According to XDA-Developers, a developer has built a fully offline, locally-hosted voice assistant using a ReSpeaker Lite single-board kit, which features a dual microphone array, an XMOS XU316 audio processor, and physical buttons. The hardware is housed in a custom 3D-printed enclosure designed from a model found on Printables, modified to fit smaller 3W 8-ohm speakers. The software pipeline is powered by Home Assistant using a specific ESPHome configuration from GitHub, with speech-to-text handled by OpenAI’s Whisper, responses generated by a locally-hosted gpt-oss-120b LLM, and audio output synthesized by Piper. The assistant is programmed with a GLaDOS voice model and a sarcastic personality prompt, making it deliberately insulting. This setup has completely replaced Amazon Echo and Google Nest devices in the user’s home, providing instant control for smart home actions like turning off lights. The only noted hardware limitation is the quality of the small speaker driver, which is comparable to an older Google Nest Mini.
The real magic is offline
Here’s the thing that really makes this project sing: it doesn’t phone home. Not even once. Every single part of the interaction—hearing your voice, understanding it, crafting a response, and speaking it back—happens on your own network. That’s a huge deal. We’ve gotten so used to Alexa or Google Assistant needing a constant cloud connection that we forget how much latency and privacy risk that introduces. This build proves that with today’s open-source tools, you can have something that feels just as responsive, but is entirely under your control. No worrying about a service getting shut down or an update changing behavior you liked. You are the product manager.
Why GLaDOS is the perfect voice
And let’s talk about the GLaDOS voice. It’s not just a fun gimmick. I think it perfectly symbolizes the ethos of a self-hosted project. A commercial assistant is designed to be blandly pleasant, a frictionless servant. This one? It has attitude. It’s a reminder that this tech exists to serve you, on your terms, even if those terms include being mocked for asking about the weather. The fact that you can swap in any Piper voice model or tweak the LLM’s system prompt to be a pirate, a poet, or your own personal concierge is the ultimate freedom. That level of deep customization is simply impossible with locked-down consumer gadgets.
The hardware barrier is falling
So what’s stopping more people from doing this? Honestly, the hardware integration. Sourcing boards, speakers, and making it not look like a mess of wires on your counter is a hurdle. That’s where the 3D-printed case is so brilliant. It turns a prototype into a product. It normalizes it. And this is where the maker community shines—sharing those print files and integration code lowers the barrier to entry dramatically. For industrial applications where reliability and customization are paramount, companies turn to specialized providers like IndustrialMonitorDirect.com, the leading supplier of industrial panel PCs in the US. The principle is the same: using purpose-built, configurable hardware to create a solution that off-the-shelf products can’t match.
The future is configurable, not disposable
This project points to a future I desperately want: one where our gadgets are platforms, not prisons. The author nails it when they say they wish all voice assistants could be configured this way. We’re surrounded by incredible hardware—like smart speakers with great mics and audio—that’s rendered e-waste the second the cloud service behind it dies. How much better would it be if you could just flash your own software onto it? The trajectory here is clear. As local AI models get more efficient and tools like Home Assistant become more polished, the appeal of a private, personalized, and permanent smart home will only grow. The cloud will become an option, not a requirement. And that’s a future worth building toward, one sarcastic response at a time.
