Last updated: 2026-09-20 · Project descriptions from public demos and author posts

The Jev Ecosystem

Within days of launch, developers started building on Jev's typed-decision primitive — agents, guardrails, database filters, games, and even an open-source reproduction of the interface itself. This directory tracks the notable ones.

Open-source reproduction

Reference impl.

openjev

Reproduces the Jev interface pattern on a small open model by reading typed option probabilities off the logits. The community's answer to “is this a durable primitive or a vendor wrapper?” — apparently durable.

Agents

Browser

jev-ultrafast

Browser Use's agent with Jev as its decision layer — completed a Zürich→London Google Flights search in 7.1 seconds.

Mobile

mobile-jev

Droidrun's phone agent drove Uber on a real Android device: 9 actions in ~21 seconds (no booking completed).

Computer use

typesafe-computer-use

Computer-use agent with Jev as the cheap gatekeeper for every action.

Games

heist-one

Jev runs the guard AI logic in a heist game demo — decisions, not scripts.

Infrastructure & tooling

Safety

jev-guard

Rates every agent tool call as deny / ask / allow against your rules before execution.

Databases

pg-jev

Adds plain-language filtering to Postgres queries via Jev decisions.

Smart home

HA-Jev

Turns Jev answers into Home Assistant entities for smart-home logic.

Media

jevmeter

Scores every sentence of a video debate for about $0.05 total.

Realtime UI

Typewriter

Steve Krouse's live typing demo — 16 Jev judgments update in real time as you type.

Experiments

jev-trader

Market-signal experiments. Independent testing showed Jev does no better than a coin flip on short-horizon prediction — see the rule.

Want to be listed?

Building something with Jev? It'll likely show up on Hacker News or X — our tracker picks it up from there and adds it here automatically, or reach out with a link.