Is-odd-jev – check if a number is odd, with a calibrated probability

Developer alxcrt published is-odd-jev, an npm package that determines whether a number is odd using the TypeSafe "jev-latest" model and returns a calibrated probability rather than a boolean, e.g. { odd: true, p: 0.999, ms: 71, output_tokens: 3 } for 5 and { odd: false, p: 0.002 } for 4. The package requires Node 18+, has zero dependencies, and can be called either with a waitlisted direct TYPESAFE_API_KEY or through the Vercel AI Gateway as typesafe-ai/jev, where probabilities come back rounded to about 2 decimal places and the free tier is rate-limited. Releases publish automatically from GitHub Actions via npm trusted publishing, requiring npm >= 11.5.1 for OIDC.

Check whether a number is odd, using a System One model, with a calibrated probability. npm i is-odd-jev js const isOdd = require 'is-odd-jev' ; await isOdd 5 ; // { odd: true, p: 0.999, ms: 71, output tokens: 3 } await isOdd 4 ; // { odd: false, p: 0.002, ms: 88, output tokens: 3 } npx is-odd-jev 5 is-odd 2014 returns a boolean. It cannot tell you how sure it is. is-odd-ai 2023 asks an LLM, which returns a string you then parse, and which will happily invent a confidence score if you ask it for one. is-odd-jev returns p — the model's actual probability that n is odd, computed from the distribution rather than narrated. Jev's Noul primitive has no confidence field, because the probability is the answer. If you need a symmetric certainty: js const { odd, p } = await isOdd n ; const confidence = Math.abs p - 0.5 2; Which lets you do the thing you could never do with an LLM: if confidence = 0.95 ship odd ; else escalateToHuman n ; Pick that threshold by measuring it on a held-out set, not by intuition. Node 18+. Zero dependencies. | env | default | |---|---| | TYPESAFE API KEY | — | | AI GATEWAY API KEY | — fallback, see below | | TYPESAFE BASE URL | https://api.typesafe.ai | | TYPESAFE DEFAULT MODEL | jev-latest | Direct TypeSafe keys are waitlisted. Vercel AI Gateway https://vercel.com/docs/ai-gateway serves the same model as typesafe-ai/jev with no waitlist, so this works instead: export AI GATEWAY API KEY=... npx is-odd-jev 5 TYPESAFE API KEY wins if both are set. Two things genuinely differ through the gateway: - Probabilities come back rounded , usually to 2dp — you get 0.99 , not 0.999 . - The free tier is rate-limited hard on this model. Fine for one number, not for a loop. Under the hood the gateway calls a Noul a boolean and its answer probability , and takes the model in a header rather than the body. This package handles that; if you are calling it yourself, experimental evaluate from ai@7 speaks it natively: js import { experimental evaluate as evaluate } from 'ai'; const { answers } = await evaluate { model: 'typesafe-ai/jev', state: { n: 5 }, questions: { odd: { type: 'boolean', instructions: 'Is n odd?' } }, } ; { "model": "jev-latest", "state": { "n": 5 }, "questions": { "odd": { "type": "noul", "instructions": "Is n odd?" } } } It cannot chat. It cannot explain itself. It cannot hallucinate. It can only tell you, with a calibrated probability, that five is odd. Releases publish themselves from GitHub Actions via npm trusted publishing https://docs.npmjs.com/trusted-publishers : the workflow swaps its OIDC token for publish rights, so there is no npm token in the repo, no secret to rotate, and no OTP prompt. npm version patch && git push --follow-tags gh release create v1.1.1 --generate-notes Publishing the release fires .github/workflows/publish.yml https://github.com/alxcrt/is-odd-jev/blob/main/.github/workflows/publish.yml , which runs the tests and then npm publish . The workflow upgrades npm first — OIDC needs npm = 11.5.1 and the runner image ships something older, which is the kind of thing that fails once and confuses you for an hour. One-time setup, on npmjs.com: the package → Settings → Trusted Publisher → GitHub Actions, repo alxcrt/is-odd-jev , workflow publish.yml . - is-odd — depends on is-number . is-even depends on is-odd . - is-odd-ai — asks GPT, parses the reply. - n % 2 === 1 — still correct, still 0 ms, still free. MIT