Developers

How to use the hosted Jev API

One endpoint: send a state plus typed questions, get structured answers back. Auth with a jv_live_ key from this site — prepaid input tokens, output free. Upstream TypeSafe keys stay on our servers.

Source reference:

TypeSafe AI official announcement blog post

Create your API key →See pricing

1. The endpoint

Every call is a POST to https://jevtypesafe.org/api/v1/decide, authenticated with a Bearer token. Put your key in JEV_API_KEY (never commit it).

Header: Authorization: Bearer jv_live_…
Header: Content-Type: application/json
Create keys on Account after buying a prepaid pack (or using monthly free tokens).

curl

curl https://jevtypesafe.org/api/v1/decide \
  -H "Authorization: Bearer $JEV_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "state": "Customer: I was charged twice and nobody has replied for 3 days.",
    "questions": {
      "route": {
        "type": "choice",
        "instructions": "Where should this go?",
        "criteria": { "billing": "money", "bug": "broken", "account": "login" }
      },
      "urgency": {
        "type": "score",
        "instructions": "How urgent is this?",
        "criteria": ["routine", "today", "urgent", "critical"]
      },
      "escalate": {
        "type": "noul",
        "instructions": "Escalate to a human now?"
      }
    }
  }'

Python

import os
import requests

resp = requests.post(
    "https://jevtypesafe.org/api/v1/decide",
    headers={
        "Authorization": f"Bearer {os.environ['JEV_API_KEY']}",
        "Content-Type": "application/json",
    },
    json={
        "state": "Customer: I was charged twice and nobody has replied for 3 days.",
        "questions": {
            "route": {
                "type": "choice",
                "instructions": "Where should this go?",
                "criteria": {"billing": "money", "bug": "broken", "account": "login"},
            },
            "urgency": {
                "type": "score",
                "instructions": "How urgent is this?",
                "criteria": ["routine", "today", "urgent", "critical"],
            },
            "escalate": {
                "type": "noul",
                "instructions": "Escalate to a human now?",
            },
        },
    },
    timeout=30,
)
resp.raise_for_status()
print(resp.json())

TypeScript

const res = await fetch("https://jevtypesafe.org/api/v1/decide", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.JEV_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    state: "Customer: I was charged twice and nobody has replied for 3 days.",
    questions: {
      route: {
        type: "choice",
        instructions: "Where should this go?",
        criteria: { billing: "money", bug: "broken", account: "login" },
      },
      urgency: {
        type: "score",
        instructions: "How urgent is this?",
        criteria: ["routine", "today", "urgent", "critical"],
      },
      escalate: {
        type: "noul",
        instructions: "Escalate to a human now?",
      },
    },
  }),
});

if (!res.ok) throw new Error(await res.text());
console.log(await res.json());

Test your key — run this exact request against the live endpoint, once:

Sends the request above to https://jevtypesafe.org/api/v1/decide with your key and bills one small decision (≈ $0.0004 avg). Your key stays in your browser. In production, keep it server-side.

2. The request body

Two required fields:

state — context string (ticket text, email body, review, etc.). Max 4,000 characters.
questions — a map of names → question objects. All questions in one request share the state and run in one round trip.

3. The three question types

choice — pick one option

Pass a criteria map of labelled options. Response includes the winning key, per-option probabilities, and confidence.

choice

"topic": {
  "type": "choice",
  "instructions": "What is the primary issue?",
  "criteria": {
    "billing": "billing or payment problem",
    "bug": "the product is broken",
    "account": "login or access"
  }
}

score — position on a scale

Pass an ordered criteria array (2–10 levels). Response returns a numeric score plus the distribution over levels.

score

"severity": {
  "type": "score",
  "instructions": "How urgent is this?",
  "criteria": [
    "routine",
    "handle today",
    "urgent",
    "critical, about to churn"
  ]
}

noul — calibrated yes / no

No criteria — only instructions. Response is a probability in [0, 1].

noul

"escalate": {
  "type": "noul",
  "instructions": "Escalate to a human immediately?"
}

4. The response

Typed answers mean you branch in code — no JSON-in-string parsing. Example shape:

response

{
  "model": "jev-latest",
  "answers": {
    "route": {
      "type": "choice",
      "choice": "billing",
      "confidence": 1.0,
      "probabilities": { "billing": 1.0, "bug": 0.0, "account": 0.0 }
    },
    "urgency": {
      "type": "score",
      "score": 2.0,
      "confidence": 0.9,
      "probabilities": { "0": 0.05, "1": 0.1, "2": 0.7, "3": 0.15 }
    },
    "escalate": { "type": "noul", "noul": 0.72 }
  },
  "usage": { "input_tokens": 180, "output_tokens": 40 }
}

usage.input_tokens is what we deduct from your prepaid balance. Output tokens are free.

5. Limits & practices

Rate limit ≈ 60/min per key (plus IP / account / global caps).
Soft burn caps ≈ 2,000,000 tokens/hour and 20,000,000 tokens/day per account.
Trim state — you pay per input token.
Batch several questions in one call so they share the state cost.
Use confidence / noul thresholds to auto-handle easy cases and escalate the rest.

Get instant access

Sign in, buy a small pack on Pricing, create a jv_live_ key on Account, then call this endpoint. One balance for Core decide and every hosted tool.

Create your API key →See pricing