---
title: Jev — a decision model your agents can call
---

# Jev — a decision model your agents can call

## What it is

Jev is [TypeSafe's](https://typesafe.ai/) **decision model**. It generates no text at all: you hand
it a situation plus one or more typed questions, and it returns each answer with **the probability
it assigns**. That makes it the right tool for the work that never needed prose in the first place —
sorting items into buckets, picking a route, extracting a value, rating something against a rubric,
or judging whether another model's output is good enough to act on.

Because the answer arrives with a confidence, you can gate on it: act above a threshold, escalate
below it.

## Where to find it

Jev has no screen and nothing to switch on. It reaches your agents as a **skill** an AI can use plus a small **command-line tool** the agent runs — there is no server and nothing left running between calls.

You see its effect in two places: the answers your agent gives you when it used Jev to decide, and the spend it adds to your gateway credit, which you can read in **Settings → Plan & Usage**.

## How it behaves

### How an agent uses it

Jev ships as a **skill** plus a small **command-line tool** — no server, nothing left running. An
agent that has the `jev` skill runs one command per question and gets JSON back:

```bash
node scripts/jev-cli.mjs check "the deploy is safe to roll forward"
node scripts/jev-cli.mjs choose --state-file /tmp/situation.txt \
  --instructions "Which bucket?" --option bug="broken now" --option feature="new capability"
node scripts/jev-cli.mjs decide --request-file /tmp/questions.json      # several in one call
```

Nothing needs to be turned on and no key needs to be set: like Omniscio's other outside-API calls,
Jev goes through Omniscio's gateway on your account, and each call is metered to your **prepaid
credit** — the same credit that powers the built-in voices and the other gateway features. You can
see the spend in **Settings → Plan & Usage**.

The gateway reaches Jev by **two** routes, and it tries the first one first: Omniscio's own TypeSafe
account, and then the OpenRouter route as a backup. A call stops at the first route that answers, so
backup capacity is only spent when it is actually needed. You do not choose between them and there is
nothing to configure — from your side it is one call and one meter.

If you have your own OpenRouter key saved (Settings → My API Keys), it is used **only when both
gateway routes are unavailable** — never as the first choice, and never while a gateway route could
still answer.

### What it costs

Jev is metered to your gateway AI credit at TypeSafe's rate, and every call reports its own exact
cost. Typical calls land around a hundredth of a cent. Ask several questions in one call rather than
several calls — extra questions in the same call cost almost nothing extra.

### Reading the answer

Every answer comes with a confidence between 0 and 1.

- **High confidence** — act on it.
- **Low confidence** — the model is telling you it is not sure. Escalate, ask a narrower question,
  or hand the decision to a person.

A confidence is a *judgement*, not a verified fact. Never let an answer — however confident — be the
only thing standing behind an irreversible action like deleting something, sending a message, or
merging code.

### When Jev says it cannot answer

If no one can be asked — you are signed out, your gateway credit is used up, or the shared route to a
provider is unavailable — Jev says so plainly and tells you which of those it is. That is
deliberately **not** the same as an answer of "no": an agent that cannot ask you will report that it
could not ask.

### What Jev is not

- **Not a chatbot.** It writes no prose, explains nothing, and summarises nothing.
- **Not a browser agent.** This is the decision model, not TypeSafe's browsing tool.
- **Not for anything with steps.** One decision per question, phrased so it can be answered.

## Related

Other pages about an AI being given a packaged job to do: the [Use skills](use-skills.md) page for how an agent picks one up, and [Cost control](cost-control.md) for the gateway credit Jev's calls are metered against.