Dr. McKay

You can pass your own request instance to the constructor, with a proxy configured using request.defaults.

That sounds an awful lot like spam.

Extremely sorry for wasting the time, i figured it out. It was offer.addMyItem, while it should be offer.addTheirItem.

SteamIDs with type 4 are anonymous gameservers, meaning the SteamID is going to change every time the server restarts. If you want a persistent SteamID, you need to register a gameserver account and use the login token you get on your server. Source-based games usually use tokens by adding +sv_setsteamaccount <token> to your server's command line.

It's the time Steam says the offer changed, which would be Tuesday in your example.

It's probably in the descriptions array somewhere.

The market listing ID is the creator property.

item.actions is an array. You need to find the action you want.

I'm pretty sure that means that you need to verify your email before continuing. You can request a verification email with steam-user.

The brackets just mean that it's an optional argument. store.addPhoneNumber('+310***', (err) => {}) is the same as store.addPhoneNumber('+310***', false, (err) => {}).
If you want to bypass a confirmation, you'd do store.addPhoneNumber('+310***', true, (err) => {})
The callback doesn't have any other arguments besides err.

GC sessions are weird and sometimes they go away without wanting to reconnect. That said, some changes have been made somewhat recently, so make sure you're up to date.
If you are, then I suggest detecting when that happens, and using gamesPlayed([]) then waiting a minute or two and launching CS:GO again.

No, you should check when you process the offer. It should be among the first things you check in the offer. 
You can't act on an offer (e.g. decline the offer) after you've accepted it which you are doing in the above code.  

err.eresult is just the number, yes.

There shouldn't be any problems.

getPersonas is a method, not a property.

I deleted useless code
function sendSomeItem() { console.log('function started') const partner = '76561198989375284'; const appid = 730; const contextid = 2; const offer = manager.createOffer(partner); offer.addTheirItem({ 'assetid': 18697938160, 'appid': appid, 'contextid': contextid }); offer.setMessage('Test offer'); offer.send((err, status) => { if (err) { console.log(err); } else { console.log(`Sent offer. Status: ${status}.`); } }); } Now i get function started and error that i must have steam guard for at least 15 days. So i think this is working  Thank you so much for that fast answers <3 

You need to wait for the loggedOn event, and you also need to call getPersonas to actually get user persona data.

Take a look at the examples in the steam-tradeoffer-manager repository. It should be fairly trivial to modify the example to accept all incoming offers into one that declines all incoming offers.

That sounds an awful lot like spam.

Yes, receivedOfferChanged should be your primary way to see if a trade was completed.

This is just how Steam works, sadly. When you confirm an incoming trade offer, the confirmation request doesn't respond until all items have been exchanged. If a trade offer contains many items, it's very possible that the request will time out (30 seconds) before all items have been exchanged. In this situation, the trade will still complete in the background.

You can use steamstore to add phone numbers.

You can use steamstore to add phone numbers.

I don't really know a whole lot about the inner workings of CS:GO, but I'd think that if it's not exposed in the existing profile methods, then it's probably incredibly tricky to retrieve otherwise. I've not seen anything in the protobufs that refer to trust levels.

https://github.com/DoctorMcKay/node-steam-tradeoffer-manager/wiki/TradeOffer#getpartnerinventorycontentsappid-contextid-callback