---
title: "@playstack/lint"
description: "Deterministic ESLint rules for portable cores, event ownership, browser extensions, and semantic design tokens."
tags: ["package","foundation","lint","eslint","extensions","chakra","free"]
---

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> **Free.** MIT licensed. Check preview availability before installing. See [package access](/docs/packages#access-policy).

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`@playstack/lint` catches integration-boundary mistakes that can be identified statically. It complements repository conventions, type-level validation, and `playstack doctor`; it does not replace them.

## Install and configure

The plugin supports ESLint `^9.0.0 || ^10.0.0`, all six rules and the four presets from both ESM and CommonJS configs. Use a Node version supported by the ESLint major you select; the broader Playstack engine range does not override a tool's own engine requirements.

```sh
npm install --save-dev @playstack/lint eslint
```

```js
import { configs } from '@playstack/lint'

export default [
  configs.recommended,
  {
    ...configs.extension,
    files: ['apps/extension/src/background/**/*.{ts,tsx}'],
  },
  {
    ...configs.chakra,
    files: ['packages/playstack-ui/src/**/*.{ts,tsx}'],
    rules: {
      ...configs.chakra.rules,
      '@playstack/semantic-tokens-only': ['error', { tokens: ['fg.default', 'bg.canvas', 'border.default'] }],
    },
  },
]
```

`extension` and `chakra` deliberately omit `files`; consumers must scope them to the surfaces where those contracts apply. Use `configs.all` only when every source file belongs to all three domains.

## Presets and rules

| Preset        | Rules                                                              | Boundary                                                                             |
| ------------- | ------------------------------------------------------------------ | ------------------------------------------------------------------------------------ |
| `recommended` | `no-process-env-in-core`, `no-consumer-internal-handler`           | Keeps portable core configuration explicit and transactional handlers package-owned. |
| `extension`   | `no-worker-memory-state`, `no-worker-long-timer`, `no-remote-code` | Enforces disposable MV3 worker state and bundled executable code.                    |
| `chakra`      | `semantic-tokens-only`                                             | Restricts selected style properties to an explicit semantic-token vocabulary.        |
| `all`         | All six rules                                                      | Combines the presets without assigning file scopes.                                  |

`no-worker-long-timer` reports dynamic delays and literal delays over 10 seconds by default. Configure `maxDelayMs` only when the extension has a documented lifecycle reason; longer work should use persisted intent and the alarms API.

`semantic-tokens-only` accepts `tokens` and `properties` allowlists. This lets an application own its theme vocabulary rather than inheriting hardcoded visual values from Playstack.

## CLI composition

```sh
npx playstack lint init --diff
npx playstack lint init
```

The [Playstack CLI](/docs/cli/lint-skills) can materialize a managed flat-config fragment from `playstack.json`. Direct ESLint composition remains supported when the application needs a custom file layout.

Rules expose no fixes unless a transformation can preserve semantics; the initial rule set reports only.

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## API entry points and requirements

Reference snapshot: `@playstack/lint@0.1.0-beta.1`. Import only the entry point your runtime needs. Paths below are relative to the installed package; use **Go to Definition** in your editor to inspect exact parameters, return types and overloads. Do not import the declaration-file paths directly.

| Public entry point | Declaration file |
| --- | --- |
| `@playstack/lint` | `./dist/index.d.ts` |
| `@playstack/lint/package.json` | No TypeScript declaration (asset or metadata export). |

Node.js engine requirement: `>=20`. This is not a claim that every entry point works in browsers or Workers.

### Peer dependencies

Keep existing framework versions that satisfy these ranges. Install optional peers only when using the corresponding adapter. The package manager resolves ordinary dependencies separately.

| Peer | Compatible range | When needed |
| --- | --- | --- |
| `eslint` | `^9.0.0 \|\| ^10.0.0` | Required by the package. |

For a complete first program, start with [Getting started](/docs/getting-started). For API lookup and partial-example conventions, see [Reading the reference](/docs/packages#reading-the-reference). Provider failures, lifecycle requirements and application responsibilities remain described in the guide above; types alone do not establish production safety.

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