item_type in steam community market

Question

This question is similar to the question here. But I do not want to use the link wikia page in it because it is not updated. I would like to create such a page that I can update on a regular basis automatically getting data from steam servers.

There is no way afaik in the steam community market pages that lets us see the gem value for an item that we do not own. However for an item that we do own, we can see the gem value in the steam inventory.

The request that is made to steam servers to fetch the gem value (aka goo value) for an item looks like this:

http://steamcommunity.com/auction/ajaxgetgoovalueforitemtype/?appid=[the app id]&item_type=[some number I am unable to make sense of]

Example link for:

1. A witcher 3 trading card presumably.
2. Replace 5 with 15 on the link above and it is for an emoticon or background presumably.

I would like to know if anyone has any light to shed on this matter as to what the item_type could mean here and how it corresponds to the different steam community items such as trading cards (normal), trading cards (foil), backgrounds, emoticons, etc.

Answer 1

I have written down the goo_value for the range of values [0 ; 30] of item_type for the game Spelunky (appID=239350). If a value is not shown below, then it was equal to zero.

You can notice:

• 8 fields equal to 20 (from item_type=2 to item_type=9),
• 4 fields equal to 80 (from item_type=10 to item_type=13),
• 4 fields equal to 80 (from item_type=16 to item_type=19),
• 1 field equal to 80 (for item_type=21).

I own this rare profile background, so I can check its item_type, in the Network tab of my browser, and it is equal to 21.

Moreover, on the market page, item type is mentioned only once, and seems to be linked to item rarity (rare) and item categorie (profile background).

If you check the items available for this game, you can notice that there are 8 trading cards, 5 emoticons and 4 backgrounds.

A normal card is usually worth a few gems, e.g. 20 gems, and the foil version of it 10 times more, e.g. 200 gems. The range of item_type values [2 ; 9] corresponds to the cards. With the parameter border_color=1, you get values for foil cards. Without this parameter, as shown above, you get values for normal cards.

I have already mentioned that item_type=21 corresponds to the rare background. Other item types must match the emoticons and other profile backgrounds, but I don't know the logic behind the matching.

---

As for the other game mentioned in the comment above, Fitz the Fox (appID=372830). Here is the table:

• 5 items worth 10 gems, most likely the 5 normal cards,
• 5 items worth 4 gems, which matches the number of emoticons,
• 6 items worth 10 gems, which matches the number of profile backgrounds.

Here are the items:

In summary, item_type starts at 2 with the first card, and is incremented for each other card, then come the emoticons, and finally come the profile backgrounds. This explains why item_type numbering will change from one game to another. Moreover, it can happen, as with Spelunky, that there are gaps in the numbering of items of the same categorie:

• item_type=14 and item_type=15 are gaps in the numbering of emoticons from item_type=10 to item_type=16,
• item_type=20 is a gap in the numbering of profile backgrounds from item_type=17 to item_type=21.

Additional information is provided on Arqade.