Fish Audio TTS provider

Configure Fish Audio as a text-to-speech provider on Telnyx with curated voices, cross-lingual synthesis, and multiple audio formats and sample rates.

Voice format: FishAudio.<Model>.<VoiceId>

Fish Audio is a Telnyx-hosted external TTS provider. Telnyx exposes a hand-vetted shortlist of Fish Audio voices from their public Voice Library.

Fish Audio is cross-lingual — any voice can speak any language from the input text. The language field in the voice listing is the voice’s native accent only, not a synthesis constraint.

Models

Model	Description
s2.1-pro	Latest generation. Improved quality, latency, and throughput. Default.
s2-pro	Previous generation. Multi-speaker, expression control.
s1	Oldest generation.

All curated voices are available under all three models.

Curated Voices

Voice	Gender	Native Language	Voice ID	Sample
Aria	Female	English	933563129e564b19a115bedd57b7406a
Nova	Female	English	b545c585f631496c914815291da4e893
Paula	Female	English	c2623f0c075b4492ac367989aee1576f
Claire	Female	French	5567200c7d8341738f0892bbacd3be3c
Yuki	Female	Japanese	5161d41404314212af1254556477c17d
Ethan	Male	English	536d3a5e000945adb7038665781a4aca
Atlas	Male	English	c5f56a6cc2ec4fa8920cb4c5889a3fb7
Max	Male	English	802e3bc2b27e49c2995d23ef70e6ac89
Adrian	Male	English	bf322df2096a46f18c579d0baa36f41d
Mateo	Male	Spanish	35199d5438854f5d9157c500479ab684

Only curated catalog voices are accepted for synthesis. Arbitrary Fish Voice-Library reference_ids cannot be used under the Telnyx API key.

Emotion Tags

Fish Audio S2 models (s2.1-pro, s2-pro) support inline emotion, tone, and audio-effect markers placed directly in the input text. S1 uses parentheses — (happy) — instead of brackets. The markers are processed by the upstream Fish Audio API and do not add latency or count toward token limits.

[happy] What a beautiful day!
[sad] I'm sorry to hear that.
[excited] This is amazing news!
[whispering] I have a secret to share.
[laughing] That was hilarious! Ha, ha!

The same syntax works on both the REST endpoint and the WebSocket text field. Markers can be combined for layered effects — [excited][laughing] We won! Ha ha! — and accept intensity modifiers like [slightly sad], [very excited], [extremely angry].

For the full list of supported emotions, tone markers, audio effects, and S1 syntax, see Fish Audio’s Emotion Control guide.

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WebSocket

Query Parameters

Parameter	Type	Default	Description
audio_format	string	linear16	mp3, wav, linear16 (maps to PCM).
sample_rate	integer	24000	Depends on format (see table below).

Voice Settings

Fish Audio does not expose speed or pitch controls. voice_settings are limited to format and sample rate overrides. Emotion and tone are controlled inline in the text via bracket markers — see Emotion Tags below.

Field	Type	Default	Description
format	string	pcm	mp3, wav, pcm, opus.
sample_rate	integer	24000	Sample rate in Hz (valid values depend on format).

{
  "text": " ",
  "voice_settings": {
    "format": "mp3",
    "sample_rate": 44100
  }
}

REST API

Fields

Field	Type	Default	Description
format	string	pcm	mp3, wav, pcm, opus.
sample_rate	integer	24000	Sample rate in Hz (valid values depend on format).
output_type	string	binary_output	binary_output, base64_output, or audio_id.

Response

Default (binary_output): chunked audio bytes.

With output_type: "base64_output": JSON with base64-encoded audio.

With output_type: "audio_id": JSON with an audio_url for deferred retrieval.

Audio Formats & Sample Rates

Each format has a fixed set of accepted sample rates:

Format	Accepted Sample Rates (Hz)
pcm	8000, 16000, 24000, 32000, 44100
wav	8000, 16000, 24000, 32000, 44100
mp3	32000, 44100
opus	48000

On WebSocket, the audio_format query parameter and voice_settings.format are independent parameters with different vocabularies. The audio_format query param accepts mp3, wav, and linear16 (which maps to pcm). The voice_settings.format field accepts mp3, wav, pcm, and opus directly. If both are set, voice_settings.format takes precedence.

In-Call Playback

Fish Audio is available for in-call TTS via Call Control speak and TeXML <Say>. For telephony playback, the gateway automatically delivers MP3 at 44.1 kHz to ensure correct resampling by the call-control audio pipeline.

See In-Call Playback for details.

Provider Docs

• Fish Audio API Reference
• Fish Audio Voice Library