The people you choose as code owners must have write permissions for the repository. When the code owner is a team, that team must be visible and it must have write permissions, even if all the individual members of the team already have write permissions directly, through organization membership, or through another team membership.
About code owners
Code owners are automatically requested for review when someone opens a pull request that modifies code that they own. Code owners are not automatically requested to review draft pull requests. For more information about draft pull requests, see "About pull requests." When you mark a draft pull request as ready for review, code owners are automatically notified. If you convert a pull request to a draft, people who are already subscribed to notifications are not automatically unsubscribed. For more information, see "Changing the stage of a pull request."
When someone with admin or owner permissions has enabled required reviews, they also can optionally require approval from a code owner before the author can merge a pull request in the repository. For more information, see "About protected branches."
If a file has a code owner, you can see who the code owner is before you open a pull request. In the repository, you can browse to the file and hover over to see a tool tip with codeownership details.
CODEOWNERS file location
To use a CODEOWNERS file, create a new file called CODEOWNERS in the .github/, root, or docs/ directory of the repository, in the branch where you'd like to add the code owners. If CODEOWNERS files exist in more than one of those locations, GitHub will search for them in that order and use the first one it finds.
Each CODEOWNERS file assigns the code owners for a single branch in the repository. Thus, you can assign different code owners for different branches, such as @octo-org/codeowners-team for a code base on the default branch and @octocat for a GitHub Pages site on the gh-pages branch.
For code owners to receive review requests, the CODEOWNERS file must be on the base branch of the pull request. For example, if you assign @octocat as the code owner for .js files on the gh-pages branch of your repository, @octocat will receive review requests when a pull request with changes to .js files is opened between the head branch and gh-pages.
CODEOWNERS and forks
To trigger review requests, pull requests use the version of CODEOWNERS from the base branch of the pull request. The base branch is the branch that a pull request will modify if the pull request is merged.
If you create a pull request from a fork, and the base branch is in the upstream repository, then the pull request will use the CODEOWNERS file from that branch in the upstream repository. If the base branch is a branch within your fork, then the pull request will use the CODEOWNERS file from that branch in your fork, but this will only trigger review requests if the code owners are added to your fork specifically with write access.
When you view who is responsible for a file by hovering over , you will see information from the CODEOWNERS file for whichever branch in whichever repository you're looking at.
CODEOWNERS file size
CODEOWNERS files must be under 3 MB in size. A CODEOWNERS file over this limit will not be loaded, which means that code owner information is not shown and the appropriate code owners will not be requested to review changes in a pull request.
To reduce the size of your CODEOWNERS file, consider using wildcard patterns to consolidate multiple entries into a single entry.
CODEOWNERS syntax
Warning: There are some syntax rules for gitignore files that do not work in CODEOWNERS files:
- Escaping a pattern starting with
#using\so it is treated as a pattern and not a comment doesn't work - Using
!to negate a pattern doesn't work - Using
[ ]to define a character range doesn't work
A CODEOWNERS file uses a pattern that follows most of the same rules used in gitignore files. The pattern is followed by one or more GitHub usernames or team names using the standard @username or @org/team-name format. Users and teams must have explicit write access to the repository, even if the team's members already have access.
If you want to match two or more code owners with the same pattern, all the code owners must be on the same line. If the code owners are not on the same line, the pattern matches only the last mentioned code owner.
In most cases, you can also refer to a user by an email address that has been added to their account, for example user@example.com. You cannot use an email address to refer to a managed user account. For more information about managed user accounts, see "About Enterprise Managed Users" in the GitHub Enterprise Cloud documentation.
CODEOWNERS paths are case sensitive, because GitHub uses a case sensitive file system. Since CODEOWNERS are evaluated by GitHub, even systems that are case insensitive (for example, macOS) must use paths and files that are cased correctly in the CODEOWNERS file.
If any line in your CODEOWNERS file contains invalid syntax, that line will be skipped. When you navigate to the CODEOWNERS file in your repository, you can see any errors highlighted. A list of errors in a repository's CODEOWNERS file is also accessible via the API. For more information, see "REST API endpoints for repositories."
If you specify a user or team that doesn't exist or has insufficient access, a code owner will not be assigned.
Example of a CODEOWNERS file
# This is a comment.
# Each line is a file pattern followed by one or more owners.
# These owners will be the default owners for everything in
# the repo. Unless a later match takes precedence,
# @global-owner1 and @global-owner2 will be requested for
# review when someone opens a pull request.
* @global-owner1 @global-owner2
# Order is important; the last matching pattern takes the most
# precedence. When someone opens a pull request that only
# modifies JS files, only @js-owner and not the global
# owner(s) will be requested for a review.
*.js @js-owner #This is an inline comment.
# You can also use email addresses if you prefer. They'll be
# used to look up users just like we do for commit author
# emails.
*.go docs@example.com
# Teams can be specified as code owners as well. Teams should
# be identified in the format @org/team-name. Teams must have
# explicit write access to the repository. In this example,
# the octocats team in the octo-org organization owns all .txt files.
*.txt @octo-org/octocats
# In this example, @doctocat owns any files in the build/logs
# directory at the root of the repository and any of its
# subdirectories.
/build/logs/ @doctocat
# The `docs/*` pattern will match files like
# `docs/getting-started.md` but not further nested files like
# `docs/build-app/troubleshooting.md`.
docs/* docs@example.com
# In this example, @octocat owns any file in an apps directory
# anywhere in your repository.
apps/ @octocat
# In this example, @doctocat owns any file in the `/docs`
# directory in the root of your repository and any of its
# subdirectories.
/docs/ @doctocat
# In this example, any change inside the `/scripts` directory
# will require approval from @doctocat or @octocat.
/scripts/ @doctocat @octocat
# In this example, @octocat owns any file in a `/logs` directory such as
# `/build/logs`, `/scripts/logs`, and `/deeply/nested/logs`. Any changes
# in a `/logs` directory will require approval from @octocat.
**/logs @octocat
# In this example, @octocat owns any file in the `/apps`
# directory in the root of your repository except for the `/apps/github`
# subdirectory, as its owners are left empty. Without an owner, changes
# to `apps/github` can be made with the approval of any user who has
# write access to the repository.
/apps/ @octocat
/apps/github
# In this example, @octocat owns any file in the `/apps`
# directory in the root of your repository except for the `/apps/github`
# subdirectory, as this subdirectory has its own owner @doctocat
/apps/ @octocat
/apps/github @doctocat
CODEOWNERS and branch protection
Repository owners can update branch protection rules to ensure that changed code is reviewed by the owners of the changed files. Edit your branch protection rule and enable the option "Require review from Code Owners". For more information, see "About protected branches."
Note: When reviews from code owners are required, an approval from any of the owners is sufficient to meet this requirement. For example, let's say that your CODEOWNERS file contains the following line:
*.js @global-owner1 @global-owner2
This means that changes to JavaScript files could be approved by either @global-owner1 or @global-owner2, but approvals from both are not required.
To protect a repository fully against unauthorized changes, you also need to define an owner for the CODEOWNERS file itself. The most secure method is to define a CODEOWNERS file in the .github directory of the repository and define the repository owner as the owner of either the CODEOWNERS file (/.github/CODEOWNERS @owner_username) or the whole directory (/.github/ @owner_username).
As an alternative to branch protection rules, you can create rulesets. Rulesets have a few advantages over branch protection rules, such as statuses, and better discoverability without requiring admin access. You can also apply multiple rulesets at the same time. For more information, see "About rulesets."