_This specification is inspired by and supersedes the [Brainclements commit message format](https://gist.github.com/brianclements/841ea7bffdb01346392c)._
We have very precise rules over how our Git commit messages must be formatted.
This format leads to **easier to read commit history**.
Each commit message consists of a **header**, a **body**, and a **footer**.
```
<header>
<BLANKLINE>
<body>
<BLANKLINE>
<footer>
```
The `header` is mandatory and must conform to the [Commit Message Header](#commit-header) format.
The `body` is mandatory for all commits except for those of type "docs".
When the body is present it must be at least 20 characters long and must conform to the [Commit Message Body](#commit-body) format.
The `footer` is optional. The [Commit Message Footer](#commit-footer) format describes what the footer is used for and the structure it must have.
There are currently a few exceptions to the "use package name" rule:
- none/empty string: useful for `test` and `refactor` changes that are done across all packages (e.g. `test: add missing unit tests`) and for docs changes that are not related to a specific package (e.g. `docs: fix typo in tutorial`).
##### Summary
Use the summary field to provide a succinct description of the change:
- use the imperative, present tense: "change" not "changed" nor "changes"
- don't capitalize the first letter
- no dot (.) at the end
#### <a name="commit-body"></a>Commit Message Body
Just as in the summary, use the imperative, present tense: "fix" not "fixed" nor "fixes".
Explain the motivation for the change in the commit message body. This commit message should explain _why_ you are making the change.
You can include a comparison of the previous behavior with the new behavior in order to illustrate the impact of the change.