Kev: Tiny Jev-like family of decision models built on top of Qwen3.5(github.com)
453 points by tosh 23 days ago | 199 comments
tl;dr: Kev is an open-source family of small decision models (0.8B, 4B, 9B) built on Qwen3.5 that mimics Jev's architecture, offering yes/no, multiple-choice, and rating outputs with calibrated probabilities via a LoRA adapter and pointer head. It runs locally on CUDA, ROCm, or Apple Silicon (though slow on Macs due to missing DeltaNet kernels), is API-compatible with TypeSafe's System One SDK, and supports fine-tuning from released checkpoints. Kev-9B roughly matches Jev on accuracy but trails on calibration and knowledge-heavy tasks like MMLU-Pro (0.52 vs 0.84).
HN Discussion:
  • ↓Simpler embeddings + logistic classifier approach is sufficient for classification tasks
  • ↓Skeptical of opportunistic Jev-clones, preferring dedicated maintained projects like original Jev
  • ↓Questions architectural legitimacy since Qwen base uses different training paradigm than Jev
  • •Curious about practical use cases for these small decision models
  • ↑Excited about potential applications like game NPCs, styling enforcement, and tool-call routing proxies