question

Hi, I have checked the PlayFab Docs and reproduced your issue, it seems that Trading APIs are Client APIs, it’s called by players who want to make a trade with others. For example, there are three parameters in the OpenTrade API request body:

• AllowedPlayerIds: Players who are allowed to accept the trade. If null, the trade may be accepted by any player. If empty, the trade may not be accepted by any player
• OfferedInventoryInstanceIds: Player inventory items offered for trade. If not set, the trade is effectively a gift request
• RequestedCatalogItemIds: Catalog items accepted for the trade. If not set, the trade is effectively a gift.

As I understand it, the player who wants to make a trade is not listed in the parameters field. It indicates that Trading APIs are applicable from the Client’s side, not in the CloudScript, you may need to open a new trade and handle it on client’s side.

Here is the doc you may want to refer: https://docs.microsoft.com/en-us/rest/api/playfab/client/trading?view=playfab-rest