PullPreview is a GitHub Action implemented in Go that provisions ephemeral preview environments for pull requests. It manages cloud instances (AWS Lightsail or Hetzner), installs Docker or Kubernetes (k3s), and deploys applications using Docker Compose or Helm. The action integrates deeply with GitHub PR workflows: it reacts to labels, synchronizes SSH keys from repository collaborators, updates PR comments with deployment status and preview URLs, and performs scheduled cleanup of dangling instances. The codebase is organized around a provider abstraction pattern, with concrete implementations for Lightsail and Hetzner that share common orchestration logic for instance lifecycle, SSH access, and deployment. It is a self-contained CLI binary that runs as a composite action step, bundling all dependencies into a single executable.