Chapter 2.2 - Handling Trade Offers

Chapter 2.2 - Handling Trade Offers

To start off this chapter, let's duplicate the code we made in the previous chapter to a new file. Call it project2.js. The code we wrote in Chapter 1 will be the code we use from now on to create all of our bots. It will be the backbone for future bots we create.

Let's begin adding some code to the top of our project, copied from project1.js.

const SteamUser = require('steam-user');
const SteamTotp = require('steam-totp');
const SteamCommunity = require('steamcommunity');
const TradeOfferManager = require('steam-tradeoffer-manager');

const client = new SteamUser();
const community = new SteamCommunity();
const manager = new TradeOfferManager({
	steam: client,
	community: community,
	language: 'en'
});

[...]

Sweet. We required two new modules, and created new instances for both of them. In addition, we passed some extra parameters to the TradeOfferManager module's constructor. We told it to use our client variable when it would like to access Steam, and our community when it would like to access the Steam Community. If we did not specify these options, a new instance of these modules would be created inside of our TradeOfferModule instance, but we provide our own so we can have more customizability in the future. We also tell TradeOfferManager to use the English language so that we can get the English names of items in the trade offers.

Let's add some more code while we're at it.

client.on('webSession', (sessionid, cookies) => {
  manager.setCookies(cookies);

  community.setCookies(cookies);
  community.startConfirmationChecker(10000, 'your_identity_secret');
});

Here, we added a new event listener to the client instance. We're listening for the webSession event, which is emitted when we get a session id and cookies back from the Steam servers. Then, we pass those cookies to our manager and community, which will allow them to be logged into Steam as well. We also tell our community instance to start checking to see if we have any pending confirmations every 10 second, and accept them if we do. This requires you to enter your identity secret, which we address in Chapter 1.4.

Sweet, so now we have our manager, client and community all logged into Steam. Now let's try doing something with all this. We'll start by accepting all incoming trade offers if they come from an account we trust. Let's give it go.

manager.on('newOffer', offer => {
  if (offer.partner.getSteamID64() === 'your_trusted_account_id') {
    offer.accept((err, status) => {
      if (err) {
        console.log(err);
      } else {
        console.log(`Accepted offer. Status: ${status}.`);
      }
    });
  }
});

Alright, this was quite a bit of code, but let's go through it step-by-step.

First of all, we added an event listener to our manager. This event listener listens for the newOffer event, which is emitted when we receive a new offer. Next, we check if the 64 bit Steam ID of the sender is the same as the one we trust. For example, I would replace your_trusted_account_id with 76561198092490523. That long number you see is my Steam account's 64 bit SteamID. It's easy to find this number – it's in your Steam account's permalink. Mine can be seen at steamcommunity.com/profiles/76561198092490523.

If the two Steam ID's match, then we accept the offer using the offer's .accept() method. We pass a callback to the method, and when the offer is accepted (or gets an error), the callback is called. If all works smoothly, you should see "Accepted offer. Status: pending/accepted/escrow."

To test this out, run the program using node project2.js and use the trusted account to send an offer to the bot. If you don't have a second account, use a friend's Steam ID as the trusted account, and have them send your bot an offer.

Note that your bot needs to have at least a $5 purchase on Steam to be eligible to receive trade offers. Otherwise, the newOffer event will not fire.

Sure enough, when the trade gets sent, something like this should appear in your console:

Then, after giving the program enough time (should be less than ~30 seconds) to confirm the trade with Steam, you should see that it has been accepted on Steam:

Awesome! Assuming it works for you, we can move on.

What if a scammer sends your bot an offer and wants to take your brand new Karambit Fade, or that unusual hat you had been saving up to get? Well luckily, we added that check to make sure that we only accept offers from the trusted account, but we probably don't want a bunch of offers from scammers sitting around, cluttering up our trade offer inbox. We can easily decline these offers by adding a bit more code to what we previously wrote.

manager.on('newOffer', offer => {
  if (offer.partner.getSteamID64() === 'your_trusted_account_id') {
    offer.accept((err, status) => {
      if (err) {
        console.log(err);
      } else {
        console.log(`Accepted offer. Status: ${status}.`);
      }
    });
  } else {
    offer.decline(err => {
      if (err) {
        console.log(err);
      } else {
        console.log('Canceled offer from scammer.');
      }
    });
  }
});

All we did was add an else statement to our Steam ID check, which uses the .decline() method of the offer object to decline the offer. If there is any sort of error, we log that error to the command line. Otherwise, we print out "Canceled offer from scammer."

Great! You have your first simple trade offer handling program. In the next chapter, we'll work on sending offers to users.

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