Jump to content

Most Liked Content

#889 Identifying Steam Items

Posted by Dr. McKay on 20 May 2016 - 12:40 AM

Sometimes it can be a little confusing to identify a specific item in the Steam economy. There are several different types of IDs present in one particular item, and a lot of vague terminology. This guide aims to clear all that up for you.

For starters, the "official" term for a Steam item is an asset. When I say a "Steam item", I mean a particular copy of an item. I'm not referring to the item's definition, name, image, or anything. I'm referring to a specific, unique copy of the item.

In a general sense, every item on Steam must be owned by an app. An "app" is a game, software, or whatever on Steam. Every app has its own unique AppID. You can find a particular game's AppID by going to its store page or community hub and looking at the URL. For example, TF2's AppID is 440 so TF2's store page can be found at http://store.steampowered.com/app/440. CS:GO's is 730, Dota 2's is 570, and so on. Note that Steam Community items, Steam gifts, and other "Steam" items are owned by the "Steam" app, which has AppID 753. To identify an item, you'll need the AppID of the game which owns it.

Of course, the AppID alone isn't enough. You also need two other IDs. Have you ever noticed how some games have multiple inventories, which appear in a drop-down list? An example is the Steam inventory, which has sub-inventories for "Community", "Gifts", "Coupons", etc. These "sub-inventories" are called contexts, and each context has its own context ID. If a game doesn't have a drop-down menu to select a context, that doesn't mean that it's without contexts. That only means that it has one single visible context. That single context still has an ID. For all current Valve games, the context ID for the publicly-visible context is 2.

Context IDs can be a bit tricky. It's entirely up to the game's developer to determine how they work. For example, Valve games take the "single shared inventory" model in which there's one context ID which is shared by everyone. Under this model, an item belongs to one particular context and never leaves that context. Consequently, the item's context ID never changes. It is, however, possible for game developers to create contexts in any way they choose. For example, Spiral Knights uses the "per-character inventory" model in which everyone who plays the game has their own context IDs for their characters. Creating a new character creates a new context ID. This means that when an item is traded between users, its context ID will change as it moved out of a particular character's inventory.

Those are the two different types of "containers" in the Steam economy. Apps own contexts, and contexts own assets. Every asset on Steam has, in addition to its AppID and context ID, an asset ID which is guaranteed to be unique inside of a given AppID+ContextID combination. Notice that this means that asset IDs are not unique across all of Steam. They aren't even unique across a particular app. They are only unique inside of a given context. For example, there could be two items with asset ID 1 in the same game, as long as they have different context IDs. An item's asset ID may be referred to as "assetid" or just plain "id".

Context IDs and asset IDs are assigned by the game developer and can follow any pattern. They can change when traded or not. They may both be up to 64 bits in size. Consequently, Steam returns them (like all other 64-bit values) in JSON as strings.

Still following? All of what we've learned so far leads us to this conclusion: in order to uniquely identify an item, you need its AppID, its context ID, and its asset ID. Once you have these three things, only then can you uniquely identify it. In fact, this is how you link to a particular item in a user's inventory: steamcommunity.com/profiles/steamid/inventory#appid_contextid_assetid. Here's an example: https://steamcommuni...440_2_134161610

What on Earth are these "classid" and "instanceid" values though??
The observant reader may have noticed that there are two more IDs attached to a particular item which I haven't mentioned. These are the "classid" and "instanceid". These IDs are used to map an asset to its description.

What's a description? A description is what you need in order to actually display an item. An item's description contains its name, image, color, market_name, whether it's tradable or not, whether it's marketable or not, and more. There are many endpoints on Steam which return JSON objects representing assets that only contain the asset's AppID, context ID, asset ID, classid, instanceid, and amount. An item's amount is how big of a stack it is. Unstackable items always have an amount of 1. Stackable items (such as Steam gems) may have a larger amount. Stacked items always have the same asset ID.

What's the difference between a classid and an instanceid? Well in a nutshell, a classid "owns" an instanceid. The classid is all you need to get a general overview of an item. For example, items with the same classid will pretty much always have the same name and image. The instanceid allows you to get finer-tuned details such as how many kills are on a strange/StatTrak weapon, or custom names/descriptions.

You can turn a classid/instanceid pair into a description using the GetAssetClassInfo WebAPI method. Notice that the instanceid is actually optional: if you only have a classid that's fine, you just won't get finer details for the item.

Do note that it's possible for a game developer to flush Steam's asset cache entirely, which would change the classid/instanceid of every item. As of the time of this posting, I'm unaware of this ever having been done.

Name? Market Name? Market Hash Name? Halp?
Every asset on Steam has a name. Period. Without a name, there's nothing to show in your inventory. The item's name is the... (wait for it...) name property of its description (shocking, I know). The item's name may be localized if the game's developer has set it up to be.

Every marketable item also has a "market name". This name may be the same as, or different from the item's regular name. The item's market name is the market_name property of its description. This is the name that's displayed in the Steam Community Market when the item is up for sale. Why the distinction? There are some items which have value-affecting data that isn't in their name. For example, CS:GO skins have 5 different tiers of "wear", which isn't in their names. The wear tier is appended to each skin's market name however, so that the different tiers of wear are separated in the market. The market name may be localized or not, and may not exist at all if the item isn't marketable. It's up to the game's developer.

Finally, every marketable item also has a "market hash name", available under the market_hash_name property. This name is supposed to be the English version of the item's market name, but in practice it may vary. For example, Steam Community items prepend the AppID of the originating app to each item's market hash name, but not to the market name. The market hash name is never localized, and may not exist if the item isn't marketable. Again, it's up to the game's developer. You can view the Community Market listings for any marketable item using this URL formula: steamcommunity.com/market/listings/appid/market_hash_name. Here's an example: https://steamcommuni...upply Crate Key

Note that the Community Market has no concept of contexts. Consequently, market [hash] names are unique for a particular "class" of items per-app (and by extension per-context). This means that for marketable items, two items with identical market hash names will be worth roughly the same (with some exceptions, like unusual TF2 items).

Ask below. I'm happy to help!

  • Mole, Andrew, trzyrazyzero and 3 others like this

#734 Trading and Escrow -- Mobile Trade Confirmations

Posted by Dr. McKay on 27 April 2016 - 03:19 PM

As of December 2015, all users who are losing items in a trade must have the Steam Guard Mobile Authenticator enabled, or else the trade will be held for three fifteen days. It's also no longer possible to opt-out of trade confirmations.


This means that effectively, all trading bots need a mobile authenticator and need to accept mobile trade confirmations. You don't need an actual physical phone to act as your mobile authenticator, however. Through the efforts of myself and others, you can emulate a mobile authenticator right from node.js, and also accept trade confirmations.


Enabling a Mobile Authenticator


The Steam Guard Mobile Authenticator provides two-factor authentication security (hereinafter "2FA") for your account, which is more secure than standard email-based Steam Guard. This is done using a "shared secret" which is known to both the Steam servers and to your authenticator. Both sides run this secret through an algorithm along with the current time, which produces a 5-character alphanumeric code. This code is only valid for 30 seconds, and can only be used once. Attempts to reuse a 2FA code (either through the Steam Client or by logging in on steamcommunity.com) will treat the code as incorrect and reject it. For this reason, you can't login more frequently than once in a 30-second period.


Enabling 2FA is a three-step process.

  1. Link and verify a phone number with your Steam account. You can do this manually from your account page, or programmatically using node-steamstore.
  2. Call enableTwoFactor using either node-steam-user or node-steamcommunity. If successful, this will return an object containing a bunch of properties. You should save this entire object. You can call JSON.stringify on it safely to turn it into a string. You'll need the revocation_code in the future if you ever want to disable 2FA. At this stage, 2FA isn't enabled yet. Steam will send you an SMS containing a code which you'll need in step 3.
  3. Call finalizeTwoFactor using either node-steam-user or node-steamcommunity. You will need the value of the shared_secret property from the object returned in step 2, and the numeric activation code from your SMS. If successful, your Steam account now has 2FA.

Logging in With a Mobile Authenticator


If you have 2FA enabled, then for every login you will need to provide a twoFactorCode (unless you're logging in with node-steam-user using a loginKey). You can generate this code using node-steam-totp and your shared_secret which you obtained (and should have saved) when you enabled 2FA.


Mobile-Confirming Trades


You are now required to confirm all trades in which you lose items. If you don't have 2FA enabled, then these confirmations will go to your email and the trades will be held for fifteen days. If you do have 2FA enabled, then the confirmations must be accepted through Steam's mobile confirmation interface. You can also accept mobile confirmations through node.js.


node-steam-tradeoffer-manager doesn't have anything built-in to accept mobile confirmations. This is because mobile confirmations encompass more than just trades -- market listings also require confirmation, and potentially other things in the future.


node-steamcommunity can accept your confirmations for you. In order to accept mobile confirmations, you will need the identity_secret (not the shared_secret used for login) from when you enabled 2FA. The best way to do this is to call acceptConfirmationForObject right after each trade offer you send/accept or market listing you create.

  • Andreabum and AndrewRoni like this

#5497 i thought offer.accept do not work now

Posted by Eradicate on 16 April 2018 - 02:59 PM

Whenever you get an offer you need to confirm it, or the bot does.


You can do this by setting up a interval that confirms the confirmations every X seconds, but this method is deprecated I believe, you should now be using;

           community.acceptConfirmationForObject(data.identity_secret, offer.id, function(err){

              console.log('Succesfully confirmed the offer.');

Replace with your bots identity secret and the offerid of the sent out offer.

Edit: might of misread it.

  • Dr. McKay and venfiw like this

#5237 How do I choose the right server host?

Posted by Dr. McKay on 07 March 2018 - 06:23 PM

DigitalOcean is fine. I'd recommend them more now that they've dropped their prices than I would in the past. If you're going with a VPS then you need to read up on security so you don't get pwned.


You probably want at least 2 GB of RAM. 1 GB might work but keep in mind that it also needs to support the entire OS too.


On a reputable host your files are safe. You don't need to encrypt them unless you're really paranoid, and if you do go that route you can't store the key on the server or it'll defeat the purpose.

  • Go Fast and derogs like this

#5119 Asking for steam guard code after few hours working

Posted by Vanilla on 09 February 2018 - 08:00 AM

Correct me if I'm wrong, but isn't it should supposed to be like this?

community.on('sessionExpired', function(err) {
	if (err) {
		console.log('sessionExpired: '+err);

Also, another way to bypass Steam Guard Code is using loginKey

  • Igaresha and McMuffinDK like this

#497 Error sending trade offer (15)

Posted by danek on 05 April 2016 - 01:53 PM


What mean this error:


Error: There was an error sending your trade offer.  Please try again later. (15)


  • loyare74 and clisteri like this

#4199 Send/receive messages to/from non-friends

Posted by Dr. McKay on 23 August 2017 - 04:24 PM

You should be able to send messages to non-friends if you're in a group chat with them, but that's about it I think.

  • Kim and TheGoldenPotato like this

#3982 How do I get comments in a steam profile?

Posted by Vanish on 28 July 2017 - 05:26 AM

How to get a comment that is posted in a steam profile

  • LeighHyday and ReighHyday like this

#2838 Send items problem

Posted by Soska on 03 March 2017 - 10:56 AM

Hello. There was such problem: when the bot sends two DIFFERENT trades at the same time, for example where there are two or three of the same case. One trade is accepted, the other gets the status "Items unavailable for trade"
Items are sent by Market name (the classid and instanceid is always the same. they do not have sense). assetid in the offer and the inventory are different.
The task such: to send items that are not currently in other trades of the account.

  • ArlaSokindy and Penneyliz like this

#1537 Minimal code to stay logged in forever...

Posted by Dr. McKay on 06 August 2016 - 11:03 PM

That all looks fine to me. sessionExpired is only emitted when a request you make fails because you aren't logged in. It doesn't check automatically, it only checks whenever the library makes a request somewhere.


Starting a new confirmation checker without stopping the old one is just fine. It'll stop an old one if you call it while one is running.


I recommend updating to v3.23.1 if you're going to use webchat.

  • yellowish and klonaway like this

#143 TradeOfferManager v2

Posted by Dr. McKay on 03 March 2016 - 02:10 PM

Here's an idea. Three options for createOffer():

  1. manager.createOffer(steamID); // create an offer without a token. you can set it later
  2. manager.createOffer(steamID, token); // create an offer with a token
  3. manager.createOffer(tradeURL); // automatically extract the SteamID and token from the trade URL

  • Mole and PEPZ like this

#1088 not confirm trade after running a while

Posted by speicher on 17 June 2016 - 03:38 PM

ok, that should work based on your wiki.
community.on('sessionExpired', function(err) {
	if (err) {
		console.log('sessionExpired: '+err);
	if (client.steamID) {
	} else {

  • T1MOXA and Royalgamer06 like this

#5689 Explanation of EFriendRelationship enums

Posted by Dr. McKay on 30 May 2018 - 11:09 AM

I'm not 100% certain, but I think:

  • Blocked = You blocked them
  • IgnoredFriend = They're a friend, and you blocked them
  • SuggestedFriend = Dunno, maybe unused
  • Max = Not a real value, just the maximum that enum goes up to

  • nikikiker likes this

#3789 Why loadUserInventory doesn't return the market_hash_name?

Posted by Dr. McKay on 02 July 2017 - 11:32 PM

loadUserInventory is deprecated. Use getUserInventoryContents instead.

  • Nacho likes this

#3233 Debug

Posted by Dr. McKay on 01 May 2017 - 06:39 PM

Do this instead:

community.setCookies(["steamLogin=1||invalid", "steamLoginSecure=1||invalid"]);

  • DevDuck likes this

#1914 Auto smelt and craft metal?

Posted by TextDynasty on 16 October 2016 - 01:49 AM

You can use node-tf2 to get and craft your inventory.

Sorry i don't know how to use it.

i have tried this

client.on('craft', function (craft) {

Any examples? Thanks. 


And also how to make a list of my backpack?

  • 72juju likes this

#1592 v3.13.0

Posted by System on 14 August 2016 - 08:38 PM

  • Fixed potential crash if Steam sends bad gift data
  • Added methods to change account email and password

View on GitHub
  • MrRobot likes this

#4374 How to check, if someone commented on a announcement?

Posted by TomYoki on 26 September 2017 - 06:37 AM

I don't believe this is currently possible (in node-steamcommunity; it will never be possible in node-steam-user).

While we're on this topic, are you planning on adding these features to node-steamcommunity, and something like a feature to get Group comments, as a lot of people are wanting to make a bot that can remove people spamming "Come to this awesomesite.csgo/getScammed.php for free moneeeeeys!!1" .

  • SayWhat likes this