You can run Jev at home with Loki as well! It’s a full agent harness github.com/wundercorp/loki
Ecosystem
Fail closed
When the model errors, times out, or lacks evidence, the system escalates or blocks instead of allowing the action.
- Category
- Ecosystem
- Also known as
- —
- Related terms
- 4
- Directory entries
- 2
- Docs
- —
- Added
- 2026-09-28
Definition
jev-guard turns timeouts, 5xx, and 429 responses into manual review, never an automatic pass. Hard rules for sanctions and large amounts run before the model is called. jev-suite fails a check closed when no evidence was retrieved, and a missing model escalates.
Fail closed is a property of the surrounding code. The model does not know the policy. The gate has to be written, tested, and logged, including the cases where Jev never answered.
Tagssafetyrouting
Related terms
Definitions that connect to this one.
Fail openWhen Jev is down or slow, the gate allows the action, including rules that would otherwise block it.EcosystemHuman reviewThe explicit path for uncertain or high-stakes cases: route to a person instead of acting on a low-confidence answer.PatternsConfidence gateA threshold on confidence that decides whether code acts, confirms first, or escalates to a person or a bigger model.Answers & ConfidenceRisk triageJev scores a transfer or a claim. Hard rules and a routing matrix in code decide whether to pass, review, or freeze.Patterns
From the directory
37GitHub stars
A Java gateway that asks Jev four questions about a deposit or withdrawal, then applies a direction-aware routing matrix in code.
Tools & CLIs#community#java#security
Community
klauswg/jev-guardJava
klauswg/jev-guardJava33GitHub stars
Four Java checkers — sponsored video, hiring fit, edit fidelity, and rental listings — that keep thresholds and vetoes in unit-tested code.
Tools & CLIs#community#java#verification
Communityklauswg/jev-suiteJava
klauswg/jev-suiteJavaFrom the community
Posts from builders shipping with Jev right now.
Loki: a self-improving harness with a Jev companion
Jev as an LLM guardrail inside Agentgateway
TypeSafe’s new Jev model is fast 🔥 and Agentgateway keeps up! In minutes, I had Jev running as a prompt guard through Agentgateway, with distributed tracing and cost tracking. Check out the example below Example: github.com/agentgateway/a… Intro to Jev: typesafe.ai/blog/introduci…
Jev reranks station suggestions in TrainLCD
提案駅のリランク判定と実測スパイクを追加する by TinyKitten · Pull Request #33 · TrainLCD/Functions github.com/TrainLCD/Funct… AIチャット機能の一部にもJevを潜ませてみるゾ
Vercel's fx safety reviewer, measured at 18× faster
@vercel 's fx uses Jev to review every command. @rauchg says it's up to 18x faster than GPT Luna and more accurate. @JoshARosen built Foreman, where Jev watches coding agents for drift, missed tests and getting stuck. @shantanugoel's Hermes agent installed an "ask Jev" skill on Show more
A game where you race Jev at spotting slop
A small game to show how fast TypeSafe's Jev actually is. Try to beat it at detecting a spam message beatjev2it.jlamberts86.workers.dev
Jev plays itself at 3D chess
got access to jev and instead of doing anything useful i made it play itself at 3D chess same model on both sides, slowly developing beef with itself you can watch jev vs jev or jump in and ruin its day chess-jev.loomens.com
@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