Hackathon · 2026 · Localhost: On-Device Agent Hackathon · London 2026
OffBabel
An offline language tutor that runs on a Reachy Mini robot. You learn by speaking Spanish or English, or by fingerspelling British Sign Language, and it all works without internet.
Cosine and ExoLabs Track Winner - On-Device Agent Hackathon
The event had no overall prize, just tracks. OffBabel won two of them, Cosine and ExoLabs.
Python · React · Local LLM · MediaPipe
The problem
Most apps and schools focus on grammar and writing, not on real conversation. When I moved to England I was fine with grammar and reading, but I still found it hard to speak fluently. That gap is what OffBabel sets out to fix.
What I built
OffBabel runs fully on a Reachy Mini robot with no internet. You can practise by speaking Spanish or English and get feedback, or by fingerspelling British Sign Language to a webcam. It also keeps track of your mistakes and brings them back later so you practise them more.
What it does
- Works Offline. The speech, the language model, and the sign reading all run on the device. Nothing is sent to the internet.
- Two Ways to Learn. Speak in Spanish or English, or fingerspell British Sign Language to a webcam.
- Reads Sign Language. It uses MediaPipe hand tracking and a KNN model to read your BSL fingerspelling as you sign.
- Remembers Mistakes. It saves the mistakes you make and brings them back later so you get more practice on the hard ones.
Photos
Gallery
The full engineering is on GitHub.