actions/labeler

Pull Request Labeler is a GitHub Action that automatically applies labels to pull requests based on file path patterns or branch names.

The tool solves the problem of manually labeling pull requests by reading a configuration file that defines matching rules. Users create a `.github/labeler.yml` file specifying labels and their corresponding match conditions. The action evaluates these conditions against the files changed in a pull request or the names of the base and head branches, then applies matching labels automatically. The matching system supports glob patterns for file paths and regular expressions for branch names, with logical operators to combine multiple conditions using `any` (OR logic) and `all` (AND logic).

Teams should adopt this tool if they want to enforce consistent labeling workflows without manual intervention. It suits projects of any size that use labels for triage, automation, or organization. The action integrates directly into GitHub's workflow system and requires only a configuration file in the repository.

The project has undergone significant evolution in its runtime and internal architecture. It migrated to ESM internally to support the latest GitHub Actions packages while maintaining backward compatibility with existing configurations. The action was upgraded from Node.js 20 to Node.js 24, requiring runners on version 2.327.1 or later. The configuration file structure was substantially redesigned in version 5 to support branch-based matching alongside file-based matching, making the tool more flexible but requiring users to update existing configurations. The default behavior for matching dotfiles changed to include paths starting with a dot by default. A bug fix corrected how the sync-labels input was being read.