Conventional Commits: machine-readable commit types

What it is

Conventional Commits is a lightweight convention for commit messages: type(optional scope)!: description, followed by an optional body and footers. The specification defines fix for bug fixes and feat for new features; other types such as docs, refactor, test or chore are permitted but not standardised by the specification itself.

Why it matters

The convention gives tooling a reliable signal. A fix maps to a patch release, a feat to a minor release, and a BREAKING CHANGE: footer or a ! after the type maps to a major release under Semantic Versioning. Changelogs, release notes and version bumps can then be generated from history instead of being written by hand.

How to apply

• Agree on the allowed types and scopes and keep the list short.
• Put the human explanation in the body, as any good commit message would; the prefix only classifies.
• Mark breaking changes explicitly and describe the migration in the footer.
• Enforce the shape with a commit hook or a CI check only after the team has practised it for a while.

Pitfalls

Typed prefixes do not make a message good; "fix: fix" is still empty. Squash merges must preserve or rewrite the prefix, otherwise the generated changelog is wrong. Scopes that mirror the directory tree become noise in small repositories.