Hi everyone, I am trying to learn more about op_ctv (or its true name, op_securethebag). One thing I keep hearing is that estimating fees are potentially an issue when spending CTV transactions. jamesob mentioned fees in his simple_ctv_valut *Because coins may remain vaulted for long periods of time, the unvault process is sensitive to changes in the fee market. Because use of OP_CTV requires precommiting to a tree of all possible specific outputs and the number of inputs, we cannot use RBF to dynamically adjust feerate of unvaulting transactions.* and rustyrussell on nostr also mentioned fees being a problem *Optimised sponsors for solving the "but how do I add fees" problem in a way that doesn't drive miner centralisation.* With v3 transactions available in bitcoin 28.0 there are a bunch of new techniques that have been enabled that we can use to hopefully solve these issues As long as you have an output for 240 sats paying to a P2A address, such as tb1pfees9rn5nz on signet, you or anyone else will be able to bump the fees using CPFP on the anchor output. I have some examples of these transactions here on signet CTV spend transaction with zero fees: https://mempool.space/signet/tx/32f4f4e6165e7f8df9b9a762e11a6ca7f16087713e0e3e42352021e6bf3800e3 P2A CPFP transaction: https://mempool.space/signet/tx/9a3582f03b0ac39cff8ed024cf8f38e4fc4a1ee2ff216badf041bf4572c0d03b Code used is here: https://github.com/stutxo/simple_ctv Is there anything I am missing here? What are the downsides of this method? Is this how most ctv scripts spends would work? Thanks! stu -- You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/5565b149-48b7-4823-9363-89cfd70ecf09n%40googlegroups.com.