Organization repository on GitHub
A local, API-compatible replacement for Jev, TypeSafe's System One model
- GitHub stars
- 39
- Forks
- 2
- Primary language
- Python
- License
- mit
- Last pushed
- Updated Sep 2026
Repo stats from the GitHub API, cached Sep 2026.
CommunityModels & Reimplementations
Lichen
A local /v1/systemone server that reads label probabilities from a GGUF chat model, with prompt repetition and a confidence shrink toward uniform.
- Category
- Models & Reimplementations
- Format
- —
- Published by
- Community
- Author
- Mushroom-Systems
- Added
- 2026-09-28
- Last verified
- 2026-09-28
Highlights
- On 231 public JevBench v1.4 items, gemma-4-26B-A4B with the default options scored 207 correct against 200 for Jev 1.13.
- The same table lists median latency of 93 ms on one laptop GPU, against 665 ms for hosted Jev including the network.
- The README says the two systems disagree on 13 items and the edge is not significant (p = 0.09).
- A choice takes 2 to 62 options. Questions in one request are answered one after another.
- The server does not check API keys and is meant for a trusted network.
Quickstart
bash
docker run --rm --gpus all -p 8765:8765 -v "$PWD/models:/models:ro" \
lichen --model /models/gemma-4-26B_q4_0-it.ggufWatch out
MIT. Needs Docker and an NVIDIA GPU for the published setup. Models keep their own licenses. Jev's score confidence formula is unpublished, so Lichen reuses the choice formula.
Reactions & coverage
Posts, threads, and videos about this entry from around the web.
Hacker News: Jev implemented in 25 lines of Python
bashbjorn400 points · 128 commentsJev in 25 Lines of PythonRead the thread on Hacker NewsHacker News: Kev: a tiny Jev-like family built on Qwen3.5
tosh458 points · 199 commentsKev: Tiny Jev-like family of decision models built on top of Qwen3.5Read the thread on Hacker NewsHacker News: Show HN: OpenDecision, a local decision model with a Doom demo.
dwa35926 pointsShow HN: OpenDecision – a 400M zero-shot model makes local decisions, plays DoomRead the thread on Hacker NewsX: deepseek-v4.1-flash-jev
you can make any open source model behave like jev with just a bit of inference engineering. it's shockingly easy. to prove it, we built a new endpoint we're calling deepseek-v4.1-flash-jev. see the demo below. here's how it's done: sglang (an inference engine) offers a Show more
Related terms
Glossary definitions related to this entry.
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From the community
Posts from builders shipping with Jev right now.
Vercel's fx safety reviewer, 18x faster
We're seeing extraordinary results from @typesafeai. Default mode in 𝚏𝚡 is auto, with a safety reviewer analyzing every command. That reviewer runs on GPT Luna today. Jev is up to 18x faster (p95) *and* more accurate. It's coming to @vercel AI Gateway and likely new default.
@fazxes
We benchmarked fx auto mode (safety) classifier with @typesafeai's Jev. tl;dr: ~5-18x faster and more accurate than 𝚐𝚙𝚝-𝟻.𝟼-𝚕𝚞𝚗𝚊, our current top choice
Jev lands on OpenRouter
Jev by @typesafeai is now on OpenRouter, in beta. Jev is a System One model. Instead of generating text, it takes your app's state plus a typed question and returns a typed decision with a probability attached. There is no JSON prompting, parsing layer, and nothing to validate Show more
700 leads scored for $0.09
JEV is INSANE. We gave it 700 high-intent leads and personalised outreach messages. In 40 seconds, it predicted how each message would perform, assigned a confidence score and detected lead-message mismatches. All for just $0.09. JEV can also score leads, analyse buying Show more
Beating Gemini Flash Lite on an eval
Ran @typesafeai's Jev against an existing classifier eval that previously used Gemini 2.5 Flash Lite. It won both on quality (saturated the eval) and speed (6x)
Browser Use Ultrafast, powered by Jev
Breaking: Browser Use + Jev = Ultrafast ⚡ Findings flights took 7s and cost only $0.0039 🤯 > new action space every step > DOM state space > small LLM fallback to type (this video is at 1x speed btw) Built a tiny open source browser agent. try it below ↓
A really smart switch statement
hype-free explanation of jev: jev does not replace gpt / claude jev is just a *really* smart switch statement like if 2016 ml classifiers got 2026 levels of intelligence it's a new* type of tool that will make a lot of workloads insanely fast, cheap, and accurate * = and by Show more
@CompleteSkeptic
After co-inventing ChatGPT, I kept asking myself: why have superhuman chat models not led to AGI? I’ve spent the last 2 years in stealth building a new way to train models (RLCD), and a new type of frontier AI model that we are releasing today: Jev • 20-200x faster • 40-400x