system-one: typed decisions from Jev, Cloudflare AI Gateway and Laya, Promise or Effect

# system-one

Typed decisions from System-1 models — TypeSafe **Jev** (directly or via **Cloudflare AI Gateway**) and **Laya** — with a Promise client and an **Effect** service sharing one set of question definitions.

You send **state** and **typed questions**; you get **typed answers with probabilities**; your code decides. The library never invents a probability, threshold, selected level, or model version it was not given.

```
pnpm add system-one                  # Promise API, zero runtime deps
pnpm add effect @effect/platform     # only for system-one/effect
```

Node ≥ 22.18, ESM only.

## Define questions

```ts
import { Question, defineQuestions } from "system-one";

const triage = defineQuestions({
  urgent: Question.boolean({
    instructions: "Does this need urgent attention?",
    criteria: { true: "Time-sensitive harm or an ongoing outage", false: "Routine request" },
  }),
  department: Question.choice({
    instructions: "Which department should handle this?",
    options: {
      billing: "Payments, refunds, invoices",
      technical: "Bugs, outages",
      sales: "Pricing",
    },
  }),
  frustration: Question.ordinal({
    instructions: "How frustrated is the customer?",
    levels: ["Calm", "Frustrated", "Very angry"],
  }),
});
```

Literal keys are preserved: `answers.department.value` is `"billing" | "technical" | "sales"`.

## Promise API

```ts
import { createClient } from "system-one";
import { jev } from "system-one/adapters/typesafe";

const client = createClient({
  model: jev({ apiKey: process.env.TYPESAFE_API_KEY!, model: "jev-1.13.0" }),
});

const result = await client.evaluate(
  { state: { message: "My payouts have failed for three days!" }, questions: triage },
  { signal, timeoutMs: 10_000 }, // optional
);

result.answers.departme