TypeSafe Jev

Jev is TypeSafe’s decision model, and huncho/jev calls it directly. It is the default path: every example in these docs and in the repo runs with only TYPESAFE_API_KEY set.

import { huncho, noul } from "huncho";
import { jev } from "huncho/jev";

const route = huncho("support.route", { model: jev() })
  .ask({ urgent: noul("Does this need a human within the hour?") })
  .when((a) => a.urgent.p, { enter: 0.8, exit: 0.6 }, "page")
  .else("wait");

Key

jev() reads TYPESAFE_API_KEY the first time it is called; importing the entry reads nothing. To take the key from somewhere else, build the provider yourself:

import { createJev } from "huncho/jev";

const jev = createJev({ apiKey: process.env.MY_JEV_KEY });

apiKey may be undefined or empty, in which case the variable is read instead. No key at all is a ConfigError on the first call: jev: set TYPESAFE_API_KEY or pass apiKey to createJev. A key TypeSafe rejects is a ProviderError with status 401 or 403 and retryable: false. Keys and Errors have the general rules.

Defaults

Entry	huncho/jev
Factory	createJev(options)
Ready-made instance	jev
Key from	TYPESAFE_API_KEY
URL	https://api.typesafe.ai/v1/systemone
Model id	jev-latest
Wire	systemone

jev() is the default model; jev("some-id") is another id at the same endpoint. Both return a Model, one method, evaluate.

Options

createJev(options) takes the core options every provider shares, apiKey, url, defaultModel, fetch and retries, plus:

Option	Meaning
headers	Extra request headers, merged under the Authorization header.

const jev = createJev({
  apiKey: await vault.read("jev"),
  defaultModel: "jev-latest",
  retries: 2,
  headers: { "X-Team": "support" },
});

On the wire

jev speaks the systemone dialect: the model id, the state and the questions go in a JSON body, answers come back in the canonical shape, usage arrives as input_tokens and output_tokens, and the request id is the x-request-id response header. The dialect is specified by the fixtures under fixtures/wires/systemone/, described in Wire fixtures. Transport retries 408, 429, 500, 502, 503 and 529 with backoff and fails any other status on first sight.