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Home Assistant Voice Integration

Give Home Assistant's Assist voice pipeline speech-to-text and text-to-speech backed by Amazon Transcribe and Amazon Polly, through stdapi.ai's OpenAI-compatible audio routes.

About Home Assistant Assist and Wyoming

🔗 Links: Home Assistant Assist | wyoming-openai | Wyoming protocol

Home Assistant's Assist voice pipeline speaks Wyoming, a lightweight protocol for local voice satellites and speech services—not the OpenAI or Anthropic APIs directly. wyoming-openai is an open-source proxy that bridges Wyoming to any OpenAI-compatible speech-to-text and text-to-speech backend, which is what lets Assist reach stdapi.ai.

What the proxy adds on top of the audio routes:

  • Wyoming discovery - Advertises configured speech-to-text models and text-to-speech voices to Assist
  • Streaming synthesis - Speaks a response as it is generated, in overlapping chunks, rather than waiting for the whole sentence
  • Format translation - Reassembles the response as raw PCM frames for Assist's audio pipeline

Why Home Assistant + stdapi.ai?

  • No Cloud Voice Subscription
    Replace a cloud speech-to-text/text-to-speech subscription with Amazon Transcribe and Amazon Polly, billed at Bedrock/AWS rates.

  • Voice Data Stays in Your AWS Account
    Spoken audio and transcripts are processed in your account and never shared with a third-party voice assistant vendor.

  • Works with Your Existing Assist Setup
    Assist's speech-to-text and text-to-speech pipeline selection is unchanged—only the backend the proxy talks to is stdapi.ai.

  • Pay-Per-Use Pricing
    No per-satellite or per-minute voice assistant fees. Pay only Amazon Transcribe and Amazon Polly rates for actual usage.

%%{init: {'flowchart': {'htmlLabels': true}} }%%
flowchart LR
  ha["Home Assistant\nAssist"] -->|Wyoming| proxy["wyoming-openai"]
  proxy -->|OpenAI API| stdapi["<img src='../styles/logo.svg' style='height:64px;width:auto;vertical-align:middle;' /> stdapi.ai"]
  stdapi --> transcribe["<img src='../styles/logo_amazon_transcribe.svg' style='height:64px;width:auto;vertical-align:middle;' /> Amazon Transcribe"]
  stdapi --> polly["<img src='../styles/logo_amazon_polly.svg' style='height:64px;width:auto;vertical-align:middle;' /> Amazon Polly"]

Prerequisites

What You'll Need

  • ✓ stdapi.ai deployed - See deployment guide or run locally with Docker
  • ✓ Your stdapi.ai URL - reachable from wherever the proxy runs, e.g. https://api.example.com
  • ✓ Your API key - From Terraform output or configuration
  • ✓ Home Assistant - With the Assist voice pipeline set up
  • ✓ A place to run wyoming-openai - A container alongside Home Assistant, e.g. as a Home Assistant OS add-on or a standalone container

Configuration

wyoming-openai is configured through environment variables, split into a speech-to-text half and a text-to-speech half. Point both at your stdapi.ai deployment.

Environment Variables

# Speech to text
STT_OPENAI_URL=https://YOUR_STDAPI_URL/v1
STT_OPENAI_KEY=YOUR_STDAPI_KEY
STT_MODELS=amazon.transcribe

# Text to speech
TTS_OPENAI_URL=https://YOUR_STDAPI_URL/v1
TTS_OPENAI_KEY=YOUR_STDAPI_KEY
TTS_MODELS=amazon.polly-neural
TTS_VOICES=alloy

# Backend selection
STT_BACKEND=OPENAI
TTS_BACKEND=OPENAI

The proxy calls POST /v1/audio/transcriptions (see Audio Transcriptions API) for speech to text and POST /v1/audio/speech (see Audio Speech API) for text to speech, so STT_MODELS must be a speech-to-text-capable model and TTS_MODELS a text-to-speech-capable model from the correct family.

Pin the backend

Left unset, wyoming-openai probes a few well-known self-hosted backends before falling back to a generic OpenAI-compatible one. Setting STT_BACKEND=OPENAI and TTS_BACKEND=OPENAI skips that probing and connects directly.

Streaming Text to Speech

Enables: speaking a response as it is generated, instead of waiting for the whole sentence to synthesize.

Environment Variables

TTS_STREAMING_MODELS=amazon.polly-neural

Naming the same model in both TTS_MODELS and TTS_STREAMING_MODELS puts its voice in the proxy's streaming program, so Assist can use it for both a plain synthesis request and a streamed one. The proxy splits a streamed reply into sentences and synthesizes several /v1/audio/speech calls concurrently, then replays the audio in the original order.

Voice Mapping

TTS_VOICES lists OpenAI-style voice names (alloy, echo, fable, and so on); stdapi.ai maps each one to an Amazon Polly voice of matching gender and language. List one entry per voice you want Assist to offer.

Known Issues

The proxy speaks the Wyoming protocol over its own TCP port, not HTTP—there is no /health endpoint to check readiness with a plain web request. Wait for a successful Wyoming describe exchange (or check the container logs) rather than polling an HTTP path.

Next Steps