pr-size-labeler is an open-source GitHub App written in Go that automatically applies size labels (XS through XXL) to pull requests based on effective code change size. It excludes generated files via .gitattributes, supports custom label thresholds and comments via .github/labels.yml, and offers proactive backfill relabeling and startup recovery for missed webhook deliveries. Unlike GitHub Actions-based alternatives, it runs as a centralized service requiring no per-repo workflow files, consumes no Actions minutes, and can be self-hosted or deployed to Hugging Face Spaces.
Table of contents
Why use this instead of a GitHub Action?ExampleWhat it doesDefault labelsRepository configurationQuick startDeploymentReleasesContributingAgent-oriented developmentLicenseSort: