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.
UNDOCUMENTEDGetSteamIDForBadgeID
https://api.steampowered.com/IDOTA2Ticket_247040/GetSteamIDForBadgeID/v1/
UNDOCUMENTEDSetSteamAccountPurchased
https://api.steampowered.com/IDOTA2Ticket_247040/SetSteamAccountPurchased/v1/
UNDOCUMENTEDSteamAccountValidForBadgeType
https://api.steampowered.com/IDOTA2Ticket_247040/SteamAccountValidForBadgeType/v1/