LIVE JEV PLAYGROUND
Try Jev AI: Live Playground
Try Choice, Noul and Score in a Live Playground powered by the real Jev API. Jev is TypeSafe AI’s System One Model for structured decisions with probabilities.
An independent resource, not affiliated with or operated by TypeSafe AI. Live runs call Jev; Interactive Demo and illustrative examples do not. If live access is unavailable, the playground labels its mode.
01 / EXPLORE THE PATTERN
Jev Decision Playground
Try Jev as a classifier. Jev can classify, route, score and evaluate software state using typed questions and calibrated probabilities.
Choose one answer from your options.
Selected decision
Confidence (illustrative)80.0%
Illustrative output
Illustrative probabilities for this preset, not a Jev prediction.
This is not a live Jev call. Demo values do not measure Jev’s accuracy or speed.
02 / EXAMPLE USE CASES
One pattern. Many decisions.
Load a preset into the playground.
See what a structured decision looks like.
Customer Support Routing
Send each request to the right team.
Agent Tool Selection
Choose the tool that fits the next step.
Risk Assessment
Add a review step before a risky action.
Agent Loop Decision
Know when to continue, retry, or stop.
Urgency Detection
Check whether a message needs urgent attention.
Frustration Score
Rate a customer message against an ordered rubric.
Three question types in the Jev model
Choice
Pick one option and return the full probability distribution.
Noul
Ask a yes/no question and get the probability that the answer is yes.
Score
Rate a state against an ordered rubric and return a probability-weighted score.
Explore the request and response formats in the Jev API guide, or read our Jev AI hands-on review for recorded live results from all three primitives.
03 / A DIFFERENT OUTPUT
What is Jev AI?
Jev is TypeSafe AI’s System One Model designed for fast, structured decisions inside software.
Give it the relevant state and a focused question. Your application receives an answer it can use to choose a route, select a tool, or request a review.
Learn what Jev isTRADITIONAL LLM
Text
Text
An open-ended response
for a person to read.
JEV
State + Question
Typed Decision
+ Probabilities
A bounded answer
for software to act on.
04 / THE DECISION PATH
How Jev works
A focused question connects your application’s state to its next action.
Traditional LLM workflow
- Input
- Prompt
- Generate Text
- Parse
- Validate
- Decision
Jev workflow
- State + Structured Question
- Typed Decision
- Probabilities
A simplified comparison. LLMs also offer structured outputs; your application still needs validation and decision policies.
05 / BUILD WITH DECISIONS
Jev API
Developers can use Jev for structured decision tasks such as routing, scoring, classification, verification and agent control.
Explore the Jev APIstate → "Customer requests a refund"
question → "Which team should handle this?"
choices → [Billing, Technical, Sales]
decision → Billing
// Your application decides what happens next.
routeTo(decision)See the API guide for a request based on official documentation.
06 / CHOOSE THE RIGHT TOOL
Jev vs LLM
| Attribute | Jev | Traditional LLM |
|---|---|---|
| Primary task | Structured decisions | Text generation |
| Output | Typed decision + probabilities | Free-form text |
| Good for | Routing, scoring, classification | Writing, reasoning, conversation |
| Integration | Decision-oriented | General-purpose |
Jev is not necessarily a replacement for an LLM. They can work together: an LLM can develop a plan, while Jev evaluates a bounded decision within the workflow.
QUESTIONS, ANSWERED
A little more context.
New model. Different interface.
Here are the essentials.
What is Jev AI?
Jev is TypeSafe AI’s System One Model for structured decisions inside software. It evaluates state against typed questions and returns answers with probabilities.
Who created Jev?
Jev was created by TypeSafe AI. TryJevAI.com is an independent resource and did not develop the model.
What is a System One Model?
System One is TypeSafe AI’s term for a model focused on fast, bounded judgments. You supply context and define the answer space; the model returns a decision that code can use.
Is Jev an LLM?
TypeSafe AI describes Jev as a System One Model rather than a conventional text-generating LLM. Its interface centers on choices, scores and yes/no probabilities, rather than conversation.
What is Jev used for?
Example uses include routing support requests, selecting agent tools, classifying content, scoring against a rubric, and checking whether an agent should continue or ask for help.
Does Jev have an API?
Yes. TypeSafe AI publishes an HTTP API and SDK documentation. Vercel also lists Jev in its AI Gateway catalog. Check the current official documentation for access requirements and integration details.
Can I try Jev online?
Yes. This playground labels real TypeSafe API calls as Live Jev. When no server API key is configured, it runs an Interactive Demo with illustrative values. Choose a routing, urgency or scoring example and check the mode label before running.
Is TryJevAI.com the official Jev website?
No. TryJevAI.com is an independent demo and learning resource. It is not affiliated with, endorsed by, or operated by TypeSafe AI.