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Jev FAQ
Independent answers to common Jev AI questions: what it is, how the API works, pricing, primitives, and limits.
- Published
- Sep 20, 2026
- Updated
- Sep 20, 2026
- Last verified
- Sep 20, 2026
Quick answer
Jev is TypeSafe's System One model for structured decisions. Call POST /v1/systemone with state and Choice, Score, or Noul questions. Public input pricing was $0.042 per million tokens when last verified. This site is not TypeSafe.
Short answers. Longer treatment lives on the linked guides.
Product
What is Jev? A System One model from TypeSafe for classification, routing, and scoring. See What is Jev AI.
What is TypeSafe AI? The vendor. See What is TypeSafe AI?.
Is Jev an LLM? No. See Is Jev an LLM?.
How do I use Jev? How to use Jev then Getting Started.
Is this the official docs site? No. Official docs are docs.typesafe.ai. Read the disclaimer.
What model ID should I send? Official examples use jev-latest. When last verified that alias pointed at jev-1.13.0. Pin a version after you tune thresholds.
Building
Python package? typesafe-sdk. Guide: Jev Python. There is no official Jev model GitHub that we verified. See Jev GitHub.
TypeScript package? @typesafe-ai/sdk. Guide: Jev TypeScript.
OpenRouter / Vercel? Jev on OpenRouter and Vercel.
What is RLCD? Reinforcement Learning for Calibrated Decisions.
Can I ask several questions at once? Yes. Official docs say they run in parallel on one state.
Does confidence exist on Noul? No separate field. The noul value is the uncertainty signal.
Operations
Errors? 401, 422, 429, 529. See the API.
Languages? English is officially strongest. Test other languages yourself.
Comparisons to ChatGPT? Review and alternative pages belong on comparison sites, not here. This hub stays on learn / API / tutorial / troubleshoot.
When to use Jev
When the answer space is closed and code will consume the result.
When not to use Jev
When you need generated text, exact math, or multi-hop reasoning. See limitations.
Common mistakes
Searching for “official Jev docs” and landing here without noticing the independence banner in the footer.
FAQ
What is Jev AI?
Jev is TypeSafe's flagship System One model. It returns structured decisions, not chat. Longer page: What is Jev AI?
What is TypeSafe AI?
The company that builds Jev. TypeSafe is the vendor; Jev is the model; System One is the class.
Is Jev an LLM?
No. It understands natural language but does not generate prose. See Is Jev an LLM?
Is there an official Jev GitHub?
We did not find official model weights. Official clients are typesafe-sdk and @typesafe-ai/sdk. See Jev GitHub.
Can I use Jev on OpenRouter or Vercel?
Yes. OpenRouter documents a System One / Decisions path. Vercel AI Gateway lists typesafe-ai/jev.
Is Jev AI Hub official?
No. It is an independent educational resource and is not affiliated with or endorsed by TypeSafe.
What is a System One model?
TypeSafe's name for models that make fast structured decisions for software. Jev is the first one they published.
How do I call the Jev API?
POST https://api.typesafe.ai/v1/systemone with a Bearer token, a state, and typed questions.
How much does Jev cost?
Official docs listed $0.042 per million input tokens and free output as of 2026-09-20.
What are Choice, Score, and Noul?
Choice picks one option. Score rates an ordered rubric. Noul returns P(yes).
Can Jev be fine-tuned?
Official models docs say no customer fine-tunes or LoRAs. Customize through state and criteria.
Does Jev store my data for training?
Official models docs say Jev is not trained on customer requests or responses. Read TypeSafe's legal pages for DPA and ZDR details.
Sources
- IntroductionTypeSafe · accessed 2026-09-20 · documentation
- ModelsTypeSafe · accessed 2026-09-20 · documentation