I'm a bot trying to help you to complete your badges. I can accept both same set and cross set offers.

For same set:

I accept 1:1 trades for same set cards.
Just send an offer and it will be automatically accepted
Nothing extra is asked, 100% free.
Any cards, it doesn't matter if foil or not, marketable or not.

For cross-set:

I trade foil cards and normal ones aswell.
It's value based. Each card has a value in 'credits'.
The credits value for each card is calculated using its market price. 1 USD = 100 credits aprox.
To prevent abuse, cards value can have a maximum of 15 credits. If a card is more expensive than that, it will be taken as it has 15 credits value.
If you can afford the credits cost of an offer, then it will be automatically accepted. Otherwise it will be declined.
The offer cost is calculated using MY_CARDS_VALUE - YOUR_CARDS_VALUE + 2 credits
That 2 credits fee is added to all cross-set tradeoffers. It's just to try to avoid loosing cards and help mantain the bot. I think 2 credits is fair, it's the same than Steam market fee to sell each card, but here you can include any amount of cards in the offer, as the fee is per offer, not per cards amount.
You can however send any of those as donation (and other kind of items aswell). That would be really appreciated, but of course it's not needed and you won't get any advantages doing it.
If you are giving more item value in credits than the one you are asking for, your extra credits will be added to you balance. This means you can use that credit in next offers.
Example: if you have 3 credits in you balance, and you send an offer wich costs you 2 credits, then the bot will accept it, it will just discount 2 credits from your balance.

Cards value is updated every 1 hour. So if you think a card value is wrong, you can try to just wait some time.

You don't need to be friend with the bot to be able to send offers. But you probably want to know more if your offer was declined, for example.
Then you have 2 options, if you add the bot to your friends list, the bot will send you some details on why an offer was declined, or data about your balance.
For the other option, I have made a website https://jaks.cf/skajbot/
There you can see detailed resume of your last offer if you log-in onto the site. Anyway there's no need to be logged on site, as the bot will send you a permalink with details of the offer via chat if he considers that it's needed (only if you are in bot's friends list).

To prevent abuse, if you send items without asking nothing in return the offer will be considered as a donation, and therefore no credits added to your balance. This project isn't meant to profit, just to help others to complete their sets. If donations are received they will be used to expand the bot's inventory.

You can always use my STM Quickmatch link to help matching your dupes. Feel free to add me just to compare from badges page.