All resource groups and resources exist within subscriptions. These operation enable you get information about your subscriptions and tenants. A tenant is a dedicated instance of Azure Active Directory (Azure AD) for your organization.
curl \ -H "Authorization: Bearer $ACCESS_TOKEN" \ /tenants
curl \ -H "Authorization: Bearer $ACCESS_TOKEN" \ /subscriptions
curl \
-H "Authorization: Bearer $ACCESS_TOKEN" \
/subscriptions/{subscriptionId}