interface contacts {
    enum capability {
        read-name-only,
        read,
        add,
        remove,
    }

    variant request {
        get-names,                                // requires read-names-only
        get-all-contacts,                         // requires read
        get-contact(string),                      // requires read
        add-contact(string),                      // requires add
        // tuple<node, field, value>
        add-field(tuple<string, string, string>), // requires add
        remove-contact(string),                   // requires remove
        // tuple<node, field>
        remove-field(tuple<string, string>),      // requires remove
    }

    variant response {
        get-names(list<string>),
        get-all-contacts, // JSON all-contacts dict in blob
        get-contact,      // JSON contact dict in blob
        add-contact,
        add-field,
        remove-contact,
        remove-field,
        err(string),      // any failed request will receive this response
    }
}

world contacts-sys-v0 {
    import contacts;
    include process-v0;
}