Cactus Hybrid - On-device models that know when they're wrong
Show HN: Cactus Hybrid: We taught Gemma 4 to know when it's wrong
Cactus Hybrid introduces a breakthrough in on-device AI by post-training models like Gemma 4 E2B to self-assess their accuracy. Every generated answer includes a structured confidence score, enabling intelligent routing to cloud models only when necessary. This approach balances speed and privacy with high reliability, matching larger models like Gemini 3.1 Flash-Lite while processing most queries locally. With seamless integration for Cactus, Transformers, llama.cpp, and MLX, developers can easily implement confidence-aware AI that dynamically decides when to hand off complex tasks.
The probe was trained on zero audio data, yet achieves high accuracy on audio benchmarks, proving it reads a modality-independent correctness signal from the hidden state rather than memorizing patterns.