Varlock Releases Bumpy, a File-Based Versioning Tool for Monorepos

Introduction to Bumpy

Varlock has launched Bumpy, a version management and changelog tool for monorepos. Positioned as a successor to Changesets, Bumpy aims to resolve over 120 open issues identified in its predecessor. The project, initially unveiled in April 2026, is now available under the @varlock/bumpy package.

Workflow and Core Features

Bumpy maintains a workflow similar to Changesets, where contributors create markdown 'bump files' in a .bumpy/ directory. These files specify package release levels and changelog descriptions, are reviewable in PR diffs, and are consolidated into a release PR by CI. The tool supports workspace: and catalog: protocols across npm, pnpm, Yarn, and Bun.

It also includes per-package custom publish commands for various targets like VS Code extensions, Docker images, or JSR, and a three-phase dependency propagation algorithm for managing peer dependency updates.

CI and Prerelease Improvements

The CI process in Bumpy is streamlined, utilizing two commands, bumpy ci check and bumpy ci release, directly within standard GitHub Actions workflows without requiring a GitHub App or separate action repository. Version 1.14 introduced branch-based prerelease channels, where prerelease versions are generated at publish time and not committed to Git, addressing complexities found in Changesets' prerelease mode.

AI Integration and Adoption

Bumpy integrates AI through an agent skill that teaches large language models to analyze Git changes, identify affected packages, and generate bump files via bumpy add. This skill can be installed through the Vercel Labs skills CLI, GitHub CLI, or as a Claude Code plugin. The project was developed with AI assistance and is currently used for releasing Varlock and over 25 related libraries and plugins.

Getting Started

Users can get started with Bumpy by installing it and running an init command, which automatically migrates existing Changesets projects. The installation command is bun add -d @varlock/bumpy followed by bunx bumpy init.