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.
UNDOCUMENTEDGetParticipationDetails
https://api.steampowered.com/IDOTA2AutomatedTourney_247040/GetParticipationDetails/v1/
UNDOCUMENTEDGetPlayerHistory
https://api.steampowered.com/IDOTA2AutomatedTourney_247040/GetPlayerHistory/v1/
UNDOCUMENTEDGetTournamentDetails
https://api.steampowered.com/IDOTA2AutomatedTourney_247040/GetTournamentDetails/v1/