adhere

A linter for rules a normal linter cannot check, such as “business logic should live in services” or “modules should expose lots of functionality behind a small API”. You can write a rule as a Markdown file, with code that shows it:

---
description: A third-party API going offline should not also take our app down.
---

Our APIs should not depend on a third-party API on a critical path. The
user-facing side should be unaffected if it goes offline, and ingestion should
happen in a separate, asynchronous process.

## Should

```ts
import db from "./lib/db";
import googleMaps from "./lib/maps";

// GET /api/restaurants/:zipCode reads only our own database.
export async function findRestaurants(zipCode: string) {
  return db.restaurants.find({ where: { zipCode } });
}

// A scheduled job copies new restaurants in, off the request path.
export async function syncRestaurants(since: Date) {
  const restaurants = await googleMaps.findAll({ updatedSince: since });
  await Promise.all(restaurants.map((restaurant) => db.restaurants.upsert(restaurant)));
}
```

## Should not

```ts
import googleMaps from "./lib/maps";

// GET /api/restaurants/:zipCode
export async function findRestaurants(zipCode: string) {
  // When Google Maps is down, slow, or over quota, so is this endpoint.
  return googleMaps.findAll({ where: { zipCode } });
}
```

adhere asks Jev, TypeSafe AI’s System One model, whether each file breaks each rule. Jev answers with a calibrated probability. adhere reports each rule whose probability is above a threshold, and shows the part of the file Jev points at. The report looks like Oxlint’s, the linter vp lint runs:

Rules a normal linter can check exactly, such as a banned import or a type error, belong in that linter. adhere validate lists the rules Jev thinks a linter could check, and finds rules that contradict each other.