Jared Palmer Open-Sources Kev, a Family of Small Judge Models Rebuilt on Qwen3.5
Developer Jared Palmer open-sourced Kev, a family of small "Jev-style" judge models, and on 09-22 completed a rebuild on Qwen3.5, releasing 0.8B, 4B and 9B checkpoints under Apache-2.0 with training code and a frozen evaluation suite. The project reached Hacker News and offers a new lightweight, locally runnable option for judge models.
Confirmed
- The latest Kev is built on Qwen3.5 in 0.8B, 4B and 9B sizes, Apache-2.0 licensed, with training code, a frozen eval suite, and a fine-tuning script that runs on Modal.
- The 9B model fits in bf16 on a 32GB Mac.
- Earlier evolution: Kev-0.5B was based on Qwen2.5-0.5B with a TypeSafe-compatible API, trainable and runnable on a MacBook Pro; it was then upgraded to 0.6B/4B/8B on Qwen3 using LoRA plus a small pointer head, trainable on a single H100 in 40 minutes.
- Kev is positioned as a self-trainable, self-deployable small judge model for decision tasks.
Why it matters
- Large judge models typically require heavy compute; Kev shows small models can handle judging tasks fully locally, lowering the barrier to entry.
- Rapid iteration within a day (Qwen2.5 → Qwen3 → Qwen3.5) with training code open-sourced makes reproduction and secondary development easy for the community.
2026-09-21 ~ 2026-09-22 · 5 related posts
- Episode 1: Jared Palmer Open-Sources Kev, a Family of Small Judge Models Rebuilt on Qwen3.5(2026-09-21, 5 posts)
- Episode 2: Classification Model Jev Goes Viral for Fast, Cheap AI Judgments(2026-09-24, 2 posts)
- Episode 3: Jev, a judgment-only model, takes off on Vercel AI Gateway(2026-09-25, 8 posts)
- Episode 4: TypeSafe AI Launches Decision Model Jev, Wins LangChain Endorsement(2026-09-26, 5 posts)
Primary sources
- Kev open-source decision models scale to 0.6B/4B/8B, trainable in 40 min on one H100 — TheMoonMidas · 2026-09-21
- Kev: tiny Jev-like family of decision models built on Qwen3.5 hits Hacker News — petrusenko_max · 2026-09-21
- Kev-0.5B: Tiny Open-Source Jev-Like Decision Model Built on Qwen2.5-0.5B — multiply_matrix · 2026-09-21
- Kev refactored onto Qwen3.5: open-source decision models now at 0.8B, 4B and 9B — alexcovo_eth · 2026-09-22
- [source] Kev: open-source 0.8B/4B/9B judge models on Qwen3.5, the 9B fits a 32GB Mac — khiladi1729 · 2026-09-22