Skip to main content
Telnyx supports routing TTS requests to alternative providers. Each has its own voice format, audio behavior, and voice settings.
All provider-specific settings below are sent via the voice_settings object in the initialization frame, not as query parameters. Only the connection parameters (voice, provider, model_id, voice_id, language, socket_id, disable_cache) are set on the URL.

AWS Polly

Voice format: aws.Polly.<Engine>.<VoiceId> — e.g., aws.Polly.Generative.Lucia Audio: Concatenated (full audio in a single chunk). Format controlled via output_format and sample_rate. Engines: standard, neural, generative, long-form. Engine can also be parsed from a hyphenated voice ID suffix (e.g., Lucia-longform).

Voice Settings


Azure Speech

Voice format: azure.<VoiceId> — e.g., azure.en-US-AvaMultilingualNeural Audio: Concatenated. Default: audio-24khz-160kbitrate-mono-mp3. Configurable via output_format. No model ID segment — Azure voices are flat identifiers. Default voice: en-US-AvaMultilingualNeural.

Voice Settings


ElevenLabs

Voice format: elevenlabs.<Model>.<VoiceId> — e.g., elevenlabs.v3.Adam Audio: Direct relay — frames are forwarded to ElevenLabs’ upstream WebSocket. Text is not buffered at sentence boundaries. Audio format is determined by ElevenLabs and is not configurable through Telnyx.

Voice Settings

Settings are relayed directly to the upstream API:

Minimax

Voice format: minimax.<Model>.<VoiceId> Audio: Streamed. Default: MP3 (32kHz, 128kbps). Set response_format to "pcm" for raw PCM (16kHz, mono). Supports voice cloning (scoped to your organization).

Voice Settings


MurfAI

Voice format: murfai.FALCON.<VoiceId> Audio: Default: MP3, 16kHz, mono. Configurable via format and sample_rate.

Voice Settings


Rime

Voice format: rime.Coda.<VoiceId> or rime.ArcanaV3.<VoiceId> Models: Coda (flagship, recommended) and ArcanaV3 (previous flagship). Coda offers sub-100ms latency, 184 voices, and supports English, Spanish, French, Portuguese, German, and Japanese. Audio: Default: MP3, 24kHz.

Voice Settings


Resemble

Voice format: resemble.Turbo.<VoiceId> Audio: Default: MP3, 48kHz. WAV defaults to 16kHz.

Voice Settings


Inworld

Voice format: inworld.<Model>.<VoiceId> Models: inworld-tts-1.5-mini (alias Mini, faster), inworld-tts-1.5-max (alias Max, higher quality), and inworld-tts-2 (alias TTS2, latest generation; supports the delivery_mode setting). Defaults to inworld-tts-1.5-mini if omitted. Audio: Default: MP3, 24kHz.

Voice Settings


Fish Audio

Voice format: FishAudio.<Model>.<VoiceId> Audio: Streamed. Default: raw PCM at 24 kHz. Configurable via format and sample_rate in voice settings. Telnyx exposes a hand-vetted shortlist of Fish Audio voices. Only curated catalog voices are accepted for synthesis. Fish Audio is cross-lingual — any voice speaks any language from the input text.

Voice Settings

No speed or pitch controls. Emotion and tone are controlled inline in the text via bracket markers on S2 models — see the Fish Audio provider page for syntax and examples.