Fee Warning on Sweeps

[editwentyone]

Figma

Warning: Sweeps will use a more conservative estimate for the mining fee, which might end up being 80% more expensive than anticipated.

[theborakompanioni]

Ping @kristapsk..
Is

Warning: Sweeps will use a more conservative estimate for the mining fee, which might end up being 80% more expensive than anticipated.

a somewhat valid statement?

(Primary main objective is to make the user aware of it - not for them to know the technical details).

[kristapsk]

Ping @kristapsk.. Is

Warning: Sweeps will use a more conservative estimate for the mining fee, which might end up being 80% more expensive than anticipated.

a somewhat valid statement?

(Primary main objective is to make the user aware of it - not for them to know the technical details).

No, fee estimation is the same. But output and fee amount is calculated for initial number of counterparties, if some of them drop during the process, actual feerate will be higher.

[theborakompanioni]

Ping @kristapsk.. Is

Warning: Sweeps will use a more conservative estimate for the mining fee, which might end up being 80% more expensive than anticipated.

a somewhat valid statement?
(Primary main objective is to make the user aware of it - not for them to know the technical details).

No, fee estimation is the same. But output and fee amount is calculated for initial number of counterparties, if some of them drop during the process, actual feerate will be higher.

Thanks @kristapsk 🙏
Hmm.. okay, I am still unsure on how to properly re-phrase the warning message to reflect that. I am specifically looking at https://github.com/JoinMarket-Org/joinmarket-clientserver/blob/35e6f286fb9be0dc90c2c5c7648d380c103a3870/src/jmclient/taker.py#L357-L368:

est_ins = len(self.input_utxos)+3*self.n_counterparties
jlog.debug("Estimated ins: "+str(est_ins))
est_outs = 2*self.n_counterparties + 1
jlog.debug("Estimated outs: "+str(est_outs))
self.total_txfee = estimate_tx_fee(
    est_ins, est_outs, txtype=self.wallet_service.get_txtype(),
    outtype=self.wallet_service.get_outtype(self.coinjoin_address()))

Where est_ins assumes 3 inputs by counterparties, and from my understanding, the inability to adjust a change output, increases the fee - not the dropping during the communication process. And with max_sweep_fee_change being 80% by default, I am currently not sure how to come up with a correct and concise message.

On a side note: It would be nice to have access to estimate_tx_fee via RPC!

[theborakompanioni]

Ping @kristapsk.. Is

Warning: Sweeps will use a more conservative estimate for the mining fee, which might end up being 80% more expensive than anticipated.

a somewhat valid statement?
(Primary main objective is to make the user aware of it - not for them to know the technical details).

No, fee estimation is the same. But output and fee amount is calculated for initial number of counterparties, if some of them drop during the process, actual feerate will be higher.

Thanks @kristapsk 🙏 Hmm.. okay, I am still unsure on how to properly re-phrase the warning message to reflect that. I am specifically looking at https://github.com/JoinMarket-Org/joinmarket-clientserver/blob/35e6f286fb9be0dc90c2c5c7648d380c103a3870/src/jmclient/taker.py#L357-L368:

est_ins = len(self.input_utxos)+3*self.n_counterparties
jlog.debug("Estimated ins: "+str(est_ins))
est_outs = 2*self.n_counterparties + 1
jlog.debug("Estimated outs: "+str(est_outs))
self.total_txfee = estimate_tx_fee(
    est_ins, est_outs, txtype=self.wallet_service.get_txtype(),
    outtype=self.wallet_service.get_outtype(self.coinjoin_address()))

Where est_ins assumes 3 inputs by counterparties, and from my understanding, the inability to adjust a change output, increases the fee - not the dropping during the communication process. And with max_sweep_fee_change being 80% by default, I am currently not sure how to come up with a correct and concise message.

On a side note: It would be nice to have access to estimate_tx_fee via RPC!

@kristapsk Would you be able to clarify your thoughts on this? Would be nice to release soon and have this included. People have raised their unhappiness with the mismatch between their fee expectation and the actual fees paid on sweeps quite often lately and it should at least contain a proper explanation on why that is. At least until a proper fee estimate (maybe by accessing estimate_tx_fee via RPC) can be provided. Is it really only higher if makers drop during the process? Any suggestion would be highly appreciated.