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System One

System One models. One API.

Access Jev through a single HTTP endpoint. Get structured choices, scores, and probabilities, with API keys, usage tracking, and credit billing in one place.

Get an API keyTry the Playground

HTTP + JSON · API key authentication · Prepaid credits

https://YOUR_SYSTEM_ONE_HOST/v1
cURL · POST /v1/systemone
curl 'https://YOUR_SYSTEM_ONE_HOST/v1/systemone' \  -H "Authorization: Bearer $SYSTEM_ONE_API_KEY" \  -H 'Content-Type: application/json' \  --data '{    "model": "jev-latest",    "state": { "message": "I was charged twice." },    "questions": {      "team": {        "type": "choice",        "instructions": "Who should handle this?",        "criteria": {          "billing": "Payments and refunds",          "support": "Technical issues"        }      }    }  }'

Start calling System One

  1. 1

    Create a key

    Create an API key in the console and save it in your server environment. The full key is shown once.

  2. 2

    Send a request

    Copy the cURL example, or use your HTTP client. No SDK installation is required.

  3. 3

    Review usage

    Check request status, credit charges, and your remaining balance in the console.

Set SYSTEM_ONE_API_KEY on your server, then send the request to the endpoint shown above. Successful evaluations use your account credits.

API documentation

Three primitives for structured decisions

Send the context as state and define the questions to evaluate. Combine Choice, Score, and Noul in one request; each question is evaluated independently against the same state.

SHARED STATE

“I was charged twice for this order. Please refund the duplicate payment.”
state.message
Illustrative example · not a live response

Choice: select an option

Define a set of options. Get the selected option, a probability for each option, and confidence.

01
billingBilling & refunds
0.92
supportTechnical support
0.06
salesSales
0.02
EXAMPLE ANSWERanswers.department.choice → "billing"

These values illustrate the response format. Run your own inputs in the playground for a real result.

Try this example live

Models and request limits

Evaluate up to 32 questions over one shared state. Requests support text and JSON inputs, up to 64 KiB.

Choose a model alias or a fixed version ID. Use GET /v1/models with your API key to see the available model list.

API documentation

Usage-based credit pricing

Requests are charged by question count and input size. Estimate the credit cost in the Playground before running an evaluation.

questions × ⌈request bytes / 4,096⌉

API pricing

Use the TypeScript SDK

Define questions with choice(), score(), and booleanQuestion(). Connect with the same API key and get typed results in your application.

Explore the SDK

Make your first HTTP request

Set SYSTEM_ONE_API_KEY on your server, then send the request to the endpoint shown above. Successful evaluations use your account credits.

Get an API key