AddPromoItem() / AddPromoItems() are restricted versions of GrantPromoItems(). Instead of

scanning for all eligible promotional items, the check is restricted to a single item

definition or set of item definitions. This can be useful if your game has custom UI for

showing a specific promo item to the user.

Returns true if the result belongs to the target steam ID, false if the

result does not. This is important when using DeserializeResult, to verify

that a remote player is not pretending to have a different user's inventory.

ConsumeItem() removes items from the inventory, permanently. They cannot be recovered.

Not for the faint of heart - if your game implements item removal at all, a high-friction

UI confirmation process is highly recommended.

Deserializes a result set and verifies the signature bytes. Returns false

if bRequireFullOnlineVerify is set but Steam is running in Offline mode.

Otherwise returns true and then delivers error codes via GetResultStatus.

The bRESERVED_MUST_BE_FALSE flag is reserved for future use and should not

be set to true by your game at this time.

DeserializeResult has a potential soft-failure mode where the handle status

is set to k_EResultExpired. GetResultItems() still succeeds in this mode.

The "expired" result could indicate that the data may be out of date - not

just due to timed expiration (one hour), but also because one of the items

in the result set may have been traded or consumed since the result set was

generated. You could compare the timestamp from GetResultTimestamp() to

ISteamUtils::GetServerRealTime() to determine how old the data is. You could

simply ignore the "expired" result code and continue as normal, or you

could challenge the player with expired data to send an updated result set.

Destroys a result handle and frees all associated memory.

ExchangeItems() is an atomic combination of item generation and consumption.

It can be used to implement crafting recipes or transmutations, or items which unpack

themselves into other items (e.g., a chest).

Exchange recipes are defined in the ItemDef, and explicitly list the required item

types and resulting generated type.

Exchange recipes are evaluated atomically by the Inventory Service; if the supplied

components do not match the recipe, or do not contain sufficient quantity, the

exchange will fail.

INVENTORY ASYNC MODIFICATION

GenerateItems() creates one or more items and then generates a SteamInventoryCallback_t

notification with a matching nCallbackContext parameter. This API is only intended

for prototyping - it is only usable by Steam accounts that belong to the publisher group

for your game.

If punArrayQuantity is not NULL, it should be the same length as pArrayItems and should

describe the quantity of each item to generate.

INVENTORY ASYNC QUERY

Captures the entire state of the current user's Steam inventory.

You must call DestroyResult on this handle when you are done with it.

Returns false and sets *pResultHandle to zero if inventory is unavailable.

Note: calls to this function are subject to rate limits and may return

cached results if called too frequently. It is suggested that you call

this function only when you are about to display the user's full inventory,

or if you expect that the inventory may have changed.

After handling a SteamInventoryEligiblePromoItemDefIDs_t call result, use this

function to pull out the list of item definition ids that the user can be

manually granted via the AddPromoItems() call.

GetItemDefinitionIDs returns the set of all defined item definition IDs (which are

defined via Steamworks configuration, and not necessarily contiguous integers).

If pItemDefIDs is null, the call will return true and *punItemDefIDsArraySize will

contain the total size necessary for a subsequent call. Otherwise, the call will

return false if and only if there is not enough space in the output array.

GetItemDefinitionProperty returns a string property from a given item definition.

Note that some properties (for example, "name") may be localized and will depend

on the current Steam language settings (see ISteamApps::GetCurrentGameLanguage).

Property names are always composed of ASCII letters, numbers, and/or underscores.

Pass a NULL pointer for pchPropertyName to get a comma - separated list of available

property names. If pchValueBuffer is NULL, *punValueBufferSize will contain the

suggested buffer size. Otherwise it will be the number of bytes actually copied

to pchValueBuffer. If the results do not fit in the given buffer, partial

results may be copied.

Captures the state of a subset of the current user's Steam inventory,

identified by an array of item instance IDs. The results from this call

can be serialized and passed to other players to "prove" that the current

user owns specific items, without exposing the user's entire inventory.

For example, you could call GetItemsByID with the IDs of the user's

currently equipped cosmetic items and serialize this to a buffer, and

then transmit this buffer to other players upon joining a game.

In combination with GetResultItems, you can use GetResultItemProperty to retrieve

dynamic string properties for a given item returned in the result set.

Property names are always composed of ASCII letters, numbers, and/or underscores.

Pass a NULL pointer for pchPropertyName to get a comma - separated list of available

property names.

If pchValueBuffer is NULL, *punValueBufferSize will contain the

suggested buffer size. Otherwise it will be the number of bytes actually copied

to pchValueBuffer. If the results do not fit in the given buffer, partial

results may be copied.

Copies the contents of a result set into a flat array. The specific

contents of the result set depend on which query which was used.

INVENTORY ASYNC RESULT MANAGEMENT

Asynchronous inventory queries always output a result handle which can be used with

GetResultStatus, GetResultItems, etc. A SteamInventoryResultReady_t callback will

be triggered when the asynchronous result becomes ready (or fails).

Find out the status of an asynchronous inventory result handle. Possible values:

k_EResultPending - still in progress

k_EResultOK - done, result ready

k_EResultExpired - done, result ready, maybe out of date (see DeserializeResult)

k_EResultInvalidParam - ERROR: invalid API call parameters

k_EResultServiceUnavailable - ERROR: service temporarily down, you may retry later

k_EResultLimitExceeded - ERROR: operation would exceed per-user inventory limits

k_EResultFail - ERROR: unknown / generic error

Returns the server time at which the result was generated. Compare against

the value of IClientUtils::GetServerRealTime() to determine age.

GrantPromoItems() checks the list of promotional items for which the user may be eligible

and grants the items (one time only). On success, the result set will include items which

were granted, if any. If no items were granted because the user isn't eligible for any

promotions, this is still considered a success.

ITEM DEFINITIONS

Item definitions are a mapping of "definition IDs" (integers between 1 and 1000000)

to a set of string properties. Some of these properties are required to display items

on the Steam community web site. Other properties can be defined by applications.

Use of these functions is optional; there is no reason to call LoadItemDefinitions

if your game hardcodes the numeric definition IDs (eg, purple face mask = 20, blue

weapon mod = 55) and does not allow for adding new item types without a client patch.

LoadItemDefinitions triggers the automatic load and refresh of item definitions.

Every time new item definitions are available (eg, from the dynamic addition of new

item types while players are still in-game), a SteamInventoryDefinitionUpdate_t

callback will be fired.

Request the list of "eligible" promo items that can be manually granted to the given

user. These are promo items of type "manual" that won't be granted automatically.

An example usage of this is an item that becomes available every week.

TIMED DROPS AND PLAYTIME CREDIT

Deprecated. Calling this method is not required for proper playtime accounting.

RESULT SERIALIZATION AND AUTHENTICATION

Serialized result sets contain a short signature which can't be forged

or replayed across different game sessions. A result set can be serialized

on the local client, transmitted to other players via your game networking,

and deserialized by the remote players. This is a secure way of preventing

hackers from lying about posessing rare/high-value items.

Serializes a result set with signature bytes to an output buffer. Pass

NULL as an output buffer to get the required size via punOutBufferSize.

The size of a serialized result depends on the number items which are being

serialized. When securely transmitting items to other players, it is

recommended to use "GetItemsByID" first to create a minimal result set.

Results have a built-in timestamp which will be considered "expired" after

an hour has elapsed. See DeserializeResult for expiration handling.

IN-GAME TRADING

TradeItems() implements limited in-game trading of items, if you prefer not to use

the overlay or an in-game web browser to perform Steam Trading through the website.

You should implement a UI where both players can see and agree to a trade, and then

each client should call TradeItems simultaneously (+/- 5 seconds) with matching

(but reversed) parameters. The result is the same as if both players performed a

Steam Trading transaction through the web. Each player will get an inventory result

confirming the removal or quantity changes of the items given away, and the new

item instance id numbers and quantities of the received items.

(Note: new item instance IDs are generated whenever an item changes ownership.)

TransferItemQuantity() is intended for use with items which are "stackable" (can have

quantity greater than one). It can be used to split a stack into two, or to transfer

quantity from one stack into another stack of identical items. To split one stack into

two, pass k_SteamItemInstanceIDInvalid for itemIdDest and a new item will be generated.

Playtime credit must be consumed and turned into item drops by your game. Only item

definitions which are marked as "playtime item generators" can be spawned. The call

will return an empty result set if there is not enough playtime credit for a drop.

Your game should call TriggerItemDrop at an appropriate time for the user to receive

new items, such as between rounds or while the player is dead. Note that players who

hack their clients could modify the value of "dropListDefinition", so do not use it

to directly control rarity.

See your Steamworks configuration to set playtime drop rates for individual itemdefs.

The client library will suppress too-frequent calls to this method.