This page is just a reference of all the known Steam APIs, I do not know how they work. Please do not email me with questions.
PUBLISHERPOSTRankedByPublicationOrder
https://partner.steam-api.com/ISteamPublishedItemSearch/RankedByPublicationOrder/v1/
NameValueTypeRequiredDescription
uint64 Yes SteamID of user
uint32 Yes appID of product
uint32 Yes Starting index in the result set (0 based)
uint32 Yes Number Requested
uint32 Yes Number of Tags Specified
uint32 Yes Number of User specific tags requested
bool NoWhether the user making the request is an admin for the app and can see private files
uint32 NoEPublishedFileInfoMatchingFileType, defaults to k_PFI_MatchingFileType_Items
string[] NoTag to filter result set
string[] NoA user specific tag
PUBLISHERPOSTRankedByTrend
https://partner.steam-api.com/ISteamPublishedItemSearch/RankedByTrend/v1/
NameValueTypeRequiredDescription
uint64 Yes SteamID of user
uint32 Yes appID of product
uint32 Yes Starting index in the result set (0 based)
uint32 Yes Number Requested
uint32 Yes Number of Tags Specified
uint32 Yes Number of User specific tags requested
bool NoWhether the user making the request is an admin for the app and can see private files
uint32 NoEPublishedFileInfoMatchingFileType, defaults to k_PFI_MatchingFileType_Items
uint32 No[1,7] number of days for the trend period, including today
string[] NoTag to filter result set
string[] NoA user specific tag
PUBLISHERPOSTRankedByVote
https://partner.steam-api.com/ISteamPublishedItemSearch/RankedByVote/v1/
NameValueTypeRequiredDescription
uint64 Yes SteamID of user
uint32 Yes appID of product
uint32 Yes Starting index in the result set (0 based)
uint32 Yes Number Requested
uint32 Yes Number of Tags Specified
uint32 Yes Number of User specific tags requested
bool NoWhether the user making the request is an admin for the app and can see private files
uint32 NoEPublishedFileInfoMatchingFileType, defaults to k_PFI_MatchingFileType_Items
string[] NoTag to filter result set
string[] NoA user specific tag
PUBLISHERPOSTResultSetSummary
https://partner.steam-api.com/ISteamPublishedItemSearch/ResultSetSummary/v1/
NameValueTypeRequiredDescription
uint64 Yes SteamID of user
uint64 Yes appID relevant to all subsequent tags
uint32 Yes Number of Tags Specified
uint32 Yes Number of User specific tags requested
bool NoWhether the user making the request is an admin for the app and can see private files
uint32 NoEPublishedFileInfoMatchingFileType, defaults to k_PFI_MatchingFileType_Items
string[] NoTag to filter result set
string[] NoA user specific tag