# get `repo` level access to the private repo for the organization/user
# get OAuth token through Authorization API
https://developer.github.com/v3/oauth/#oauth-authorizations-api
# now use the token in the URL, but don't `clone`,
# clone would save the token to disk and the token should
# be treated like passwords
mkdir foo
cd foo
git init
git pull https://<token>@github.com/username/bar.git

Sources

• Easier builds and deployments using Git over HTTPS and OAuth