add sats_per_kweight option when crafting a transaction (continue) #10067
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This commit has to include all these subsystems because the rpc value sat_per_byte is replaced with the sat_per_kweight option and otherwise the commit would not be compilable by itself. lnrpc: For OpenChannelRequest, BatchOpenChannelRequest, SendCoinsRequest SendManyRequest, CloseChannelRequest and EstimateFeeResponse the sat_per_kweight field is added or replaced for the deprecated sat_per_byte field where applicable. This allows for more fine granular control of transaction fees. lnd: Fee calculation for sendcoins, sendmany, openchannel, closechannel has now the option sat_per_kweight. The option sat_per_byte is replaced by sat_per_kweight. In addition a safety check is added to prevent very high fees. For the estimatefee cmd the fee in sat_per_kweight is added to the response. lncli,itest,lntest: remove usage of sat_per_byte option.
Add the sat_per_kweight for the rpc calls FundPsbt, BumpFee and Pendingsweeps. Where applicable the sat_per_byte option is replaced by the sat_per_kweight option.
Adopt the option sat_per_kweight for batch channel openings.
Add new itests for openchannel,sendcoins,sendmany, fund psbt and bumpfee rpc calls. In addition the RBF logic is now tested in the itests (bumpfee) resolving an outstanding TODO.
The deprecated option sat_per_byte is replaced by the new sat_per_kweight option where applicable otherwise it is added. Add the sat_per_kweight option for the lnrpc cmds sendcoins, sendmany, openchannel, batchopenchannel, closechannel. Also return the sat_per_kweight for estimatefee in the response. Add sat_per_kweight option for walletrpc cmds "wallet psbt fund" and "wallet bumpfee".
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Summary of Changes
Hello @MPins, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request enhances fee rate control within the system by introducing a sats_per_kweight option for various on-chain and channel-related transactions. This change provides more granular control over transaction fees, which is particularly beneficial for advanced users managing Lightning channels. The update involves modifications to the command-line interface, RPC definitions, internal fee calculation logic, and comprehensive integration tests to ensure correctness and prevent conflicting fee specifications.
Highlights
- New Fee Rate Option: Introduced a new
--sat_per_kweightoption across variouslnclicommands andwalletrpccalls, allowing users to specify transaction fees in satoshis per kiloweight (sat/kweight). This provides finer control over fee rates, especially useful for advanced channel management. - API and Protocol Updates: Updated
lnrpc/lightning.protoandlnrpc/walletrpc/walletkit.prototo include the newsat_per_kweightfield, replacing the deprecatedsat_per_bytefield. Corresponding Swagger and generated Go files have been updated. - Fee Calculation Logic Enhancement: Modified the internal
CalculateFeeRateutility to properly handle the newsat_per_kweightinput, ensuring that only one fee rate type (sat_per_vbyteorsat_per_kweight) can be specified at a time. A security measure was also added to cap the effective fee rate at a default maximum. - Expanded Command Support: The
--sat_per_kweightoption is now available forlncli openchannel,batchopenchannel,sendcoins,sendmany, andclosechannelcommands, as well aswalletrpc FundPsbtandBumpFeecalls. - Integration Test Coverage: Added new integration tests to verify the correct application of
sat_per_kweightfor channel opening, sending coins, and sending to multiple addresses, including tests for mutual exclusivity withsat_per_vbyte.
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MPins
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Code Review
This pull request introduces a sats_per_kweight option for more granular fee control in various transaction-related commands. The changes are extensive, touching lncli commands, RPC definitions, and wallet logic. I've added several new integration tests to validate this new functionality.
My review focuses on ensuring consistency in argument validation across different commands, adherence to the style guide, and clarity in documentation and error messages. I've identified a few places where command-line argument validation can be improved and some documentation that could be more precise. Overall, the implementation is solid, and the new feature is a great addition.
| _, err := checkNotBothSet( | ||
| ctx, "sat_per_vbyte", "sat_per_kweight", | ||
| ) | ||
| if err != nil { | ||
| return err | ||
| } |
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Similar to the openchannel command, the batchopenchannel command should also validate that conf_target is not used at the same time as sat_per_vbyte or sat_per_kweight to avoid ambiguity in fee specification.
// Make sure only one fee preference is specified.
feeRate, err := checkNotBothSet(
ctx, "conf_target", "sat_per_vbyte",
)
if err != nil {
return err
}
_, err = checkNotBothSet(
ctx, feeRate, "sat_per_kweight",
)
if err != nil {
return err
}| * [Add sat_per_kweight option for more fine granular control of transaction | ||
| fees](https://github.com/lightningnetwork/lnd/pull/7454). For the commands | ||
| SendCoins, SendMany, OpenChannel, BatchOpenChannel, CloseChannel this option | ||
| is added. Also the walletrpc calls FundPsbt, BumpFee and PendingSweeps | ||
| support the new fee rate option. |
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The wording in this release note could be improved for clarity and conciseness.
| * [Add sat_per_kweight option for more fine granular control of transaction | |
| fees](https://github.com/lightningnetwork/lnd/pull/7454). For the commands | |
| SendCoins, SendMany, OpenChannel, BatchOpenChannel, CloseChannel this option | |
| is added. Also the walletrpc calls FundPsbt, BumpFee and PendingSweeps | |
| support the new fee rate option. | |
| * [Add `sat_per_kweight` option for finer-grained control of transaction | |
| fees](https://github.com/lightningnetwork/lnd/pull/7454). This option | |
| is added for the `SendCoins`, `SendMany`, `OpenChannel`, | |
| `BatchOpenChannel`, and `CloseChannel` commands. The `walletrpc` calls | |
| `FundPsbt`, `BumpFee`, and `PendingSweeps` also support the new fee rate | |
| option. |
| err := bob.RPC.BumpFeeErr(bumpFeeReq) | ||
| require.ErrorContains(ht, err, "either SatPerKweight or SatPerVbyte "+ | ||
| "should be set") |
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The error message being checked here seems incomplete. The actual error message returned when both SatPerKweight and SatPerVbyte are set should include "but not both". Please update the expected error string to match the actual error for a more accurate test.
| err := bob.RPC.BumpFeeErr(bumpFeeReq) | |
| require.ErrorContains(ht, err, "either SatPerKweight or SatPerVbyte "+ | |
| "should be set") | |
| err := bob.RPC.BumpFeeErr(bumpFeeReq) | |
| require.ErrorContains(ht, err, "either SatPerKweight or SatPerVbyte "+ | |
| "should be set, but not both") |
| default: | ||
| return nil, fmt.Errorf("fee definition missing, need to " + | ||
| "specify either target_conf or sat_per_vbyte") |
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The error message in this default case is now outdated with the addition of sat_per_kweight. It should be updated to include the new fee option to provide a more accurate message to the user.
default:
return nil, fmt.Errorf("fee definition missing, need to " +
"specify either target_conf, sat_per_vbyte, or "+
"sat_per_kweight")
This PR continues the work started in #7454 by @ziggie1984
The goal is to allow callers to specify a custom
sats_per_kweightvalue when crafting transactions, enabling finer control over fee rates. This is particularly useful for advanced channel management.Original PR:
#7454
Happy to continue the discussion and iterate on this.