When you have a few repositories, keeping track of dependencies between them is pretty straightforward.

But what happens when you have 50, 100, or even 200 repositories?

Imagine you're about to update a shared Terraform module. Before merging, you want to know:

Which repositories are using it?

Which versions are they using?

Are there other repositories that depend on those repositories?

Who might be affected by the change?

GitHub search can help, but manually piecing together all those relationships gets tedious pretty quickly.

I wanted a way to answer those questions without setting up a service or maintaining a separate dependency catalog.

So I built RippleMap , an open-source CLI that automatically maps dependencies across repositories.

Testing it on 163 real Terraform repositories

Instead of just testing it on a few example projects, I ran RippleMap against Cloud Posse's public Terraform module repositories.

The scan covered 163 repositories and identified 467 dependency links .

Two findings…