Kos is a free Polish voice assistant running on ZeroGPU: Silero VAD β Whisper large-v3 β PLLuM-12B (EXL3) β TTS. It's a cascade, not a native speech-to-speech model.
The interesting part is what happens between "the model wrote a sentence" and "the sentence is spoken":
β’ math, units, exchange rates (NBP) and weather are computed by code, not by the LLM
β’ facts go to Polish Wikipedia/Wikidata first, with sources you can check
β’ free-chat answers are buffered and rejected if they contain an unsourced number, a fake citation or a false "I have no internet"
β’ a rejected answer is never spoken: Kos looks it up or says it isn't sure
Voice: my own cloned voice on Cartesia. When its daily/monthly limit runs out, Kos switches automatically to Chatterbox, then Piper. It still answers, it just sounds different.
Limits: it's a 12B model, so small talk can still be wrong. Polish only. ZeroGPU quota is shared by all visitors.
Try it (allow the mic, speak Polish, headphones work best):
Mati83moni/kos-pl
If it answers something wrong, tell me in the Space's Community tab: what you said, what Kos replied. Those cases become regression tests.