# biomejs/biome for Claude Code: what it does and how to install it > The biomejs/biome plugin packages 12 Claude Code skills taken from the Biome toolchain's own repository, covering parser, formatter, lint rule, type inference, and diagnostics work, plus testing, changesets, ESLint migration, doc comments, code review, and pull requests. It only helps if you are changing Biome's own Rust and JavaScript source, not for formatting or linting your own project. Canonical: https://www.flowy.sh/plugins/biomejs-biome/guide Published: 2026-10-29 Updated: 2026-10-29 Author: Flowy ## What is biomejs/biome? `biomejs/biome` is the source repository for Biome, the Rust based formatter and linter for JavaScript, TypeScript, JSX, JSON, CSS, and GraphQL (25,539 GitHub stars). Inside that same repository sits a small Claude Code plugin: 11 skills that Biome's own contributors use while working on the toolchain itself. Every one of them is scoped, in its own description, to coding agents working on the Biome codebase. This is not a plugin that formats or lints your project's code. It is procedural knowledge for people changing Biome's own parser, formatter, analyzer, or documentation, so if you are not editing Biome's source tree, there is nothing here for you to invoke. Formatting or linting your own JavaScript, TypeScript, or CSS with Biome is a separate thing entirely, done with the Biome CLI, and does not need this listing at all. ## What does biomejs/biome include? The 11 skills split into four jobs. Compiler internals: `parser-development` covers writing parsers with error recovery for a new language, including grammar definitions in Biome's own .ungram format, for JavaScript, CSS, JSON, HTML, and GraphQL. `formatter-development` covers Biome's IR based formatter, comment handling, snapshot tests, idempotency failures, and comparing output against Prettier. `lint-rule-development` scaffolds a new lint or assist rule, including code actions and configurable options. `type-inference` covers Biome's Salsa backed type system for JavaScript and TypeScript, for type aware rules and the analyzer's tracked queries. `diagnostics-development` covers writing the error messages, warnings, and advice a user sees when a rule fires. Testing and documentation: `testing-codegen` covers snapshot testing and the code generation commands a change to the parser, analyzer, or formatter needs afterward. `doc-comments` sets the house style for inline comments read by future Biome contributors, separate from the end user facing text generated from a lint rule's own doc block. Release and migration: `changeset` explains when and how to write a changeset entry so a user facing change reaches the changelog correctly. `eslint-migrate-options` is narrower than `lint-rule-development`: it applies once a Biome rule already exists and has an ESLint equivalent with configurable options, so the migration path can carry those options across instead of only mapping severity. Process: `biome-code-review` is a static, read only review of a pull request, branch, commit range, or diff against Biome's own conventions, covering lint rule placement, diagnostics quality, parser error recovery, formatter idempotency, codegen freshness, and changesets. It reports findings only, it does not edit files or run the project's build, tests, or codegen. `syntax-text-handling` covers the syntax node APIs, string extraction and embedded language handling that come up in more than one part of the codebase. ## When is biomejs/biome worth installing? This plugin only does something if you have Biome's own source checked out and are changing it: adding a lint rule, fixing the parser, or opening a pull request against the project. If you just want your own JavaScript, TypeScript, or CSS formatted and linted, installing it gives you nothing. None of its 11 components touch your project's code, they touch Biome's own Rust and JavaScript internals. Flowy indexes it as the contributor tooling it is, not as something a typical Biome user would reach for. ## How do I install biomejs/biome in Claude Code? Flowy indexes `biomejs/biome` from its public GitHub repository. The skills live in the repository's own skills directory alongside its `AGENTS.md` conventions file, so anyone can read them straight from the source before deciding whether they apply. Install from [the install card on the listing page](https://www.flowy.sh/listings/biomejs-biome#install), and the 11 skills above become available in that session. Sources: [biomejs/biome on GitHub](https://github.com/biomejs/biome), [biomejs/biome README](https://github.com/biomejs/biome#readme) ## Common questions ### What does the biomejs/biome Claude Code plugin actually do? It packages 11 skills that live inside the biomejs/biome repository and that Biome's own contributors use while working on the toolchain itself. `parser-development`, `formatter-development`, `lint-rule-development`, `type-inference`, and `diagnostics-development` cover the compiler internals, while `testing-codegen`, `changeset`, `eslint-migrate-options`, `doc-comments`, `biome-code-review` and `syntax-text-handling` cover testing, release process, and review. ### Is this plugin useful if I just want to format or lint my own code with Biome? No. None of its 11 skills touch your project's files, they are written for someone editing Biome's own Rust and JavaScript source, such as adding a lint rule or fixing the parser. Formatting or linting your own JavaScript, TypeScript, or CSS with Biome uses the separate Biome CLI and does not need this listing. ### What does the biome-code-review skill check? `biome-code-review` is a static, read only review of a pull request, branch, commit range, or diff against Biome's own conventions: lint rule placement, diagnostics quality, parser error recovery, formatter idempotency, codegen freshness, and changesets. It reports findings only, it never edits files or runs the project's build, tests, or codegen itself. ### What is the difference between lint-rule-development and eslint-migrate-options? `lint-rule-development` is for writing a brand new Biome lint or assist rule, including scaffolding, code actions, and semantic analysis. `eslint-migrate-options` is narrower: it is for a rule that already exists and has an ESLint equivalent with configurable options, so Biome's migration path can carry those options over instead of only mapping severity. ### How many components does Flowy index for biomejs/biome? Flowy indexes 11 components for biomejs/biome, and all of them are skills, there are no agents, commands, MCP servers, or hooks in this listing. They range from deep compiler work like `parser-development` and `type-inference` to process skills like `changeset` and `syntax-text-handling`. ## Related - [The listing page](https://www.flowy.sh/listings/biomejs-biome): Install command, components and repository - [Alternatives to this plugin](https://www.flowy.sh/alternatives/biomejs-biome): Peers in its category, ranked by stars - [The Claude Code plugin marketplace](https://www.flowy.sh/marketplace/plugins): How plugins install, and every plugin in the index - [superpowers for Claude Code: what it does and how to install it](https://www.flowy.sh/plugins/superpowers-flow/guide): another plugin guide - [mattpocock/skills for Claude Code: install and use](https://www.flowy.sh/plugins/matt-pocock-flow/guide): another plugin guide