staticaddr: channel funding with deposits by hieblmi · Pull Request #1040 · lightninglabs/loop

hieblmi · 2025-11-11T20:07:37Z

depends on #1073

This PR introduces a openchannel subcommand to static addresses.

It provides the same experience as lncli openchannel.
Exmples:

Open a channel with all available deposits:

loop static openchannel --fundmax --sat_per_vbyte XXX --private ...

Open a channel with specified local funding amount, coin-selected from available deposits under fee and dust considerations.

loop static openchannel --local_amt XXX --sat_per_vbyte YYY --private ...

Open a channel from two deposits AAA and BBB while taking their combined value(fundmax) as funding amount and considering fees and dust limit.

loop static openchannel --utxo AAA --utxo BBB --fundmax --sat_per_vbyte YYY --private ...

Open a channel from two deposits AAA and BBB while taking a specified amount(local_amt) as funding amount and considering fees and dust limit.

loop static openchannel --utxo AAA --utxo BBB --local_amt --sat_per_vbyte YYY --private ...

TODOs:

Integration tests

gemini-code-assist · 2025-11-11T20:08:35Z

Summary of Changes

Hello @hieblmi, 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 significantly extends the functionality of static addresses by enabling them to be used as a source for funding Lightning channels. It introduces a new openchannel command that integrates a robust PSBT-based funding flow with lnd, offering flexible options for selecting deposits. This enhancement allows users to seamlessly convert their static address funds into channel liquidity, thereby increasing the utility and versatility of static addresses within the Lightning ecosystem.

Highlights

New openchannel subcommand: Introduced a new openchannel subcommand under loop static which allows users to fund Lightning channels directly from their static address deposits.
Flexible Channel Funding Options: The new command supports various funding options, including fundmax to use all available deposits, local_amt for a specified amount, and explicit UTXO selection, mirroring the experience of lncli openchannel.
PSBT-based Funding Flow: The channel funding process leverages a Partially Signed Bitcoin Transaction (PSBT) flow, enabling secure and collaborative transaction construction with lnd.
New Deposit States: Added new deposit states, opening_channel and channel_published, to track the lifecycle of deposits used for channel funding.
Code Refactoring and Reusability: Common utility functions related to PSBTs, Musig2 sessions, and outpoint handling have been refactored into a new staticutil package, improving code organization and reusability across static address features.

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gemini-code-assist

Code Review

This pull request introduces a new openchannel subcommand for static addresses, allowing users to fund channels from their deposits. The implementation is comprehensive, covering the command-line interface, RPC definitions, daemon logic, and documentation.

My review focuses on the new cmd/loop/openchannel.go file, where I've identified a few issues related to context handling, input validation, and error wrapping. These are important for ensuring the robustness and maintainability of the new command.

The refactoring to move utility functions into a staticutil package is a great improvement for code organization and reuse. The protocol changes to use PSBT for withdrawals are also a solid enhancement.

Overall, this is a well-structured PR that adds significant functionality. Addressing the feedback will further improve its quality.

cmd/loop/openchannel.go

hieblmi · 2025-12-12T10:04:44Z

@gemini-code-assist review

hieblmi · 2026-02-26T16:29:43Z

@starius addressed recent comments in commit e0934b6

starius

LGTM! 💎
Thanks! Great work!

staticaddr/openchannel/manager.go

Remove unreachable error check after filterNewDeposits which does not return an error. The err variable was already handled from the ListUnspent call above and could never be non-nil at this point.

Block-based deposit fetching from the internal lnd wallet was susceptible to wallet syncing issues. Replace it with interval-based polling. Reconciliation errors are now logged instead of being fatal, improving resilience during transient failures.

Protect the shimPending variable with a sync.Mutex since it is accessed from multiple goroutines: the main loop goroutine and the server error handling goroutine. Without synchronization this is a data race.

Return an error instead of just logging when chainhash.NewHash fails in the ChanPending handler. The hash variable would be nil and crash on the subsequent String() call.

…ublished Both OpeningChannel and ChannelPublished lacked OnExpiry transitions. handleBlockNotification fires OnExpiry on every new block once the deposit is expired, regardless of the current state. Since both states use NoOpAction or FinalizeDepositAction which release the FSM mutex briefly, an OnExpiry SendEvent can sneak in. Add self-transitions so the event is safely absorbed.

Duplicate outpoints in the request lead to fee miscalculation and an invalid PSBT with the same input listed twice. Validate early and return a clear error message.

If the PSBT finalize step succeeds but the stream fails before ChanPending, deposits would remain stuck in OpeningChannel until the next daemon restart. Run the recovery logic immediately so deposits are resolved without requiring a restart. Also, add tests for the following edge cases requested in review: - Reorg: channel tx reorged, UTXOs reappear as unspent, deposits return to Deposited state. - Daemon restart during channel opening: deposits in OpeningChannel recovered based on UTXO status (spent → ChannelPublished, unspent → Deposited). - Mempool eviction: tx evicted, UTXOs unspent, deposits return to Deposited. - Mempool rejection: tx never accepted, same recovery as eviction. - Stream errors: lnd stream fails before PSBT finalize, error returned without errPsbtFinalized so deposits can be safely rolled back. - PSBT finalize then stream abort: finalize succeeds but stream dies before ChanPending, error wrapped with errPsbtFinalized so caller triggers recovery instead of blind rollback. - Duplicate outpoints: already covered by TestOpenChannelDuplicateOutpoints.

gemini-code-assist bot reviewed Nov 11, 2025

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hieblmi force-pushed the static-open-channel branch 4 times, most recently from f9b49dc to 9d37fca Compare November 12, 2025 10:24

hieblmi self-assigned this Nov 17, 2025

hieblmi added the static-loop-in label Nov 17, 2025

hieblmi force-pushed the static-open-channel branch 9 times, most recently from 94f45cc to 375cf47 Compare November 19, 2025 07:55

hieblmi force-pushed the static-open-channel branch 9 times, most recently from 2b9378a to 5b6631d Compare December 9, 2025 15:05

hieblmi requested review from bhandras, sputn1ck and starius December 10, 2025 18:53

hieblmi force-pushed the static-open-channel branch 3 times, most recently from b5a9b2e to fae04ea Compare February 26, 2026 16:24

starius approved these changes Feb 26, 2026

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hieblmi force-pushed the static-open-channel branch from fae04ea to d5d124b Compare February 26, 2026 19:26

starius reviewed Feb 26, 2026

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hieblmi force-pushed the static-open-channel branch 2 times, most recently from 788a7b2 to 092740d Compare February 26, 2026 19:48

hieblmi added 14 commits February 26, 2026 20:57

go.mod: go mod tidy

9800ee3

deposit: remove dead code in reconcileDeposits

f1c138a

Remove unreachable error check after filterNewDeposits which does not return an error. The err variable was already handled from the ListUnspent call above and could never be non-nil at this point.

staticaddr: channel open states for deposit and fsm

d12663e

staticaddr: open channel manager

dfc75f2

staticaddr: close quit channel only once

63097ee

loopd: instantiate static address open channel manager

b74dab8

notifications: fix test race

d2d8e71

openchannel: fix shimPending data race

eaf7883

Protect the shimPending variable with a sync.Mutex since it is accessed from multiple goroutines: the main loop goroutine and the server error handling goroutine. Without synchronization this is a data race.

openchannel: return error on hash creation failure

52d884c

Return an error instead of just logging when chainhash.NewHash fails in the ChanPending handler. The hash variable would be nil and crash on the subsequent String() call.

openchannel: reject duplicate outpoints in open channel request

e710ea5

Duplicate outpoints in the request lead to fee miscalculation and an invalid PSBT with the same input listed twice. Validate early and return a clear error message.

openchannel: optimize open channel request creation and err handling

6cb54ed

hieblmi force-pushed the static-open-channel branch from 092740d to a9e763f Compare February 26, 2026 19:57

cmd: open channel command

79120cc

hieblmi force-pushed the static-open-channel branch from a9e763f to f192914 Compare February 26, 2026 20:16

docs: update loop.md

c700650

hieblmi force-pushed the static-open-channel branch from f192914 to c700650 Compare February 26, 2026 20:22

hieblmi merged commit 802cf87 into lightninglabs:master Feb 26, 2026
9 checks passed

hieblmi deleted the static-open-channel branch February 26, 2026 20:39

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staticaddr: channel funding with deposits#1040

staticaddr: channel funding with deposits#1040
hieblmi merged 16 commits intolightninglabs:masterfrom
hieblmi:static-open-channel

hieblmi commented Nov 11, 2025 •

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hieblmi commented Dec 12, 2025 •

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hieblmi commented Nov 11, 2025 •

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