common-conventional-commits

common-conventional-commits

Write all commit messages following the Conventional Commits 1.0.0 specification — producing structured, consistent commit history that enables automated tooling and clear communication.

When to use

Use this skill when:

• Writing a commit message (via git commit, interactive rebase, squash, etc.)
• Suggesting a commit message to the user
• Reviewing or correcting a commit message
• Splitting work into multiple commits and deciding how to describe each

Instructions

1. Commit message structure

Every commit message must follow this format:

<type>[(<ticket-number>)]: <description>

[optional body]

[optional footer(s)]

2. Type (required)

The first word of the commit must be a type — a noun describing the category of change. Use lowercase.

Type	When to use
feat	Adds a new feature (correlates with MINOR in SemVer)
fix	Fixes a bug (correlates with PATCH in SemVer)
docs	Documentation-only changes
style	Code style changes (formatting, whitespace) — no logic change
refactor	Code restructuring that neither fixes a bug nor adds a feature
perf	Performance improvement
test	Adding or correcting tests
build	Changes to the build system or external dependencies
ci	Changes to CI configuration files and scripts
chore	Maintenance tasks that don't modify src or test files
revert	Reverts a previous commit

Decision tree:

• Does it add new functionality the user can observe? → feat
• Does it fix broken behaviour? → fix
• Does it change how code is structured without changing behaviour? → refactor
• Does it only affect tests? → test
• Does it only affect docs? → docs
• Does it improve speed/resource usage? → perf
• Does it change build/CI config? → build or ci
• None of the above? → chore

3. Scope (optional)

A scope may be provided in parentheses after the type to indicate the section of the codebase affected. The scope must be a noun.

feat(auth): add OAuth2 login flow
fix(parser): handle empty arrays correctly
docs(readme): update installation instructions

Use scopes consistently within a project. Common scopes include module names, feature areas, or package names.

4. Ticket number (preferred)

Include the ticket number from the issue tracker as the commit scope. Extract the ticket number from the current git branch name.

Rules:

1. Run git branch --show-current to get the branch name.
2. Extract the ticket number — it is the uppercase identifier matching the pattern <PROJECT>-<number> (e.g., XODO-123, PROJ-42).
3. Use the ticket number as the scope in parentheses after the type.
4. If no ticket number can be determined from the branch name, omit it.

// Branch: feat/XODO-123-add-user-registration
feat(XODO-123): add user registration page

// Branch: fix/XODO-456-login-session-expired
fix(XODO-456): resolve login failure when session is expired

// Branch: main (no ticket number)
chore: update dependencies

5. Description (required)

The description immediately follows the colon and space after the type/scope prefix (and ticket number, if present).

Rules:

1. Use imperative mood ("add feature" not "added feature" or "adds feature").
2. Do not capitalise the first letter.
3. Do not end with a period.
4. Keep it concise — aim for under 72 characters total (type + scope + description).
5. Describe what the commit does, not how.

// Bad
feat: Added the new user registration page.
fix: This fixes the bug where users couldn't log in

// Good
feat: add user registration page
fix: resolve login failure when session is expired

6. Body (optional)

A longer body may be provided after one blank line following the description. Use the body to explain what and why, not how (the diff shows how).

• Free-form text.
• May consist of multiple paragraphs separated by blank lines.
• Use imperative mood.

fix: prevent racing of requests

Introduce a request id and a reference to latest request. Dismiss
incoming responses other than from latest request.

Remove timeouts which were used to mitigate the racing issue but are
obsolete now.

7. Footer(s) (optional)

Footers are provided one blank line after the body. Each footer consists of a token, a separator (: or #), and a value.

Common footers:

• BREAKING CHANGE: <description> — indicates a breaking API change (correlates with MAJOR in SemVer)
• Refs: #<issue-number> — references related issues
• Reviewed-by: <name> — attribution
• Co-authored-by: <name> <email> — co-authors

Footer tokens use - in place of spaces (e.g., Acked-by), except for BREAKING CHANGE which is allowed as-is.

8. Breaking changes

Breaking changes must be indicated in one of two ways (or both):

1. A ! after the type/scope, before the colon:

   feat!: remove deprecated API endpoints
   feat(api)!: change response format for /users
   

2. A BREAKING CHANGE: footer:

   feat: change response format for /users
   
   BREAKING CHANGE: the /users endpoint now returns an array instead of an object wrapper
   

If ! is used, the BREAKING CHANGE: footer may be omitted and the description serves as the breaking change explanation.

9. One logical change per commit

Each commit must represent exactly one logical change. If a commit conforms to more than one type, split it into multiple commits.

• Do not mix a bug fix with a refactor in the same commit.
• Do not mix a feature with unrelated style changes.
• This enables meaningful changelogs and clean reverts.

10. Examples

feat(XODO-123): add email notification on order completion

fix(XODO-456): resolve token refresh loop on expired sessions

docs(XODO-789): correct installation steps for Docker setup

refactor(XODO-101): extract price calculation into dedicated service

feat(XODO-202)!: change pagination response envelope

BREAKING CHANGE: list endpoints now return { data, meta } instead of a flat array

Refs: #452

revert(XODO-123): add email notification on order completion

Refs: 676104e

11. Validation checklist

Before finalising a commit message, verify:

• Starts with a valid type in lowercase.
• Scope (if present) is a noun in parentheses.
• A colon and space separate type/scope from description.
• Ticket number from branch is used as scope (if available).
• Description is in imperative mood, lowercase first letter, no trailing period.
• Total first line is ≤ 72 characters.
• Body (if present) is separated by one blank line.
• Breaking changes are indicated with ! and/or BREAKING CHANGE: footer.
• The commit represents a single logical change.

References

• Conventional Commits 1.0.0