Text-to-Speech - Unifically

Generate high-quality speech audio from text using ElevenLabs models — with premade voices, your own custom cloned voices, or one-off voice cloning from sample URLs.

Model

elevenlabs/text-to-speech

Parameters

Parameter	Type	Required	Default	Description
`text`	string	Yes	-	Text to convert to speech. Character limits depend on `model_id` (see models below)
`voice`	string or array	Yes	-	Voice to use — see Voice Options
`model_id`	string	No	`eleven_flash_v2_5`	TTS model (see models below)
`with_timestamps`	boolean	No	`false`	Return character/word timing data alongside the audio
`speed`	number	No	`1.0`	Speech speed. Below `1.0` slower, above `1.0` faster. Shorthand for `voice_settings.speed`
`voice_settings`	object	No	-	Fine-tune voice behavior (see below)
`output_format`	string	No	`mp3_44100_128`	Audio output format (see formats below)
`language_code`	string	No	`auto`	ISO 639-1 language code to force language (e.g. `en`, `es`)
`seed`	integer	No	-	Seed for reproducible generation (0–4294967295)

Voice Options

The voice parameter accepts two forms:

Form	Example	Meaning
Voice ID	`"voice": "21m00Tcm4TlvDq8ikWAM"`	A premade voice (from `GET /v1/resources/elevenlabs/voices`) or a custom `voice_id` you created. Both work identically.
Sample URLs	`"voice": ["https://.../a.mp3", "https://.../b.mp3"]`	One-off clone for this request only; nothing is stored. Same rules as custom-voice samples.

Custom Voices

Clone a voice from sample recordings and get back a permanent voice_id:

POST /v1/resources/elevenlabs/voices

Field	Type	Required	Description
`samples`	array of strings	Yes	URLs of audio recordings of one speaker. More recordings of the same person produce a better voice. Max 25 samples, max 25 MB each.
`name`	string	No	A label for your own reference. Not an identifier.

curl -X POST https://api.unifically.com/v1/resources/elevenlabs/voices \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "samples": [
      "https://cdn.example.com/recording1.mp3",
      "https://cdn.example.com/recording2.wav"
    ],
    "name": "Podcast Talker"
  }'

Response:

{
  "success": true,
  "data": {
    "voice_id": "NLQzxuY9B0rsgFcPKVW4",
    "name": "Podcast Talker",
    "samples": ["https://cdn.example.com/recording1.mp3", "https://cdn.example.com/recording2.wav"]
  }
}

Store the voice_id. It is returned only once — there is no endpoint that lists custom voices, by design (voice IDs are private to whoever holds them).

The voice is permanent: we keep our own copy of your samples, so it keeps working even after your original URLs go offline.
Sample URLs must be direct downloads — redirects and link shorteners are rejected.
Supported audio formats: mp3, wav, ogg, opus, m4a, flac, webm.
Voice IDs from your own ElevenLabs account cannot be used here — create the voice through this endpoint instead.

voice_settings

Field	Type	Default	Description
`stability`	number	`0.5`	0–1. Lower = more expressive/variable, higher = more monotone
`similarity_boost`	number	`0.75`	0–1. How closely the output adheres to the original voice
`style`	number	`0`	0–1. Style exaggeration. Values other than 0 may add latency
`speed`	number	`1.0`	Speech speed multiplier. Wins over top-level `speed` if both are set
`use_speaker_boost`	boolean	`true`	Boost similarity to the original speaker

Available Models

Model	Description	Languages	Char Limit
`eleven_flash_v2_5`	Default. Fastest and cheapest	32	40,000
`eleven_multilingual_v2`	Highest quality, most stable on long-form	29	10,000
`eleven_v3`	Most expressive	70+	5,000
`eleven_turbo_v2_5`	Deprecated by ElevenLabs — use `eleven_flash_v2_5` instead	32	40,000

Output Formats

Format	Description
`mp3_22050_32`	MP3 22.05kHz 32kbps
`mp3_44100_64`	MP3 44.1kHz 64kbps
`mp3_44100_96`	MP3 44.1kHz 96kbps
`mp3_44100_128`	MP3 44.1kHz 128kbps (default)
`mp3_44100_192`	MP3 44.1kHz 192kbps
`opus_48000_32`	Opus 48kHz 32kbps
`opus_48000_64`	Opus 48kHz 64kbps
`opus_48000_96`	Opus 48kHz 96kbps
`opus_48000_128`	Opus 48kHz 128kbps
`opus_48000_192`	Opus 48kHz 192kbps
`pcm_16000`	Raw PCM 16kHz
`pcm_22050`	Raw PCM 22.05kHz
`pcm_24000`	Raw PCM 24kHz
`pcm_44100`	Raw PCM 44.1kHz
`pcm_48000`	Raw PCM 48kHz
`wav_44100`	WAV 44.1kHz
`ulaw_8000`	μ-law 8kHz (Twilio)
`alaw_8000`	A-law 8kHz

Resources

Get available premade voices from the Resources API:

GET /v1/resources/elevenlabs/voices

Example — custom voice with timestamps

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "elevenlabs/text-to-speech",
    "input": {
      "text": "Hello world, this is my cloned voice.",
      "voice": "NLQzxuY9B0rsgFcPKVW4",
      "model_id": "eleven_multilingual_v2",
      "with_timestamps": true,
      "speed": 1.1
    }
  }'

Response

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "processing"
  }
}

Completed Response

Poll GET /v1/tasks/{task_id} until status is completed:

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "completed",
    "output": {
      "audio_url": "https://files.unifically.com/audio/abc123.mp3",
      "alignment": {
        "characters": ["H", "e", "l", "l", "o"],
        "character_start_times_seconds": [0.0, 0.081, 0.15, 0.21, 0.26],
        "character_end_times_seconds": [0.081, 0.15, 0.21, 0.26, 0.32]
      },
      "normalized_alignment": { "...": "same shape, for the spoken (normalized) text" },
      "words": [
        { "word": "Hello", "start": 0.0, "end": 0.32 },
        { "word": "world,", "start": 0.38, "end": 0.79 }
      ]
    }
  }
}

alignment maps your original text; normalized_alignment maps the text as spoken (numbers and abbreviations expanded).
words is derived from alignment — use it directly for captions and audio/video sync. Punctuation stays attached to its word.
Without with_timestamps, the output contains only audio_url.

​Model

​Parameters

​Voice Options

​Custom Voices

​voice_settings

​Available Models

​Output Formats

​Resources

​Example — custom voice with timestamps

​Response

​Completed Response

Model

Parameters

Voice Options

Custom Voices

voice_settings

Available Models

Output Formats

Resources

Example — custom voice with timestamps

Response

Completed Response