Purpose
Use this skill when a PR introduces user-facing changes that require a changeset. Changesets drive CHANGELOG generation and release automation. Internal-only changes (refactors with no user-visible effect) do not need changesets.
Create a Changeset
Do not create changeset files manually. Use:
just new-changeset-emptyThe command will create a file in .changeset/. Edit it directly to add detail.
Note that the file will *not* be literally empty. It will have this content:
---
---Do not simply append to the changeset description below the existing content, which creates an invalid changeset.
Requirespnpm— runpnpm ifrom repo root first.
Choose the Correct Change Type
patch— Bug fixes.minor— New features. PR must target thenextbranch.major— Breaking user API changes. PR must target thenextbranch. These are rare and strictly controlled.
Refer to the versioning page when unsure.
Changeset Format
---
"@biomejs/biome": patch
---
Description here.If you need headers inside the description, use #### or ##### only. Other header levels break the CHANGELOG tooling.
Writing Guidelines
General Rules
- Write about user-facing changes only. No changeset needed for pure refactoring. Describe how the change affects the user.
- Be concise and clear — 1 to 3 sentences. Longer entries signal to users that the change deserves attention.
- Past tense for what you did: "Added", "Fixed", "Changed".
- Present tense for Biome behavior: "Biome now supports...", "The rule now detects...".
- End every sentence with a full stop (
.).
Bug Fixes
Start with a link to the issue:
Fixed [#4444](https://github.com/biomejs/biome/issues/4444): [`useOptionalChain`](https://biomejs.dev/linter/rules/use-optional-chain/) now detects negated logical OR chains.New Lint Rules
Show an example of an invalid case. Use inline code for simple things, a code block for complex ones:
Added a new nursery rule [`noDuplicateSelectors`](https://biomejs.dev/linter/rules/no-duplicate-selectors/), that disallows duplicate selector lists within the same at-rule context.
For example, the following snippet triggers the rule:
` ` `css
.foo {}
.foo {}
` ` `Changes to Existing Rules
Clearly show what is now invalid that was not before (or vice versa). Show both sides if helpful:
Fixed [#7211](https://github.com/biomejs/biome/issues/7211): [`useOptionalChain`](https://biomejs.dev/linter/rules/use-optional-chain/) now detects negated logical OR chains. The following code is now considered invalid:
` ` `js
!foo || !foo.bar
` ` `Formatter Changes
Show the formatting diff:
Changed formatting of arrow function parameters. Example:
` ` `diff
- const fn = ( a, b ) => {};
+ const fn = (a, b) => {};
` ` `Parser Changes
Brief inline example of what can now be parsed:
Added support for parsing `using` declarations in JavaScript.Use a code block if multiline clarity helps.
Linking Rules and Assists
Always link to the website, even if the page does not exist yet (it will after merge):
- Rules: `
[useConst](https://biomejs.dev/linter/rules/use-const/)` - Assists: `
[organizeImports](https://biomejs.dev/assist/actions/organize-imports/)`
Tips
- Create the changeset before opening the PR; you can edit it after.
- Look at existing files in
.changeset/or recentCHANGELOG.mdentries for reference. - One changeset per PR is typical. Multiple changesets are allowed if the PR addresses multiple, distinct bugs.
References
- Contribution guide:
CONTRIBUTING.mdsection "Changelog" - Versioning policy: https://biomejs.dev/internals/versioning/
- Changesets documentation: https://github.com/changesets/changesets