Who decides the transaction fee in Kaspa?

In Kaspa, the wallet decides how much fee to attach to a transaction — but the network has guardrails. The wallet software you use chooses the fee amount when it builds and signs your transaction. However, nodes (the computers that relay and validate transactions) apply an anti-spam filter that rejects transactions whose fees fall below a minimum threshold, so a fee that is too low will never reach the network. For advanced users running their own node, that minimum fee threshold can be adjusted via the command line. This matters because understanding the fee model helps you know why a transaction might get filtered before it even reaches the network.