Jev is TypeSafe AI’s first System One model. You send application state plus typed questions; it returns a choice, a score, or a yes/no probability your software can branch on. It does not write prose, code, or explanations.

What is Jev AI / the Jev model?

Jev AI is the public name for TypeSafe’s hosted decision model, currently published as jev-1.13.0 with aliases jev-latest and jev-preview. It is built for routing, triage, scoring, and gating inside software, not for chat.

No. Jev is a closed, hosted API. TypeSafe has not released the weights, architecture, or training recipe. Community projects such as openjev and jevlike experiment with similar interfaces on open models, but they are not Jev.

There is no published free tier from TypeSafe. Input tokens are billed at $0.042 per million and output is free. Some independent playgrounds and the Vercel AI Gateway let you try the model under their own limits.

How do I get access to Jev?

Create an API key in the TypeSafe console at console.typesafe.ai, or call the model through Vercel AI Gateway as typesafe-ai/jev. The public endpoint is POST https://api.typesafe.ai/v1/systemone.

Can Jev generate text?

No. TypeSafe documents that jev-1.13 is not trained to generate text. Use Jev for the branch, then a general LLM if a person needs a written reply.

Independent Jev AI guide · TypeSafe System One · September 2026

Jev AI: TypeSafe’s model for typed decisions.

Jev is not a chatbot. Send it application state and it returns a choice, a score, or a yes/no probability your code can branch on — currently billed at $0.042 per million input tokens, with output free.

See the decision shape What is Jev AI?

jev-1.13.0Current public alias

$0.042 / 1MInput tokens, output free

choice · score · noulThree typed outputs

Hosted APINot open weights

software state → typed output

state

"The customer has been billed twice and wants a refund today."

Jev / System One

decision

choicebilling0.98

noulescalate0.92

The contract

Messy text in.
Typed Jev decision out.

Jev’s value is not another chat window. It is a fast, typed branch your application can consume. The panel below is a local shape demo so you can see the interface before you call the hosted model.

shape demo · not the hosted Jev API local example

state0c

questions3 typed decisions

choicetopicbilling, bug, account, feature

scoreseverity0 to 3 risk level

noulescalateyes/no probability

This panel shows the contract: messy state in, typed values out. It is a local example, not TypeSafe Jev. For a live call, use the Jev API guide or the official console.

Typed output will appear here.

Jev primitives