When you want to contribute to an open source repository, you usually fork a repository so you can do your changes and later submit them via a pull request. After forking the repository on GitHub, and cloning it into your local environment - git clone <forked repository url> - the repository will have a remote URL setup, usually named origin.

You can also do this using GitHub web user interface. Check out the docs! I already mostly use this option, but it’s always useful to know the basics of doing this with git.

To use as an example, I forked anitab-org/documentation repository into my GitHub account isabelcosta/documentation. When cloning the repository I used the SSH URL of my forked repository. The commands I’ll mention will be running against the repository’s default master branch.

First, check what remote URLs your project has set up with:

git remote -v

Here the origin configuration will have the URL where your forked project is on GitHub (notice that my isabelcosta account username is there). I am also inside the root directory of the local clone of my forked repository.

~/dev/documentation > git remote -v
origin  git@github.com:isabelcosta/documentation.git (fetch)
origin  git@github.com:isabelcosta/documentation.git (push)

Now you can add the new remote repository link to your remotes. The upstream keyword is an alias for the original repository remote URL (replace <url of original repository> with this URL). You can pick another alias if you prefer.

git remote add upstream <url of original repository>

Notice that in this case, the link is pointing to anitab-org account - where the repository was originally forked from):

~/dev/documentation > git remote add upstream git@github.com:anitab-org/documentation.git

To confirm the remote repositories you have set up, the new upstream repository configuration should be there.

~/dev/documentation > git remote -v
origin  git@github.com:isabelcosta/documentation.git (fetch)
origin  git@github.com:isabelcosta/documentation.git (push)
upstream    git@github.com:anitab-org/documentation.git (fetch)
upstream    git@github.com:anitab-org/documentation.git (push)

With this setup, you can now sync your repository locally using pull/fetch code from the original repository. Here’s an example where I am pulling code from the original repository into my fork’s master branch:

~/dev/documentation > git pull upstream master
From github.com:anitab-org/documentation
 * branch            master     -> FETCH_HEAD
   85f3fdc..5854a22  master     -> upstream/master
Already up to date.

After updating my local branch, I usually also update the fork on GitHub. I push the new commits pulled from upstream to my origin forked repository (using the same master branch):

~/dev/documentation > git push origin master
Everything up-to-date

Commands summary

Check remotes: git remote -v
Add a new remote: git remote add upstream <original repository url>
Sync local repository: git pull upstream <branch>
Update remote forked repo: git push origin <branch>

You can find me on Twitter, GitHub and my personal website.

Sync fork with the original repository using git

Commands summary