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.
https://api.steampowered.com/INewsService/ConvertHTMLToBBCode/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
string No
bool Noby default, newlines are all removed and then <p> and <br> will become newlines
https://api.steampowered.com/INewsService/GetBatchPublishedPartnerEvent/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
fixed64 NoGid of news source
uint32 No
uint32 No
https://api.steampowered.com/INewsService/GetNewsFeedByRepublishClan/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 NoThe clan account ID which we are republishing to
https://api.steampowered.com/INewsService/PreviewPartnerEvents/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
string No
uint32 No
UNDOCUMENTEDPOSTPublishPartnerEvent
https://api.steampowered.com/INewsService/PublishPartnerEvent/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
CNewsFeedPostDef NoThe post user wants to publish that was previously received from Preview method
fixed64 No
fixed64 No
string No
string No
string No
uint32 No
string No
bool No
bool No
string No
uint32[] No
int32 Noenum
bool No
bool No
string No
string No
string No
bool NoIf true, then create the partner event in draft mode