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.

Adds an item to a user's inventory

https://partner.steam-api.com/IInventoryService/AddItem/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
string Yes
uint32 Yes
uint64 Yes
bool Yes Should notify the user that the item was added to their Steam Inventory.
uint64 Yes
bool Yes If true, apply the default trade and market restriction times to this item.
bool NoIf set, treat requestid as a txnid and create this item as a result of user microtransaction purchase.

Adds a promo item to a user's inventory

https://partner.steam-api.com/IInventoryService/AddPromoItem/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
string Yes
uint32 Yes
uint64 Yes
bool Yes Should notify the user that the item was added to their Steam Inventory.
uint64 Yes
bool Yes If true, apply the default trade and market restriction times to this item.
bool NoIf set, treat requestid as a txnid and create this item as a result of user microtransaction purchase.
UNDOCUMENTEDPOSTArchiveItemDef
https://api.steampowered.com/IInventoryService/ArchiveItemDef/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 No
uint64 No
bool No

Combine two stacks of items

https://api.steampowered.com/IInventoryService/CombineItemStacks/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
uint64 Yes
uint32 Yes
uint64 Yes

Consolidate items of the given type within an user's inventory

https://partner.steam-api.com/IInventoryService/Consolidate/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
uint64 Yes
bool No

Consolidate all items within an user's inventory

https://partner.steam-api.com/IInventoryService/ConsolidateAll/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
bool Yes
UNDOCUMENTEDPOSTConsumeItem

Consume an item

https://api.steampowered.com/IInventoryService/ConsumeItem/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 No
uint64 NoItem ID to be consumed
uint32 NoAmount of the given item stack to be consumed
string No
uint64 No
uint64 NoClients may provide a unique identifier for a request to perform at most once execution. When a requestid is resubmitted, it will not cause the work to be performed again; the response message will be the current state of items affected by the original successful execution.

Craft an item in a user's inventory

https://partner.steam-api.com/IInventoryService/ExchangeItem/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
uint64 Yes
uint32 Yes
uint64 Yes

Gets a list of items that have been added to accounts

https://partner.steam-api.com/IInventoryService/GetAddItemHistory/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint32 No
uint64 Yes
uint32 Yes

Retrieves a users inventory as a big JSON blob

https://partner.steam-api.com/IInventoryService/GetInventory/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
UNDOCUMENTEDGetItemDefMeta

Get metadata about the current item definition for this game.

https://api.steampowered.com/IInventoryService/GetItemDefMeta/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 No

Get item definitions

https://partner.steam-api.com/IInventoryService/GetItemDefs/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
string Yes
uint64 Yes
uint64 Yes
uint32 NoAllow stale data to be returned for the specified number of seconds.

Get the Inventory Service price sheet

https://api.steampowered.com/IInventoryService/GetPriceSheet/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
int32 Yes
string Yes Standard short code of the requested currency (preferred)

Get the total number of available items of the given type

https://partner.steam-api.com/IInventoryService/GetQuantity/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
uint64[] Yes
bool No

Modify an item in a user's inventory

https://partner.steam-api.com/IInventoryService/ModifyItems/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
{message} Yes
uint32 Yes

Split an item stack into two stacks

https://api.steampowered.com/IInventoryService/SplitItemStack/v1/
NameValueTypeRequiredDescription
click to setstring Yes Access key
uint32 Yes
uint64 Yes
uint32 Yes
uint64 Yes