All INCOME payments are totally FREE.
Apirone takes the fixed commission for each OUTGOING payments 0.0002 BTC more than 0.001 BTC. We don't take a fee from amounts less than 100.000 Satoshi. These rules apply to V1 and V2: Saving and Forwarding wallet types.
Forwarding transaction means one incoming transaction and one outgoing transaction.
All technical APIs like Callback or Exchange rate are fully free.