The SteamTrade Matcher bot functionalities are currently limited, expect up to 1 hour wait to have your trade offers accepted.
Guidelines
Important Rules
Only use SteamTrade Matcher for fair trades and not for profit.
Trade offers sent using SteamTrade Matcher should always be 1:1 and from the same set. Sending unfair trade offers or making counter offers adding items for your profit is not something we want here and might get you suspended from using this service if reported.

Make it easy for those who receive your trade offers.
Avoid sending multiple trade offers at the same time to one user, try to group all the items you want to trade in a single offer instead. Also, it is recommended to add a comment stating that the requested items are duplicates. And saying you're coming from SteamTrade Matcher always helps of course ;)

Do not always trust the scanner.
Scanned inventories are cached to increase performance, so the results you'll get might not always be up to date and other trades might have happened in between. Always try to check the other user still have multiple units of the item you want from them before sending your trade offer.

Do not always trust other users either.
You should always check trade offers you receive. The other user might have mistakenly added the wrong item, or he might even be trying to scam you. Always make sure you indeed have duplicates of the requested items, and that the trade offer is fair. Make sure to report any scammer if they are a SteamTrade Matcher user.

Keep it spam free.
Please do not include spam, referral links or anything undesirable in your trade offer comments while using SteamTrade Matcher.

Enjoy using SteamTrade Matcher!
Happy trading!
F.A.Q.
What is SteamTrade Matcher?
SteamTrade Matcher is a tool designed to help you complete your sets of Steam Trading Cards, and fulfil your emoticons and profile backgrounds collections by matching your duplicate items with those of other SteamTrade Matcher users. It allows you to quickly know which ones they might be willing to trade and what you could give them in exchange while making a fair trade for both parties.

How does it work?
When using the scanner, SteamTrade Matcher will compare your inventory with those of all the other publicly listed users. All the duplicate items in your inventory will be listed in order to determine trade possibilities within the same game/app. For instance, if you own a duplicate Steam Trading Card for a game, and you're missing a card from the same game that some SteamTrade Matcher users have two or more copies of, the scanner will check if any of them is missing your duplicate card to complete their badge. If they do, the trade possibility will be displayed to you. The only thing left to do is then to start a trade offer with them!

Is it safe? Is it a scam?
Of course! Logging in to SteamTrade Matcher is done through the Steam website. This means you don't have to enter your Steam credentials here. The only data SteamTrade Matcher can get is your public Steam information, like your Steam ID, name, status and inventory content.

How do I use it?
Just log in using the "Sign in through Steam" button. This will allow you to authenticate you as the owner of your Steam account. Make sure your inventory privacy setting is set to "Public" so your inventory can be scanned. You're ready to go!

How can I report a bug I found on SteamTrade Matcher?
Feel free to report any problem you might encounter on the bug report forum in the SteamTrade Matcher Steam group.

What can I do to help?
Feel free to donate if you want to help me maintain and pay for SteamTrade Matcher's hosting. Also, make sure to share the website with your friends and join the SteamTrade Matcher Steam group to get the latest news, and to discuss and share ideas.

I own a 1:1 card trade bot. How can I make it appear as such in the public listing?
1:1 trade bots have a special status on SteamTrade Matcher which will make them able to be matched with different criteria than normal users. For instance, bots don't necessarily seek to trade duplicates in trade offers. This special status can be requested from your settings page and will require validation. Bots need to obey some special rules to be able to get this status, and only a limited amount of bots are accepted on the website at the same time.