medusa.json

{
    # List of all repos we want to clone. (No version number required) because we DL ALL versions
    "require": [
        "symfony/symfony-standard"
    ],
    # the folder that will hold all of the cloned repos
    "repodir":"packages",
    # the satis config file to update with all the info
    "satisconfig":"satis.json"
}

satis.json

{
    "name": "My Repository",
    "homepage": "http://packages.example.org",
    "repositories": [
    ],
    "require-all": true
}