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…
Ecosystem
Fail open
When Jev is down or slow, the gate allows the action, including rules that would otherwise block it.
- Category
- Ecosystem
- Also known as
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- Related terms
- 4
- Directory entries
- 1
- Docs
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- Added
- 2026-09-28
Definition
Gatekeeper's hooks fail fully open. If Jev is unreachable or slow, nothing is denied, forbid rules included, because a hook that throws would break the coding session. A fresh install starts in shadow mode, which logs the verdict and changes nothing.
Fail open is the right default only when a wrong allow is cheaper than a stuck tool. jev-guard uses the opposite default on withdrawals. Pick the one that matches the cost of the action, and log the fail-open rate so a dead client does not look like a quiet gate.
Tagssafetyrouting
Related terms
Definitions that connect to this one.
Fail closedWhen the model errors, times out, or lacks evidence, the system escalates or blocks instead of allowing the action.EcosystemConfidence-gated routingUse the answer to decide what to do and confidence to decide whether to act, with per-action thresholds set by the cost of being wrong.PatternsHuman reviewThe explicit path for uncertain or high-stakes cases: route to a person instead of acting on a low-confidence answer.PatternsCoding agentThe fastest-growing corner of the Jev ecosystem: MCP servers, tool-call gates, context pruners, and skill rankers.Ecosystem
From the directory
18GitHub stars
Claude Code hooks that narrow a roster in YAML, ask Jev which handler owns a prompt, and log the band before anything is blocked.
Agents & MCP#community#python#coding-agent
Community
AgriciDaniel/gatekeeperPython
AgriciDaniel/gatekeeperPythonFrom the community
Posts from builders shipping with Jev right now.
Jev as an LLM guardrail inside Agentgateway
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
dmx.to reshapes the timeline in plain language
the next version of dmx.to will let you fully customize the timeline both with dumb rules (how did i not think of these until now lol) and smart rules using Jev (BYOK also supports vercel gateway) 🤓 you can filter 3 lvls of usefulness, tweet types, topics, etc
