Skip to content
JevDirectory.org
CommunityTools & Integrations17 starsVerified 2026-09-22

jev-belay

A Claude Code Stop hook that reads the turn transcript locally and spends one four-question Jev call only when files changed with no passing check since, blocking unverified done claims.

Category
Tools & Integrations
Published by
Community
Author
valentynkit
Added
2026-09-22
Tagscommunityjavascriptclaude-codecoding-agentguardrailsagents

Highlights

  • Measured AUROC 0.976 for telling a false done from an honest one over 100 labeled stops, versus 0.777 for wording alone.
  • One Jev call covers four questions for $0.00005, with 1,222 median input tokens and output free.
  • At the shipped 0.70 threshold it blocks 8 turns in 100, 7 of them rightly, and Jev answers in 346 ms at the median.
  • Only 17.7% of stops reach the question; every other stop costs a local transcript read and no network.
  • A turn with no file edits never reaches the question, so a read-only tests-pass claim passes through.

Quickstart

json
{
  "env": { "TYPESAFE_API_KEY": "YOUR_API_KEY" },
  "hooks": { "Stop": [{ "hooks": [{ "type": "command", "command": "node ~/src/jev-belay/belay.mjs", "timeout": 25 }] }] }
}

Watch out

MIT-licensed. Needs Node 20+, Claude Code 2.1.196 or newer, and a TypeSafe API key; every error path lets the turn end.

More like this

22GitHub stars
A security hook for coding agents that asks Jev three typed questions before every tool call and scans tool results for prompt injection, with adapters for Claude Code, Codex, Copilot CLI, Gemini CLI, Cursor, pi, OpenCode and ACP.
Tools & Integrations#community#javascript#agents
Communityjev-guard
132GitHub stars
Pi extension that supervises a coding agent with Jev judgments: it holds risky tool calls, checks writes against project Markdown rules, and feeds most issues back to the agent as a steer instead of interrupting you. The conscience is beta and off by default.
Tools & Integrations#community#typescript#guardrails
Communitypi-warden
89GitHub stars
A collection of 26 production-ready agent skills for Claude Code, Cursor, Kiro, Windsurf, and OpenCode; four skills call TypeSafe Jev for calibrated Score and Noul judgments and fall back to heuristics when it is unavailable.
Tools & Integrations#community#python#skills
Communityskills
Back to all resources

From the community

Posts from builders shipping with Jev right now.

Follow @typesafeai

The open System One roundup

Jev 发布没几天,开源社区已经开始疯狂复刻了🔥 最值得推荐的五个模型: 1、Laya 421M:原生决策模型,支持 Mac 2、Decider-2B:最像 Jev,基于 Qwen3.5 3、NanoJev 0.6B:专门的 Decision Head 4、Reflex:Qwen3.5 + Direct Logits 5、System-One 4B:专门做概率校准 Show more

小墨同学
小墨同学
@xiaomovps

Jev 刚发布没几天,开源社区就出现了同款🔥 Decider-2B模型,是基于 Qwen3.5-2B 做了特殊调整 它和 Jev 模型是一样的 只做选择 评分和判断 不是文本类的 LLM 模型 但两者还是有几个明显区别: 1、模型 Jev:闭源 System One Model Decider:Qwen3.5-2B,约 1.9B 参数,Apache 2.0 开源 2、价格

Image
Reply

The launch post

Trading bot, one decision per block

Classifying 1,500 real emails

this model is actually insane at email classification i tested it on 1500 of my own emails to see how well it works and I am blown away

Diogo Almeida
Diogo Almeida
TypeSafe AI
@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

Reply

Fast browser use with Stagehand

we built blazing fast computer/browser use with Jev + @Stagehanddev. this task cost $0.001 and executed at near instant speed (in a remote browser btw) the loop: observe the page, send a11y tree as state + actions as questions, Jev decides the next action, then Stagehand Show more

Diogo Almeida
Diogo Almeida
TypeSafe AI
@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

Reply

LLM-as-a-judge, sped up

Jev has spoken. It picked which model is AGI. 20–200x faster. 40–400x cheaper. This could make things like LLM-as-a-judge insanely fast and nearly free. (I tried a bunch of prompts and still didn’t burn through $0.10.)

Image
Diogo Almeida
Diogo Almeida
TypeSafe AI
@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

Reply