is there some possibility to charge a comission fee on each transaction done on an specific smart contract?
For instance, User A swaps 1 ETH by 100k EXAMPLE. At the end of the transaction, User A will receive only 99k EXAMPLE, and the remaining 1k is automatically transferred to User B (like a central account).
Just reinforcing - this doesn't have anything related to gas fee! Is a comission fee on top of the gas fee user needs to pay anyway.