate.

Use when you need spoken audio from text: a voiceover line, a narration clip, an announcement, or an audio version of something you wrote. Up to 2,000 characters per call, about two minutes of speech. The audio is returned as a link that works for 24 hours, not as inline data, so download it if you need to keep it. Billed on the UTF-8 byte length of your text, so the exact price is known before the call. To speak in a voice you cloned with voice.clone, pass its voice_id; you can only use voices your own workspace owns.

Price

$0.0450 per 1,000 UTF-8 bytes of text. An exact rate, not an estimate. The total is that rate times the UTF-8 bytes of text in your request, so you can work out what a call costs before you make it. No call costs less than

0.0020 or more than

0.36, the price of the largest request this endpoint takes, 8,000 UTF-8 bytes of text. discover and inspect quote your exact request before it runs.

Input

Field	Type	Required	Notes
`text`	`string`	yes	The text to speak. Billed on its UTF-8 byte length, so non-Latin scripts cost more per character than English does.
`model`	`s2.1-pro`, `s2-pro`, `s1`		Which voice model to use. All three cost the same. Defaults to `"s2.1-pro"`.
`format`	`mp3`, `opus`		Audio format of the file you get back. Uncompressed formats are not offered. Defaults to `"mp3"`.
`prosody`	`object`		Delivery adjustments.
`prosody.speed`	`number`		Speaking rate. 1 is normal, 0.5 is half speed, 2 is double. Defaults to `1`.
`prosody.volume`	`number`		Loudness adjustment in dB. Defaults to `0`.
`voice_id`	`string`		Speak in one of your own cloned voices, as returned by voice.clone or voice.list. Leave it out to use the stock voice. A voice_id belonging to another workspace is refused exactly as an unknown one is.
`normalize`	`boolean`		Expand numbers, dates and abbreviations before speaking them. Leave on unless you have already written the text exactly as it should sound. Defaults to `true`.
`mp3_bitrate`	`64`, `128`, `192`		MP3 quality in kbps. Ignored for opus. Defaults to `128`.

These are all the fields this endpoint accepts. Anything else is rejected as a validation_error rather than forwarded to the provider.

Example

curl -X POST https://api.usegoro.ai/v1/run \
  -H "Authorization: Bearer $GORO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"slug":"voice.speak","input":{"text":"Your order has shipped and should arrive on Thursday."}}'

Response

One row of the response. Values are illustrative.

{
  "bytes": 73977,
  "model": "s2.1-pro",
  "format": "mp3",
  "audio_url": "https://storage.example.com/voice-output/workspace/run.mp3?token=signed-and-expiring",
  "expires_at": "2026-01-02T09:30:00.000Z",
  "utf8_bytes": 50,
  "content_type": "audio/mpeg"
}

Guide

CLI reference

API reference

Tools

Text to speech

Price

Input

Example

Response

​Price

​Input

​Example

​Response

Price

Input

Example

Response