To those who have used it: is it handy for situations where you have multiple repos that want to share a little code, but it's not worth the trouble of extracting a library, referencing it, publishing versioned releases, updating dependent repos, etc?

And instead just "sync" a code folder from one main repo (perhaps containing common domain models) to other repos?

Basically the Go philosophy that a little bit of copying is better than a lot of dependency?

Interesting. Anyone knows how this compares to using git submodules and subtrees?

I had used those to create separate repo for website artifacts while the same also remain plugged into the webapp dev repo. (Both sides remain modifiable and changes mergeable to the other side.)

Thx.

Copybara is one of those things that you should have set up yesterday.

It works great and I've seen many teams gain significant productivity when collaborating in a monorepo with public bits.

If you're even toying with an internal monorepo you owe it to yourself to give it a try.

We’re in the process of open-sourcing a few sub-projects within a monorepo, and didn’t know this existed!

I’m curious what downsides folks have experienced with this tool?

Any tips?

Nice, I built something similar ~5 years ago using nested git repos and scripts to accomplish a similar purpose of combined private and public repos.

My shell script definitely wasn't google scale tho!

Some other interesting tools in the space. Rust is using a tool called Josh to sync commits:

https://josh-project.dev

The blog post from the Rust people:

https://blog.rust-lang.org/inside-rust/2026/06/04/how-josh-h...

Meta used to have an open source tool called fbshipit. But according to its open source repo they no longer use it:

https://github.com/facebookarchive/fbshipit

Any others in this space?

That seems like a tool easily adoptable by folks engaging in dark patterns on GitHub, particularly the malware bait repos.

Cute name. (Naming is hard and important.)