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.
UNDOCUMENTEDPOSTAcceptInvite
https://api.steampowered.com/IPromotionEventInvitesService/AcceptInvite/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
uint32 No
uint32 No
string No
bool No
UNDOCUMENTEDPOSTCancelInvite
https://api.steampowered.com/IPromotionEventInvitesService/CancelInvite/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
UNDOCUMENTEDPOSTGetEmailTargets
https://api.steampowered.com/IPromotionEventInvitesService/GetEmailTargets/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 No
UNDOCUMENTEDGetInvite
https://api.steampowered.com/IPromotionEventInvitesService/GetInvite/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 NoIf provided, return only this one
uint32 Noif invite is is missing then will return all active invitations for this appid
uint32 NoIf provided, will search on packages; must match appid for routing
uint32 NoIf provided, will search on bundles; must match appid for routing
uint32 NoTo verify the partner admin has access to this partner information
string NoEmail specific to this promotion planning event
UNDOCUMENTEDPOSTResendEmailInvite
https://api.steampowered.com/IPromotionEventInvitesService/ResendEmailInvite/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 NoInvite we want to re-send
bool NoWe prefer to only notify the users explicitly added, not users with contact permissions on the associated partner ids
UNDOCUMENTEDPOSTSetInvite
https://api.steampowered.com/IPromotionEventInvitesService/SetInvite/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
CPromotionEventInvitation No
fixed64 No
uint32 No
uint32 No
uint32 No
uint32 No
int32 Noenum
uint32 No
uint32 No
uint32 No
uint32 No
uint32 No
uint32 No
uint32 No
CPromotionRequirements No
uint32 No
uint32 No
uint32 No
bool No
string[] No
string No
bool No
uint32 No
bool No
int32 Noenum
string No
string No
bool NoIf true, we will fire the email immediately; does not wait on the email to complete