> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Voice llms.txt

> Machine-readable documentation index for the Voice section — guide pages and API endpoints for AI agents and LLMs

# Telnyx Voice — Documentation Index

> Voice API, speech-to-text, text-to-speech, and voice design. One section of the Telnyx developer docs ([https://developers.telnyx.com](https://developers.telnyx.com)).
> Root index: [https://developers.telnyx.com/llms.txt](https://developers.telnyx.com/llms.txt) · Full content for this section: [https://developers.telnyx.com/development/llms/voice-llms-full-txt.md](https://developers.telnyx.com/development/llms/voice-llms-full-txt.md)

## Subsections

Focused per-subsection files (index + full content):

* [Overview](https://developers.telnyx.com/development/llms/voice-overview-llms-txt.md) ([full](https://developers.telnyx.com/development/llms/voice-overview-llms-full-txt.md))
* [STT](https://developers.telnyx.com/development/llms/voice-stt-llms-txt.md) ([full](https://developers.telnyx.com/development/llms/voice-stt-llms-full-txt.md))
* [TTS](https://developers.telnyx.com/development/llms/voice-tts-llms-txt.md) ([full](https://developers.telnyx.com/development/llms/voice-tts-llms-full-txt.md))
* [Voice Design](https://developers.telnyx.com/development/llms/voice-voice-design-llms-txt.md) ([full](https://developers.telnyx.com/development/llms/voice-voice-design-llms-full-txt.md))

## Overview

* [Overview](https://developers.telnyx.com/docs/voice/overview.md): Overview of Telnyx Voice — standalone components for building voice AI applications, including STT, TTS, programmable voice, WebRTC, and SIP trunking.

## STT

* [Overview](https://developers.telnyx.com/docs/voice/stt/overview.md): Real-time and batch audio transcription via WebSocket, REST, or in-call.
* [Quickstart](https://developers.telnyx.com/docs/voice/stt/getting-started.md): Stream audio to Telnyx Speech-to-Text and see live transcripts in under 5 minutes with this end-to-end Python and JavaScript quickstart.
* [Models](https://developers.telnyx.com/docs/voice/stt/models.md): Compare Telnyx Speech-to-Text engines and models — Deepgram, Whisper, Google, Azure, xAI, AssemblyAI, Speechmatics, Soniox, Parakeet — by accuracy, latency, language coverage, and price.
* [Migration](https://developers.telnyx.com/docs/voice/stt/migration.md): Migrate from Deepgram, AssemblyAI, Google, or other speech-to-text providers to Telnyx STT in minutes by changing only two to three lines of code.
* [Lifecycle](https://developers.telnyx.com/docs/voice/stt/websocket-streaming.md): How the Telnyx Speech-to-Text WebSocket endpoint works for real-time streaming, including connection, audio frames, transcript messages, and shutdown.
* [Overview](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters.md): Reference for query parameters on the Telnyx Speech-to-Text WebSocket endpoint, including engine, model, language, and redaction options.
* [Audio Formats](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/audio-formats.md): Supported audio input formats, sample rates, and engine compatibility for the Telnyx Speech-to-Text WebSocket streaming endpoint and binary frames.
* [Engines & Models](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/engines-and-models.md): Available speech-to-text engines and models on Telnyx — Deepgram, Telnyx native, Google, Azure, xAI, AssemblyAI, Speechmatics, Soniox, Parakeet — selectable via query parameters.
* [End-of-Turn Detection](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/end-of-turn.md): Flux end-of-turn detection parameters for voice agent turn-taking.
* [Language](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/language.md): Configure the language for Telnyx Speech-to-Text WebSocket streaming using BCP-47 codes, with per-engine differences in supported languages and behavior.
* [Interim Results](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/interim-results.md): Enable interim results to receive partial transcripts as audio streams to the Telnyx Speech-to-Text WebSocket endpoint (Deepgram engine only).
* [Endpointing](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/endpointing.md): Configure silence-based endpointing for utterance boundary detection on the Telnyx Speech-to-Text WebSocket endpoint (Deepgram, xAI, Google, Speechmatics, and Soniox).
* [Keyword Boosting](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/keyword-boosting.md): Boost recognition of specific terms (keyterm and keywords parameters).
* [Redaction](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/parameters/redaction.md): Automatically redact PII such as numbers, names, and SSNs from Telnyx streaming transcription results using Deepgram redaction parameters.
* [Messages](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/responses.md): Reference for binary audio frames and JSON message types exchanged over the Telnyx Speech-to-Text WebSocket connection in both directions.
* [Errors](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/errors.md): Error codes and troubleshooting tips for the Telnyx Speech-to-Text WebSocket endpoint, including invalid parameters, engine mismatches, and disconnects.
* [Examples](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/examples.md): Complete Python and JavaScript code examples for streaming audio to the Telnyx Speech-to-Text WebSocket API and printing live transcription results.
* [Production Patterns](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/production-patterns.md): Reconnect, backoff, partial handling, buffering, and monitoring patterns for WebSocket STT.
* [Pricing](https://developers.telnyx.com/docs/voice/stt/websocket-streaming/pricing.md): Pricing for Telnyx Speech-to-Text WebSocket streaming. Billed per minute of audio streamed in real time, with model-tier rates and volume discounts.
* [Overview](https://developers.telnyx.com/docs/voice/stt/rest-api.md): Transcribe audio files synchronously with the Telnyx Speech-to-Text REST API by uploading a file or providing a public URL and receiving text.
* [Overview](https://developers.telnyx.com/docs/voice/stt/rest-api/parameters.md): Reference of all parameters for the Telnyx Speech-to-Text REST API — audio source, language, model, diarization, punctuation, and response options.
* [Models](https://developers.telnyx.com/docs/voice/stt/rest-api/parameters/models.md): Available speech-to-text models on the Telnyx STT REST API. Compare general, telephony, and specialty models by language, accuracy, and latency.
* [Audio Formats](https://developers.telnyx.com/docs/voice/stt/rest-api/parameters/audio-formats.md): Supported audio formats for the Telnyx Speech-to-Text REST API — WAV, MP3, FLAC, OGG, and more. Includes recommended sample rates and encodings.
* [Model Config](https://developers.telnyx.com/docs/voice/stt/rest-api/parameters/model-config.md): Model configuration options for the Telnyx Speech-to-Text REST API — biasing, hotwords, language hints, and per-request tuning of transcription accuracy.
* [Response Format](https://developers.telnyx.com/docs/voice/stt/rest-api/parameters/response.md): Response format reference for the Telnyx Speech-to-Text REST API — transcript text, words, timestamps, confidence, and per-channel diarization fields.
* [Pricing](https://developers.telnyx.com/docs/voice/stt/rest-api/pricing.md): Pricing for the Telnyx Speech-to-Text REST API. Billed per minute of audio processed, with model-tier rates and volume discounts available on request.
* [In-Call Transcription](https://developers.telnyx.com/docs/voice/stt/in-call-transcription.md): Real-time speech-to-text during live Telnyx voice calls via Voice API or TeXML.

## TTS

* [Overview](https://developers.telnyx.com/docs/voice/tts/overview.md): Synthesize natural speech from text via WebSocket streaming, REST API, or in-call playback.
* [Lifecycle](https://developers.telnyx.com/docs/voice/tts/websocket-streaming.md): How the Telnyx Text-to-Speech WebSocket endpoint works for real-time streaming, including connection, text messages, audio frames, and shutdown signals.
* [Configuration](https://developers.telnyx.com/docs/voice/tts/websocket-streaming/configuration.md): Configuration surfaces for Telnyx Text-to-Speech WebSocket streaming, including connection-time query parameters and per-message voice settings.
* [Messages](https://developers.telnyx.com/docs/voice/tts/websocket-streaming/messages.md): Reference for WebSocket frame types — client-to-server text messages and server-to-client audio frames — used in the Telnyx Text-to-Speech streaming API.
* [Errors](https://developers.telnyx.com/docs/voice/tts/websocket-streaming/errors.md): WebSocket TTS error codes and troubleshooting tips for handshake failures, authentication issues, and runtime streaming errors on the Telnyx platform.
* [Examples](https://developers.telnyx.com/docs/voice/tts/websocket-streaming/examples.md): Working Python and JavaScript code samples showing how to stream text-to-speech audio over the Telnyx WebSocket TTS endpoint with basic and advanced setups.
* [Overview](https://developers.telnyx.com/docs/voice/tts/rest-api.md): Single-request text-to-speech with HTTP chunked streaming — start playing before synthesis finishes.
* [Request](https://developers.telnyx.com/docs/voice/tts/rest-api/request.md): REST TTS request body fields — text, voice, output type, and provider-specific settings.
* [Response](https://developers.telnyx.com/docs/voice/tts/rest-api/response.md): REST TTS response formats — streaming audio, base64, and async retrieval.
* [Examples](https://developers.telnyx.com/docs/voice/tts/rest-api/examples.md): Code examples for the Telnyx Text-to-Speech REST API showing OpenAI SDK compatibility, synchronous and streaming playback, and async retrieval.
* [API Reference](https://developers.telnyx.com/docs/voice/tts/rest-api/api-reference.md): OpenAPI reference for the Telnyx Text-to-Speech REST endpoints, including the generate speech endpoint and request/response schemas for all parameters.
* [Overview](https://developers.telnyx.com/docs/voice/tts/providers/telnyx.md): Overview of Telnyx native text-to-speech models, comparing latency, quality, language coverage, and expressive control for the TTS REST API.
* [Natural](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/natural.md): Telnyx Natural is a low-latency English text-to-speech model backed by Rime Mist, designed for real-time voice agents and conversational applications.
* [NaturalHD](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/naturalhd.md): Telnyx NaturalHD is a high-fidelity multilingual text-to-speech model backed by Rime Arcana, offering studio-quality voices for premium voice applications.
* [KokoroTTS](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/kokoro.md): Telnyx KokoroTTS is a lightweight, lowest-latency text-to-speech model ideal for real-time voice agents and interactive applications on the Telnyx TTS API.
* [Qwen3TTS](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/qwen3.md): Telnyx Qwen3TTS provides high-quality voice cloning with native support for 11 languages, ideal for multilingual voice agents on the Telnyx TTS API.
* [Ultra](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/ultra.md): Telnyx Ultra text-to-speech delivers sub-100ms latency across 44 languages, available exclusively through the TTS REST API for ultra-fast voice synthesis.
* [Grok](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/grok.md): xAI Grok voices for expressive, multilingual text-to-speech in Telnyx Voice AI Assistants.
* [Bayan](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/bayan.md): Telnyx Bayan is an Arabic text-to-speech model covering 13 dialects plus English, ideal for Arabic-language voice agents on the Telnyx TTS API.
* [Sukhan](https://developers.telnyx.com/docs/voice/tts/providers/telnyx/sukhan.md): Telnyx Sukhan is an Urdu text-to-speech model with a curated set of 14 voices, ideal for Urdu-language voice agents on the Telnyx TTS API.
* [Rime](https://developers.telnyx.com/docs/voice/tts/providers/rime.md): Configure Rime as a text-to-speech provider on Telnyx with Coda and ArcanaV3 models, voice format strings, speed control, and language coverage.
* [Minimax](https://developers.telnyx.com/docs/voice/tts/providers/minimax.md): Configure Minimax as a text-to-speech provider on Telnyx with expressive voices and fine-grained speed, volume, and pitch controls per request.
* [Resemble](https://developers.telnyx.com/docs/voice/tts/providers/resemble.md): Configure Resemble AI as a text-to-speech provider on Telnyx using your own Resemble API key, with voice cloning and custom voice support.
* [Inworld](https://developers.telnyx.com/docs/voice/tts/providers/inworld.md): Configure Inworld as a text-to-speech provider on Telnyx with Mini low-latency, Max high-quality, and TTS-2 latest-generation models, voice format strings, and language support.
* [xAI](https://developers.telnyx.com/docs/voice/tts/providers/xai.md): xAI Grok TTS provider — expressive multilingual voices with speech tags and auto language detection.
* [Fish Audio](https://developers.telnyx.com/docs/voice/tts/providers/fishaudio.md): Configure Fish Audio as a text-to-speech provider on Telnyx with curated voices, cross-lingual synthesis, and multiple audio formats and sample rates.
* [AWS Polly](https://developers.telnyx.com/docs/voice/tts/providers/aws.md): Configure AWS Polly as a text-to-speech provider on Telnyx, with neural, generative, and long-form synthesis engines and voice format strings.
* [SSML Tags](https://developers.telnyx.com/docs/voice/tts/providers/aws/ssml-tags.md): Programmable voice with SSML tags from Telnyx - perfect for your
* [Azure](https://developers.telnyx.com/docs/voice/tts/providers/azure.md): Configure Microsoft Azure Speech as a text-to-speech provider on Telnyx, with multilingual neural voices, voice format strings, and SSML support.
* [ElevenLabs](https://developers.telnyx.com/docs/voice/tts/providers/elevenlabs.md): Configure ElevenLabs as a text-to-speech provider on Telnyx using your own ElevenLabs API key, with voice cloning and premium voice selection.
* [Pronunciation Dictionaries](https://developers.telnyx.com/docs/voice/tts/pronunciation-dictionaries.md): Control how specific words are spoken during TTS synthesis with custom pronunciation dictionaries.
* [In-Call Playback](https://developers.telnyx.com/docs/voice/tts/in-call-playback.md): Play Telnyx text-to-speech audio during live voice calls using the Programmable Voice API or TeXML, with options for streaming and per-call voice selection.
* [Pricing](https://developers.telnyx.com/docs/voice/tts/rest-api/pricing.md): Pricing for the Telnyx Text-to-Speech REST API, including per-character rates by engine, voice tier, and supported provider model.

## Voice Design

* [Overview](https://developers.telnyx.com/docs/voice/voice-design-lab.md): Create custom voices from text descriptions or audio recordings, then use them across all Telnyx voice products.
* [Overview](https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/concepts.md): Use AI to generate voices from natural language descriptions — understand the concepts, then create one via the portal or API.
* [Quickstart](https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/quickstart.md): Create a custom synthetic voice step-by-step using the Telnyx Voice Design portal or API, including prompts, reference audio, and provider selection.
* [Parameters](https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/api-details.md): Provider differences and generation parameters for the Voice Design API.
* [Prompting Guide](https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/prompting-guide.md): Write voice descriptions that produce consistent, high-quality results — format templates, dimension guides, and common pitfalls.
* [Overview](https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/concepts.md): Clone a voice from a short audio recording — capture a speaker's identity from a sample.
* [Quickstart](https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/quickstart.md): Clone a voice step-by-step — upload a file, record in the browser, or use the API.
* [Parameters](https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/parameters.md): Models, audio requirements, and async flows for the Voice Clone API.
* [Responses](https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/responses.md): Reference for the Voice Clone API response, including the voice ID format, status fields, sample audio URLs, and timestamps returned for each clone.
* [Errors](https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/errors.md): Reference for error codes returned by the Telnyx Voice Clone API, including general errors and provider-specific failures with troubleshooting tips.
* [Using Custom Voices](https://developers.telnyx.com/docs/voice/voice-design-lab/using-custom-voices.md): Use your custom voice clones across AI Assistants, Call Control, and the TTS API.

## API Reference (Voice)

### Audio

* [Transcribe speech to text](https://developers.telnyx.com/api-reference/audio/transcribe-speech-to-text.md): Transcribe speech to text. This endpoint is consistent with the OpenAI Transcription API and may be used with the OpenAI JS or Python SDK.

### Text To Speech Commands

* [List available voices](https://developers.telnyx.com/api-reference/text-to-speech-commands/list-available-voices.md): Retrieve a list of available voices from one or all TTS providers. When `provider` is specified, returns voices for that provider only. Otherwise, returns voic…

### Voice Designs

* [List voice designs](https://developers.telnyx.com/api-reference/voice-designs/list-voice-designs.md): Returns a paginated list of voice designs belonging to the authenticated account.
* [Create or add a version to a voice design](https://developers.telnyx.com/api-reference/voice-designs/create-or-add-a-version-to-a-voice-design.md): Creates a new voice design (version 1) when `voice_design_id` is omitted. When `voice_design_id` is provided, adds a new version to the existing design instead…
* [Get a voice design](https://developers.telnyx.com/api-reference/voice-designs/get-a-voice-design.md): Returns the latest version of a voice design, or a specific version when `?version=N` is provided. The `id` parameter accepts either a UUID or the design name.
* [Rename a voice design](https://developers.telnyx.com/api-reference/voice-designs/rename-a-voice-design.md): Updates the name of a voice design. All versions retain their other properties.
* [Delete a voice design](https://developers.telnyx.com/api-reference/voice-designs/delete-a-voice-design.md): Permanently deletes a voice design and all of its versions. This action cannot be undone.
* [Download voice design audio sample](https://developers.telnyx.com/api-reference/voice-designs/download-voice-design-audio-sample.md): Downloads the WAV audio sample for the voice design. Returns the latest version's sample by default, or a specific version when `?version=N` is provided. The \`…
* [Delete a specific version of a voice design](https://developers.telnyx.com/api-reference/voice-designs/delete-a-specific-version-of-a-voice-design.md): Permanently deletes a specific version of a voice design. The version number must be a positive integer.

### Voice Clones

* [List voice clones](https://developers.telnyx.com/api-reference/voice-clones/list-voice-clones.md): Returns a paginated list of voice clones belonging to the authenticated account.
* [Create a voice clone from a voice design](https://developers.telnyx.com/api-reference/voice-clones/create-a-voice-clone-from-a-voice-design.md): Creates a new voice clone by capturing the voice identity of an existing voice design. The clone can then be used for text-to-speech synthesis.
* [Create a voice clone from an audio file upload](https://developers.telnyx.com/api-reference/voice-clones/create-a-voice-clone-from-an-audio-file-upload.md): Creates a new voice clone by uploading an audio file directly. Supported formats: WAV, MP3, FLAC, OGG, M4A. For best results, provide 5–10 seconds of clear spe…
* [Update a voice clone](https://developers.telnyx.com/api-reference/voice-clones/update-a-voice-clone.md): Updates the name, language, or gender of a voice clone.
* [Delete a voice clone](https://developers.telnyx.com/api-reference/voice-clones/delete-a-voice-clone.md): Permanently deletes a voice clone. This action cannot be undone.
* [Download voice clone audio sample](https://developers.telnyx.com/api-reference/voice-clones/download-voice-clone-audio-sample.md): Downloads the WAV audio sample that was used to create the voice clone.