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.
UNDOCUMENTEDPOSTEmailInvitees
https://api.steampowered.com/IPartnerMeetSteamService/EmailInvitees/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
fixed64 No
UNDOCUMENTEDGetAvailability
https://api.steampowered.com/IPartnerMeetSteamService/GetAvailability/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
https://api.steampowered.com/IPartnerMeetSteamService/GetBatchPartnerEmailAndName/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32[] No
uint32[] No
UNDOCUMENTEDGetRegistrations
https://api.steampowered.com/IPartnerMeetSteamService/GetRegistrations/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
fixed64 No
https://api.steampowered.com/IPartnerMeetSteamService/GetSaleEventOrganizers/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 No
UNDOCUMENTEDPOSTTestFireEmails
https://api.steampowered.com/IPartnerMeetSteamService/TestFireEmails/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
fixed64 No
UNDOCUMENTEDUpdateRegistration
https://api.steampowered.com/IPartnerMeetSteamService/UpdateRegistration/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
fixed64 No
uint32 No
uint32 No
uint32 No
string No
bool No