Jev AI — the model that returns decisions instead of words

This site is an unofficial developer handbook for people who want to use Jev AI in production. For a bilingual “what is Jev” encyclopedia, see jev101.com. We focus on shipping: API shapes, cost math, and when a decision model beats a chat LLM.

Three primitives

• Noul — yes/no with a probability of “yes”.
• Choice — pick one of up to 255 labeled options.
• Score — ordered scale (2–10 levels) with a distribution.

30-second triage example

One System One call can ask several questions at once. The JSON below is an illustrative example from the TypeSafe docs, not a measured production run.

{
  "state": "Customer email: My invoice charged twice this month and I cannot download the PDF.",
  "model": "jev-latest",
  "questions": {
    "is_support": {
      "type": "noul",
      "instructions": "Is this a customer support request that needs a human or bot reply?"
    },
    "department": {
      "type": "choice",
      "instructions": "Route this message to the best department.",
      "criteria": {
        "billing": "Payments, invoices, refunds, subscriptions",
        "technical": "Bugs, outages, API errors, product failures",
        "sales": "Pricing questions, upgrades, new purchases"
      }
    },
    "urgency": {
      "type": "score",
      "instructions": "How urgent is a reply?",
      "criteria": [
        "low",
        "medium",
        "high"
      ]
    }
  }
}

Hard numbers (official claims)

• 193.6x Faster · 444.6x Cheaper (TypeSafeAI 1.1 comparison on typesafe.ai)
• Input $42 / billion tokens · output free
• P50 latency about 0.23s · context 32,000 tokens

Tools on this site

• Pricing calculator — day/month cost at official rates
• Request builder — copy-paste noul / choice / score JSON
• API quickstart — Python + multi-question call

All 7 pages

1. Home — Developer notes for Jev AI: typed decisions with probabilities, not chat completions. Quickstart, primitives, pricing, and when to use a decision model.
2. TypeSafe AI — Who TypeSafe AI is, founder Diogo Almeida, System One naming, published speed/cost claims, and official docs links.
3. API quickstart — POST /v1/systemone with noul, choice, and score in one call. Auth, errors, backoff, and why chat-completions SDKs will not work.
4. What is Jev AI — Jev AI is not a chat model. Learn noul, choice, score, confidence vs probability, and when not to use it.
5. Pricing — Estimate daily and monthly cost at $0.042 per million input tokens. Output tokens are free. Compare against a chat LLM.
6. Primitives — Field reference for noul, choice, and score plus a request builder that copies valid System One JSON.
7. Jev vs LLM — Parallel sampling vs autoregression, latency, calibrated probabilities, and using LLM write + Jev judge together.