defaultFilterParam <- lookupGetParam "filter"
    let defaultFilterJson = (maybe Nothing (decode . LBS.fromChunks . (:[]) . encodeUtf8) defaultFilterParam) :: Maybe [FS.Filter]
    defaultSortParam <- lookupGetParam "sort"
    let defaultSortJson = (maybe Nothing (decode . LBS.fromChunks . (:[]) . encodeUtf8) defaultSortParam) :: Maybe [FS.Sort]