How to try Jev without an invitation: a simple first test

Jev is a decision model. You give it some information and a specific question; it returns a structured decision. A yes-or-no question produces a number between zero and one. Jev is not an ordinary chat assistant that writes an explanation. S36 If you encountered an invitation or waitlist for direct TypeSafe access, there is another route. OpenRouter explicitly says any valid OpenRouter API key can call Jev through its Decisions API. A separate TypeSafe account and waitlist are unnecessary for this route. S36

See it before installing anything

Open Jev Lab on OpenRouter. Its examples show message triage, decisions about agent actions, and other tasks. You can inspect the input, code, and results to learn the format of a Jev question. S38 To run your own API request, you need an OpenRouter account, an API key, and available credit. OpenRouter bills the usage to your account; check the current rate on the model page before you begin. S36 S16

“Install” is slightly misleading here. The model runs remotely and your computer sends a request to it. On Windows, the first test below needs no Python, Node.js, or Jev installation. The built-in PowerShell and an internet connection are enough. For background on access options and pricing, see our access guide.

Create a key with a spending limit

Create an account on OpenRouter, open API key settings, and create a key. Set a small spending limit so an experiment cannot use more than you intend. OpenRouter recommends a limit on every key. Copy the key when it is created, and never paste it into a public discussion, screenshot, or website source code. S37 Add credit in your OpenRouter account if necessary. You do not need a TypeSafe registration for this route. S36

Your first YES/NO test on Windows

Open the Start menu, type PowerShell, and launch it. Copy the whole block below. The program will ask for your API key; the characters will not be displayed as you type. It sends Jev a simple question about a customer message and prints the result. This example does not save your key to a file.

$secure = Read-Host 'Vlozte OpenRouter API kluc' -AsSecureString
$ptr = [Runtime.InteropServices.Marshal]::SecureStringToBSTR($secure)
try {
  $key = [Runtime.InteropServices.Marshal]::PtrToStringBSTR($ptr)
  $request = @{
    model = 'typesafe/jev-1.13'
    state = @{ message = 'Please send me an invoice for order 123.' }
    questions = @{
      invoice = @{
        type = 'noul'
        instructions = 'Does the customer request an invoice?'
        criteria = @{
          true = 'The customer asks for an invoice.'
          false = 'The customer does not ask for an invoice.'
        }
      }
    }
  } | ConvertTo-Json -Depth 8
  $response = Invoke-RestMethod -Uri 'https://openrouter.ai/api/alpha/decisions' -Method Post -ContentType 'application/json' -Headers @{ Authorization = "Bearer $key" } -Body ([Text.Encoding]::UTF8.GetBytes($request))
  $yes = [double]$response.answers.invoice.noul
  'ANO: {0:P1} | NIE: {1:P1}' -f $yes, (1 - $yes)
}
finally {
  if ($ptr -ne [IntPtr]::Zero) { [Runtime.InteropServices.Marshal]::ZeroFreeBSTR($ptr) }
  Remove-Variable key, secure -ErrorAction SilentlyContinue
}

A high YES value is expected because the sentence asks for an invoice. The exact number may change slightly between runs. This calls model typesafe/jev-1.13 through OpenRouter's POST /api/alpha/decisions endpoint. The noul question type represents a yes-or-no proposition. S36

What our small experiments showed

In our own test, Jev correctly identified “Please send me an invoice for order 123” as an invoice request. We also tried questions about sports results and political events. Some football numbers were unusually decisive early in the first half. Putting several matches into one state with ambiguous question mapping produced suspiciously similar answers; separate, precisely described matches changed the results. These were informal experiments, not an accuracy study or evidence that Jev can predict the future.

Begin instead with examples whose answers you know: “Does the customer ask for an invoice?”, “Does this message contain a complaint?”, or “Is this text an event invitation?” Supply only the details needed for that judgment. Do not automatically interpret the returned number as the real-world chance of a future event. For consequential decisions, compare it with labeled examples and send uncertain cases to a person. Our guide to how Jev works explains the question types and their limits.

If the test fails

A 401 error usually points to an invalid API key. If you see an insufficient-credit message, inspect your OpenRouter balance and key limit. If a request succeeds but the result makes no sense, check the state text, the instructions, and what your two criteria mean before changing models. S36 Keep the key on your own computer or server, never in public page code. S37

JEV.sk is an independent information site. We do not operate the Jev model or OpenRouter.