TypeSafe AI · System One model

Decisions, not text.

Jev doesn't write paragraphs. You send it your app's state plus a set of typed questions, and it returns bounded decisions with probabilities — evaluated in parallel, in one pass. Try it below.

70–500 msper evaluation
$0.042per 1M input tokens
$0output tokens
64kcontext per request
jev-1.13.0current model

Three question types

Every question has instructions plus criteria that define the answer space up front. That's why Jev can't hallucinate a value outside your schema — it can only be wrong within it.

choice

Pick one

Route, classify, decide. Returns the winning option plus the full probability distribution and a confidence value.

"department": {"billing": 0.15, "technical": 0.85}

score

Rate it

Grade along a rubric you define (2–10 ordered levels). Returns a probability-weighted value — it can land between levels.

"frustration": 1.05 → "Frustrated"

noul

Yes or no, softly

A soft boolean from 0 to 1. Returns the probability the answer is yes — no separate confidence field, the number is the confidence.

"is_urgent": 0.95

Playground

Build a request below and evaluate it. Live mode calls the real Jev API through this site's proxy (your key stays server-side). Demo mode generates clearly-labeled fake answers so you can explore the UI without a key.

All questions evaluate in one API call
Plain text, a JSON object, or an array. For structured state, paste JSON — it gets sent as an object.
⚖️Your decisions will appear here.
Pick a preset or write your own state + questions, then hit Evaluate.

Jev vs. an LLM

Not a cheaper chatbot — a different output shape entirely.

JevTypical LLM
OutputTyped values from your schemaFree-form text
HallucinationCan't leave the schema (can still pick wrong)Can invent anything
SpeedOne parallel pass, 70–500 msToken-by-token decoding
Cost$0.042 / 1M input tokens, free outputPriced per input + output token
ConfidenceCalibrated probability per answerUsually absent or hand-rolled
Best forRouting, gating, scoring at volumeWriting, reasoning, explaining
The pattern: Jev makes the fast judgment calls inside your software — which queue, how urgent, auto-handle or escalate — and your code branches on the confidence. The LLM stays for the parts that need words.

Connect your API key

Live mode calls POST https://api.typesafe.ai/v1/systemone through a small proxy on this site, so your key never touches the browser.

01

Get a key

Create one at console.typesafe.ai/keys (TypeSafe early access).

02

Add it to this site

In Cloudflare Pages → this project → Settings → Environment variables, add TYPESAFE_API_KEY = your key (Production).

03

Redeploy

Hit Retry deployment (or push a commit). The status pill up top turns green when the proxy can reach Jev.