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FREE JEV AI TOOLS
Free AI Tools Powered by Jev
Four free tools built with Jev AI. Just paste your text and get results — no sign-up, no API key.
AI Spam Detector
Check a message for spam or phishing.
AI Sentiment Analyzer
Score tone on a scale you choose.
AI Email Sorter
Decide what to do with an email.
We do not store the text you submit or include it in analytics.
Want to try your own Jev questions?
Use the live developer Playground to run up to six Choice, Score, and Noul questions in one request and inspect real answers, probabilities, latency, and cost.
Open the live Jev Playground →JEV API PRICING
Jev cost calculator: compare input-token costs
Estimate monthly spend at current standard input rates for Jev, GPT-5.6 Terra, and Claude Sonnet 5.
Enter a token count or use K, M, and B shorthand.
tokens
Quick estimates
Estimated monthly input cost
At this volume
For 1M input tokens, Jev is 97.9% less and saves $1.96 versus GPT-5.6 Terra or Claude Sonnet 5.
Input-token prices only. Estimates use standard API rates and exclude LLM output tokens, caching, batch discounts, taxes, and provider fees.
Prices checked September 19, 2026.
WHAT IS JEV AI?
A decision model, not a chatbot
Jev is TypeSafe AI’s first System One model: it turns text or structured state into typed decisions and probabilities.
Instead of generating paragraphs one token at a time, the TypeSafe Jev model evaluates focused questions in parallel. That makes it useful for classification, routing, scoring, verification, and other decisions that software needs to consume directly.
Read the official System One overviewJev typed output
Possible outputs are defined before the call, so application code does not need to parse free-form prose.
Parallel questions
Multiple focused questions can share one state and be evaluated independently in the same request.
Calibrated uncertainty
Probabilities and confidence help software decide when to act and when to escalate for review.
$0.042 per million input tokens
TypeSafe currently charges for input tokens while Jev output tokens are free.
CHOICE · SCORE · NOUL
Jev’s three typed question primitives
Choose the primitive that matches the shape of the decision your software needs. Each returns a constrained result rather than generated text.
Choice
Which option fits?
Pick one item from a fixed set, such as routing a support ticket to billing, technical support, or sales.
Returns: choice, probabilities, confidence
Score
Where does it fall on a scale?
Evaluate ordered levels such as low, medium, high, and critical, with a probability distribution across the rubric.
Returns: score, legend, probabilities, confidence
Noul
How likely is this to be true?
Ask a clear yes-or-no question and receive the probability of yes, from 0 to 1.
Returns: noul probability
JEV API KEY & SDKs
Jev Python, Node, LangChain, and gateway quick starts
Get a Jev API key directly or use an established integration. These links cover the current Python example, Node SDK, LangChain package, and Vercel AI Gateway model.
Get a Jev API key
console.typesafe.ai
Sign in to the TypeSafe Console, create a direct API key, and use jev-latest with POST /v1/systemone.
Open TypeSafe quick startJev Python example
pip install typesafe-sdk
Use TypeSafeClient with Choice, Score, and Noul objects. The official package supports synchronous and asynchronous calls.
View the Python SDK exampleJev Node SDK
npm install @typesafe-ai/sdk
The official JavaScript and TypeScript client supports Node.js 20 or newer and infers answer types from your questions.
View the Node SDK exampleJev LangChain integration
pip install langchain-typesafe
LangChain exposes Jev through TypeSafeClassifier for typed classification inside agents, middleware, and routing flows.
Read the LangChain Jev guideVercel AI Gateway
typesafe-ai/jev
Use Vercel’s AI SDK evaluate API with a Vercel AI Gateway key and the TypeSafe provider route.
View the Vercel model pageCOPY-PASTE JEV CODE EXAMPLES
Run Jev with Python, Node, LangChain, or Vercel
These minimal examples follow the current provider documentation. Set the required API key in your environment before running them.
PythonJev Python example
pip install typesafe-sdkfrom typesafe_sdk import Choice, TypeSafeClient
with TypeSafeClient() as client:
response = client.system_one(
state="I was charged twice. Please refund the duplicate.",
questions={
"route": Choice(
instructions="Which team should handle this?",
criteria={"billing": None, "technical": None},
)
},
)
print(response.choices["route"].choice)Node.jsJev Node SDK example
npm install @typesafe-ai/sdkimport { choice, TypeSafeClient } from "@typesafe-ai/sdk";
const client = new TypeSafeClient();
const response = await client.systemOne({
state: { document: "I was charged twice. Please refund it." },
questions: {
route: choice("Which team should handle this?", {
billing: null,
technical: null,
}),
},
});
console.log(response.answers.route.choice);LangChainJev LangChain example
pip install langchain-typesafefrom langchain_typesafe import Noul, TypeSafeClassifier
classifier = TypeSafeClassifier()
response = classifier.invoke(
state="The deploy failed twice. Customers are seeing 500s.",
questions={
"urgent": Noul(
instructions="Does this need attention right now?"
)
},
)
print(response.nouls["urgent"].noul)VercelJev Vercel AI Gateway example
npm install aiimport { experimental_evaluate as evaluate } from "ai";
const result = await evaluate({
model: "typesafe-ai/jev",
state: "The support agent issued a full refund.",
questions: {
refunded: {
type: "boolean",
instructions: "Was a refund issued?",
},
},
});
console.log(result);JEV VS GPT-5.6 · JEV VS CLAUDE
Use Jev and LLMs for different jobs
The price gap is real, but this is not an equal-capability comparison. Jev specializes in fast, constrained decisions; general-purpose LLMs handle open-ended generation and reasoning.
| Dimension | Jev | GPT-5.6 Terra | Claude Sonnet 5 |
|---|---|---|---|
| Input price per 1M tokens | $0.042 | $2.00 | $2.00 |
| Output price per 1M tokens | Free | $12.00 | $10.00 |
| Primary output | Typed decisions and probabilities | Generated text and structured output | Generated text and structured output |
| Best fit | Routing, classification, scoring, verification | Reasoning, code, tools, broad generation | Reasoning, writing, code, agents |
| Not designed for | Chat, prose, code, long explanations | Ultra-cheap focused decisions | Ultra-cheap focused decisions |
Pricing uses current standard API rates. Real costs vary with output length, caching, batch processing, long-context tiers, gateways, and regional options.
INDEPENDENT JEV REVIEW
When Jev is the wrong tool
A constrained output can be structurally valid and still be the wrong judgment. Test accuracy and confidence thresholds on your own data before automating consequential decisions.
Review the official model limitsIt does not generate prose
Jev does not write replies, explanations, code, or creative content. Pair it with an LLM when you need generated language.
Typed does not mean factually correct
The answer stays inside your declared schema, but the selected option or probability can still be wrong.
English is currently strongest
TypeSafe says other languages, including CJK scripts, are supported but may not perform equally well.
High-stakes use needs safeguards
Use thresholds, deterministic checks, human review, and task-specific evaluation instead of treating confidence as a guarantee.
JEV AI FAQ
Frequently asked questions
Is this the official Jev AI website?
No. jev-ai.dev is an independent, unofficial calculator and guide. TypeSafe AI publishes Jev and maintains the official website and documentation.
What is Jev AI?
Jev is TypeSafe AI’s first System One model. It accepts text or structured state and returns typed Choice, Score, or Noul decisions with probabilities instead of free-form prose.
What is a System One model?
A System One model makes fast, focused judgments that software can use directly. It evaluates shared state against typed questions and returns constrained answers and probabilities rather than generated prose.
How much does Jev cost?
Jev 1.13 is currently priced at $0.042 per million input tokens. Output tokens are free. Gateway fees, taxes, discounts, and future pricing changes are not included.
Is Jev free?
Jev API usage is not generally free: TypeSafe lists a per-input-token price. This site lets you try limited Jev requests with our server-side key for free, and the independent cost calculator is also free.
Can I try Jev free in this playground?
Yes. The Playground returns real Jev answers without requiring an account or API key. Shared rate limits apply, and we do not store the state or questions you submit.
How do I get a Jev API key?
Use the TypeSafe Console for a direct key, or create a Vercel AI Gateway key and use its Jev model ID.
Can I use Jev without the TypeSafe waitlist?
Jev is currently listed on Vercel AI Gateway, which uses its own account and API key. Provider access and availability can change, so verify the current model page before integrating.
Does Jev hallucinate?
Jev cannot return a value outside the answer shape you define, but schema compliance is not the same as factual correctness. Its judgment can still be wrong, and calibration does not guarantee any individual answer.
What are Choice, Score, and Noul?
Choice selects one option from a fixed set. Score evaluates ordered levels. Noul returns the probability that a yes-or-no statement is true.
Can Jev replace GPT or Claude?
No. Jev is built for focused typed decisions. GPT and Claude remain better suited to chat, open-ended reasoning, writing, code generation, and explanations.
What are the main Jev alternatives?
Alternatives include structured-output calls to general LLMs, dedicated classification models, embeddings plus a classifier, and deterministic rules. The right choice depends on accuracy, latency, cost, and whether you need generated explanations.
What is Jev bad at?
Jev is a poor fit for free-form text, creative work, coding, long explanations, images, audio, video, and tasks that require slow multi-step reasoning inside one answer.
What are Jev rate limits and context limits?
TypeSafe currently documents 250,000 tokens per second, 1,200 requests per minute, a 64K total request budget, and a 32K limit for state plus the longest question. Rate limits may change without notice.
How accurate is this calculator?
It applies published standard input-token rates to the token volume you enter. It does not estimate output usage, tokenizer differences, caching, batch discounts, taxes, gateway fees, or model accuracy.
LAST UPDATED
September 22, 2026
Updated with a live multi-question Jev Playground, browser-based cost calculator, copy-paste SDK examples, current Jev 1.13 pricing and limits, model comparison, limitations, and FAQ.
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Check the latest TypeSafe documentationSpot an outdated price or limit? Email a correction