Chapter 2.3 - Sending Trade Offers

Chapter 2.3 - Sending Trade Offers

Now that we know how to handle incoming trade offers, sending them shouldn't be too much more difficult. Let's add some more code to our project2.js so that it sends a specific user a random item from our inventory.

How about we start off by fetching a random item. Think about how we might go about this. First, we're going to load our inventory (which is loaded as an array of items), then we'll choose a random number from 0 to the number of items we have in our inventory. We'll use that number to fetch a specific item from our inventory.

Let's start coding. First we'll create a new function.

function sendRandomItem() {
  manager.loadInventory(440, 2, true, (err, inventory) => {
    if (err) {
      console.log(err);
    } else {
      const offer = manager.createOffer('partner_steam_id');
      const item = inventory[Math.floor(Math.random() * inventory.length - 1)];

      offer.addMyItem(item);
      offer.setMessage(`Lucky you! You get a ${item.name}!`);
      offer.send((err, status) => {
        if (err) {
          console.log(err);
        } else {
          console.log(`Sent offer. Status: ${status}.`);
        }
      });
    }
  });
}

Whoa, okay, that was quite a bit of code. Let's go through what it does. When this function is executed, it first loads our TF2 inventory (appid 440 – if you want to send a random CS:GO item change this to 730), which has a contextid of 2. The next parameter we pass is whether we should only load tradable items – we say true. We then create a new offer using manager's .createOffer() method. This method takes a Steam ID, so make sure you set it to another account which you want to send an item to. Then we choose a random item in our inventory and set it to the item variable. We add this item to the offer using its .addMyItem() method, and we set the message using .setMessage(). Then, after all that, we send the trade using .send().

We just need to add a little bit more code for our bot to work. We'll need to edit the webSession event listener.

client.on('webSession', (sessionid, cookies) => {
	[...]

	sendRandomItem();
});

This is pretty simple, it just executes the function we created above. Now, let's run the bot using node project2.js. Hopefully, you should see "Sent offer. Status: sent/pending." message appear in the command line.

You should also get a trade offer containing the random item within about 10 to 30 seconds.

Let's add one more little feature to the bot – we should ask for one of their items in exchange for our's. At this point in time, we won't bother checking if it's a good deal or not, but we'll get into that later in a future chapter.

Let's change up our code from the sendRandomItem() function a bit. This code will look pretty ugly, but we'll worry about making it more pretty in the future – this is a proof-of-concept.

function sendRandomItem() {
  const partner = 'partner_steam_id';
  const appid = 440;
  const contextid = 2;

  const offer = manager.createOffer(partner);

  manager.loadInventory(appid, contextid, true, (err, myInv) => {
    if (err) {
      console.log(err);
    } else {
      const myItem = myInv[Math.floor(Math.random() * myInv.length - 1)];
      offer.addMyItem(myItem);

      manager.loadUserInventory(
        partner,
        appid,
        contextid,
        true,
        (err, theirInv) => {
          if (err) {
            console.log(err);
          } else {
            const theirItem =
              theirInv[Math.floor(Math.random() * theirInv.length - 1)];
            offer.addTheirItem(theirItem);

            offer.setMessage(
              `Will you trade your ${theirItem.name} for my ${myItem.name}?`
            );
            offer.send((err, status) => {
              if (err) {
                console.log(err);
              } else {
                console.log(`Sent offer. Status: ${status}.`);
              }
            });
          }
        }
      );
    }
  });
}

Alright so we changed this code up quite a bit. In short, we are now loading their inventory as well and adding their item to the trade using the .addTheirItem() method.

Try running this code now and see what happens. It should create a trade looking something like this:

Nice. Obviously this will result in some pretty crazy trade offers, but again, we'll get into price checking in a future chapter.

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