Last updated: 2026-11-02 · Project descriptions from public demos and author posts
The Jev AI 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
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
jev-ultrafast
Browser Use's agent with Jev as its decision layer — completed a Zürich→London Google Flights search in 7.1 seconds.
mobile-jev
Droidrun's phone agent drove Uber on a real Android device: 9 actions in ~21 seconds (no booking completed).
typesafe-computer-use
Computer-use agent with Jev as the cheap gatekeeper for every action.
heist-one
Jev runs the guard AI logic in a heist game demo — decisions, not scripts.
Infrastructure & tooling
jev-guard
Rates every agent tool call as deny / ask / allow against your rules before execution.
pg-jev
Adds plain-language filtering to Postgres queries via Jev decisions.
HA-Jev
Turns Jev answers into Home Assistant entities for smart-home logic.
jevmeter
Scores every sentence of a video debate for about $0.05 total.
Typewriter
Steve Krouse's live typing demo — 16 Jev judgments update in real time as you type.
jev-trader
Market-signal experiments. Independent testing showed Jev does no better than a coin flip on short-horizon prediction — see the rule.
What the first month says
Three patterns are worth reading out of this directory. First, the reproducers moved fast: openjev existing at all is strong evidence that the typed-decision interface — not just the hosted model — is the product. Second, the winners are cost-shaped: nearly every useful project uses Jev as a cheap gatekeeper in front of something expensive — an agent’s tool calls, a database query, a generation pass — not as the star of the show. Third, the failures are instructive: experiments that tried to make Jev predict the future landed at coin-flip level, exactly what its design implies.
How projects get in
There is no submission form and no paid placement. A project enters this directory when it does something real and demonstrable with Jev — usually spotted via its Hacker News thread or GitHub topic feed by the automated tracker, then verified and described by the editor. Projects that only wrap the API without a working demo are skipped, and wherever independent testing contradicted an author’s claim, we say so (see jev-trader above).
Reading the numbers honestly
Latency and cost figures in the cards come from the project authors’ own posts and demos. Where we could reproduce them independently, we did; where we couldn’t, treat them as reported values. The ecosystem is a month old — expect churn, abandoned repos and API drift, and pin your dependencies.
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.