If you maintain any kind of open source library or internal API, you already know the headache you merge a simple PR, cut a new release and suddenly three downstream projects crash because you changed a config key. I built BreakGuard so we can stop doing this.

BreakGuard is a stupidly fast zero-dependency CLI (and GitHub Action) that scans your PRs and tells you exactly what you are about to break before you hit merge.

Key Features

• It tells you exactly who you broke:

Run breakguard --format html and it spits out a visual node-graph showing exactly which downstream apps are going to crash because of your PR.

• It fixes their code for you:

If you broke an API run breakguard --auto-fix-downstream. It uses AI to clone their repos, rewrite their outdated function calls to match your new API and opens PRs to fix their code automatically.

• It’s incredibly easy to use:

I hate memorizing CLI flags. If you just type breakguard in your terminal it opens an interactive arrow key wizard that holds your hand through the whole process.

• It doesn't hide in CI logs:

If you run it as a GitHub Action it doesn't just fail silently. It injects a massive Markdown report directly into the GitHub UI so reviewers can clearly see the migration notes.

No Bloat

• Zero Dependencies: Pure Python. No massive Docker containers or node modules to install.
• Understands your code: It natively parses Python, Go, and TypeScript ASTs to detect renamed functions, deleted classes and changed arguments.
• Smart Deprecations: If you actually used @deprecated tags properly it knows not to yell at you.

I built this so I could ship code faster without worrying about angry bug reports. Give it a try, it will save you a ton of headaches.