Jev Python SDK tutorial

1. Install and authenticate

Keep the API key on the server. The SDK reads TYPESAFE_API_KEY from the environment, so it does not need to appear in application code.

python -m pip install typesafe-sdk
export TYPESAFE_API_KEY="your-api-key"

2. Make a typed decision

State carries the facts to inspect. Questions define the closed decisions you want back. This example routes a support message and separately checks urgency.

from typesafe_sdk import Choice, Noul, TypeSafeClient

with TypeSafeClient() as client:
    response = client.system_one(
        state={"message": "Stripe has failed for 3 days."},
        questions={
            "department": Choice(
                instructions="Which team should handle this?",
                criteria={
                    "billing": "Payments or subscriptions",
                    "technical": "Bugs or integrations",
                    "sales": "Pricing or account questions",
                },
            ),
            "is_urgent": Noul(
                instructions="Does the message convey urgency?"
            ),
        },
    )

3. Read the answer safely

Choice answers expose a winning label, a probability distribution, and confidence. Noul returns the estimated probability that its statement is true. Treat the result as decision data, not generated prose.

department = response.answers["department"]
print(department.choice)
print(department.probabilities)
print(department.confidence)

urgent = response.answers["is_urgent"]
print(urgent.noul)  # P(true)

4. Production checklist

Pin and log the model version, keep question identifiers stable, validate every answer before applying side effects, and send low-confidence or high-risk cases to a person.