Jev Playground — try System One decision models online

Paste a state, ask typed questions, and watch structured judgments — probabilities, option distributions, ordinal scores — come back in milliseconds. No signup required to explore; sign in to run live calls against the real API.

How the playground works

  1. Pick any model from the catalog — swap models per request, same endpoint, same key.
  2. Enter a state (free text or JSON) and compose typed questions: Noul (yes/no), Choice (pick one of N), Score (rate on a scale).
  3. Read the structured answer: calibrated probabilities and confidence, ready for code — no text parsing, ever.

Featured models to try first

ModelVendorInput /MOutput /M
typesafe/jev-latesttypesafe$0.042Free
perplexity/pplx-decider-v1.2perplexity$0.02Free
nace-ai/drex-maxnace-ai$0.06Free
liquid/d1-ultraliquid$0.042Free
cloudflare/clefcloudflare$0.24Free

Playground FAQ

Is the EasyJev playground free?

Browsing and building questions are free; each live call is billed to your account balance at the model’s input price per million tokens. Output tokens are free on every model, and new accounts start with free credit to try it out.

Which models can I try?

The full on-sale System One catalog — Jev (typesafe/jev-latest, 1.14, 1.13), Perplexity pplx-decider, Nace.AI Drex, Liquid d1, Cloudflare Clef, Microsoft decision-1 and more. 29 models from 14 vendors behind one endpoint.

Do I need to install anything?

No. The playground runs in your browser against the live API. For code, the official typesafe-sdk works by swapping base_url to https://api.easyjev.online.

What can I ask the models?

Three typed primitives: yes/no probability (Noul), single choice with per-option probabilities (Choice, up to 255 candidates), and ordinal scoring (Score, 2–10 levels). Models never generate free text.