Define and publish Steam Inventory Service item definitions with tradable and marketable flags
domain: steamworks · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
In the Steamworks partner portal, navigate to your app's Economy section and open the Item Definitions editor
Create an item definition JSON object with required fields: itemdefid (integer), type (e.g. 'item'), name, and description; set tradable and marketable booleans to control Steam trading and Market eligibility
Set the icon_url and icon_url_large fields pointing to hosted image URLs; images must meet Steam's minimum resolution requirements
Use the pricecat or price fields to configure store prices if you want items sold via the Steam Item Store
Publish the schema via the partner portal and call ISteamInventory::RequestEligiblePromoItemDefinitionsIDs on the client to verify items appear; use SteamGameServer_Init on dedicated servers to access inventory APIs
Known gotchas
itemdefid values must remain stable once published; changing an itemdefid effectively creates a new item type and orphans existing player inventory entries with the old ID
tradable:false items can still appear in a player's inventory but cannot be sent in trade offers or listed on the Community Market; set this intentionally for season-pass or account-bound items
Item definitions are cached by Steam; after schema updates allow several minutes for the change to propagate before testing on the client
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