Biome v2.0–v2.4 Knowledge Patch Skill

Biome v2.0–v2.4 Knowledge Patch

You know Biome through v1.6.x: basic lint/format for JS/TS/JSX/TSX/JSON, biome.json config, biome check/format/lint commands, Prettier-compatible formatter, ~200 lint rules, partial Astro/Svelte/Vue support.

This patch covers v2.0–v2.4 (2025-06-17 – 2026-02-10).

Index

| Topic | Reference | Key changes | |-------|-----------|-------------| | Configuration & Migration | references/config-and-migration.md | files.includes replaces ignore/include, config discovery, nested configs for monorepos | | Linting & Plugins | references/linting-and-plugins.md | Linter domains, type-aware linting, suppression comments, GritQL plugins | | Formatting & Language Support | references/formatting-and-languages.md | Assists, HTML formatter, embedded snippets, Vue/Svelte/Astro, Tailwind v4 CSS |

Quick Reference — Breaking Changes

`files.includes` replaces `files.ignore` and `files.include`

This is the most impactful v2 breaking change. Both fields merged into one.

{
  "files": {
    "includes": [
      "**",
      "!**/generated",
      "!!**/dist"
    ]
  }
}

Globs no longer auto-prepend **/ — you must write full patterns
* no longer matches /
Globs are relative to config file location, not working directory
! prefix — skip formatting/linting but still index for types (v2.3)
!! prefix — completely exclude from all Biome operations (v2.3)

See references/config-and-migration.md for config discovery and monorepo setup.

Quick Reference — Linter Domains

Framework-specific rule groups that auto-activate based on package.json dependencies.

| Domain | Activates for | |--------|---------------| | react | React projects | | next | Next.js projects | | solid | SolidJS projects | | vue | Vue projects | | playwright | Playwright tests | | drizzle | Drizzle ORM | | qwik | Qwik projects | | project | Module graph analysis (import cycles, unresolved imports) | | types | Type inference rules (no TS compiler needed) | | test | Test-specific rules |

{
  "linter": {
    "domains": {
      "react": "recommended",
      "next": "all",
      "project": "recommended",
      "types": "recommended"
    }
  }
}

Values: "recommended" (stable rules), "all" (including nursery), "none". CLI: --only=project, --skip=test.

See references/linting-and-plugins.md for type-aware linting, suppression comments, and GritQL plugins.

Quick Reference — Assists

New category between formatter and linter. Actions without diagnostics. Import organizing moved here from linter.

{
  "assist": {
    "actions": {
      "source": {
        "organizeImports": "on",
        "useSortedKeys": { "level": "on", "options": { "groupByNesting": true } },
        "useSortedAttributes": "on",
        "noDuplicateClasses": "on"
      }
    }
  }
}

Import organizer revamp: cross-chunk sorting, import merging from same module, custom ordering, export organizing, import attribute sorting.

See references/formatting-and-languages.md for HTML formatter, embedded snippets, and framework support.

Agent Skills: Biome v2.0–v2.4 Knowledge Patch

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