anchor.diff:                   {[], bksw_wm_index, Config}]}].
   
   port() ->
  -    case application:get_env(bookshelf, port) of
  -        undefined ->
  -            {port, 4321};
  -        {ok, Port} ->
  -            {port, Port}
  -    end.
  +    {port, envy:get(bookshelf, port, 4321, positive_integer)}.
   
   keys() ->
  -    case application:get_env(bookshelf, keys) of
  +    case envy:get(bookshelf, keys, undefined, any) of
           undefined ->
               error({missing_config, {bookshelf, keys}});
  -        {ok, {AWSAccessKey, SecretKey}} ->
  +        {AWSAccessKey, SecretKey} ->
               {keys, {bksw_util:to_binary(AWSAccessKey),
                       bksw_util:to_binary(SecretKey)}}
       end.
   
   log_dir() ->
  -    case application:get_env(bookshelf, log_dir) of
  -        undefined ->
  -            Dir = code:priv_dir(bookshelf),
  -            {log_dir, Dir};
  -        {ok, Dir} ->
  -            {log_dir, Dir}
  -    end.
  +    {log_dir, envy:get(bookshelf, log_dir, code:priv_dir(bookshelf), any)}.
   
   reqid_header_name() ->
  -    application:get_env(bookshelf, reqid_header_name).
  +    envy:get(bookshelf, reqid_header_name, undefined, string).
   
   stream_download() ->
  -    case application:get_env(bookshelf, stream_download) of
  -        {ok, true} ->
  -            true;
  -        _ ->
  -            false
  -    end.
  +    envy:get(bookshelf, stream_download, false, boolean).
  
positive.code: %%%===================================================================
  
  ip() ->
      case application:get_env(bookshelf, ip) of
          undefined ->
              [{ip, "127.0.0.1"}];
          {ok, Ip} ->
              [{ip, Ip}]
      end.
  
  reset_dispatch() ->
      [{dispatch, Dispatch}] = dispatch(),
  
negative.code:     "/tmp/".
  -else.
  disk_store() ->
      case envy:get(bookshelf, disk_store, undefined, any) of
          undefined ->
              error({missing_config, {bookshelf, disk_store}});
          Path when is_list(Path) ->
              case ends_with($/, Path) of
                  true ->
                      Path;
  