Can lightning channel be recovered from seed phrase?

[FibonacciTrader]

If a user has an open Lightning channel, their Electrum wallet file gets destroyed, and they restore their Electrum wallet from seed phrase, will the Lightning channel be recoverable or will it be lost?

[Shishir99]

If you restore the Electrum wallet from the seed phrase, the Lightning channel should be recoverable. Because the seed phrase is used to bring out all the private keys and addresses associated with your wallet including those which was used for Lightning channels.

If you restore your Electrum wallet, the wallet will regenerate all the necessary private keys and addresses including those which was used for the Lightning channels. Your Lightning channel's state is stored on the blockchain, and the private keys associated with your channels are executed from your seed phrase. Your existing Lightning channel information such as channel balances and channel state should be restored with the rest of your wallet.

[FibonacciTrader]

Your Lightning channel's state is stored on the blockchain, and the private keys associated with your channels are executed from your seed phrase. Your existing Lightning channel information such as channel balances and channel state should be restored with the rest of your wallet.

I appreciate your reply. My basic understanding is that the amount contributed to a Lightning channel is on-chain, but the channel state is stored offline (channel peer-to-peer) to avoid the on-chain transaction fees. Given that, how does Electrum know how to find the offline channel state based on the seed phrase alone?

[Shishir99]

Your Lightning channel's state is stored on the blockchain, and the private keys associated with your channels are executed from your seed phrase. Your existing Lightning channel information such as channel balances and channel state should be restored with the rest of your wallet.

I appreciate your reply. My basic understanding is that the amount contributed to a Lightning channel is on-chain, but the channel state is stored offline (channel peer-to-peer) to avoid the on-chain transaction fees. Given that, how does Electrum know how to find the offline channel state based on the seed phrase alone?

Seems like I misunderstood. But I  guess there is some confusion in your understanding as well. The lightning network is 2nd layer scaling solution of a blockchain. The channels are funded with on-chain transactions. But when you participate in a lightning network, those transactions, balance, and channel states are off-chain. It's a 2nd layer blockchain. The lightning network transactions are not on the main blockchain.

The lightning channel state is stored locally within your Electrum wallet software. So I guess Electrum doesn't find an offline channel state based on the seed phrase alone. Wait for the expert guys. I have to learn more about these things as well!

[nc50lc]

If a user has an open Lightning channel, their Electrum wallet file gets destroyed, and they restore their Electrum wallet from seed phrase, will the Lightning channel be recoverable or will it be lost?

It depends, it's only possible if you've enabled the setting "Create recoverable channels" when you created the channel.
The setting can be found in the small setting icon on the upper-right hand of Open channel window.
It can't be enabled (grayed-out) if you're using hardware wallet, using BIP39 seed or have a nodeID before the feature implementation (v4.1.0):


In case you want to check if your channels are recoverable from seed, the channel's icon on the left side of channels tab shouldn't have a "crossed-out blue cloud" icon.
Another indication is by checking the "open channel" transaction if it has a "SCRIPT" output containing OP_RETURN encrypted data from your lightning nodeID.

However, just like a manual channel backup, it's only a "static backup" which can't be used to spend or receive,
the only thing you can do to it is to request to force-close the channel to retrieve the funds.

[FibonacciTrader]

The setting can be found in the small setting icon on the upper-right hand of Open channel window.
It can't be enabled (grayed-out) if you're using hardware wallet, using BIP39 seed or have a nodeID before the feature implementation (v4.1.0):

Thank you, @nc50lc ! I was able to export a QR code backup by right-clicking on the channel -> 'Export backup'
https://talkimg.com/images/2023/08/13/GDibd.png
Electrum says it can be recovered by scanning the QR code from the Electrum mobile app.

Note that I use a BIP39 seed and was still able to create the Lightning channel backup.

Cheers.

[nc50lc]

Note that I use a BIP39 seed and was still able to create the Lightning channel backup.

The limitation is only applicable to the automatic channel backup (recoverable channels) that can be recovered via seed phrase.
Manual backup works in BIP39 seed or hardware wallet.

So as originally asked, your channels wont be recovered from seed phrase.

[davey_c]

My hard drive died and took my electrum wallet file with it.
I recovered via my seed phrase but I don't see the lightning channel I had opened.  I assume that means I didn't have a recoverable channel.

Can I request a force close from the other end of the channel?  I'm pretty sure it was the Electrum Trampoline thing, whatever that is.

I found the transaction that opened the channel if that helps.

[mcdouglasx]

My hard drive died and took my electrum wallet file with it.
I recovered via my seed phrase but I don't see the lightning channel I had opened.  I assume that means I didn't have a recoverable channel.

Can I request a force close from the other end of the channel?  I'm pretty sure it was the Electrum Trampoline thing, whatever that is.

I found the transaction that opened the channel if that helps.

You can look up the other party's contact information and ask them to close the channel cooperatively, as this is the cheapest option. If they don't respond, you'll have no choice but to wait for them to close the channel on their own; this could take days or weeks.

[davey_c]

Thank you so much for the reply.

Where would I be able to look up the other party?  I looked for the funding tx id on 1ml.com and amboss.space but couldn't find it.

I have the transaction but Claude tells me that this:
The challenge:
This is a SegWit v0 P2WSH output (witness script hash). The actual channel partner's node ID isn't directly visible in the funding transaction itself - it's obscured by the script hash.

If all I have to do is wait, that's not a problem really.  The channel has already been open for months though, my last activity was probably in September.


Update:
I'm learning.  I found the hard coded options in the github repo and believe it was the electrum trampoline server but it is very likely a private channel.
I tried to contact the developers via github (believing they also run the electrum trampoline server) and was directed back here for non-development questions/issues.

I have the txid that funded the channel.

I'm assuming I could verify that it was me somehow but don't (as of yet) know how.
If someone here could close the channel, that would be awesome.  I could re-reimburse you for your trouble, ain't but ~.002BTC in there.

Maybe send me a personal message or an email if you can help.

[nc50lc]

I'm pretty sure it was the Electrum Trampoline thing, whatever that is.

You'll have to make sure of the name of the remote node.
If it's actually "Electrum Trampoline", you're lucky that it's owned by ThomasV (ecdsa) himself.
Reference: github.com/spesmilo/electrum/issues/8915#issuecomment-1963579459

You can contact him on GitHub (click the linked user's profile).
Also, I don't recommend you to post it as a new issue since it's not actually caused by an issue, you may only do that if you can't contact him.

[davey_c]

Awesome, thanks.

[nc50lc]

Update:
I'm learning.  I found the hard coded options in the github repo and believe it was the electrum trampoline server but it is very likely a private channel.
I tried to contact the developers via github (believing they also run the electrum trampoline server) and was directed back here for non-development questions/issues.
-snip-
I have the txid that funded the channel.

Wait, can you share what you initially told the developers?
Because the issue doesn't look like something that can be solved without the parties involved.
Perhaps there's something more to this (or your messages lacked the key info when you contacted them?)
Of course, if there's something private, you can exclude those.

You may keep the funding transaction private,
Just check the outputs if there's an "OP_Return" output to make sure that it's not an issue where your client can't restore a channel backup.

And you didn't mention if you have already synced Electrum when you restored your seed.
Because the trick in the recoverable static channel backup feature is in the funding transaction and not just the seed phrase.

[davey_c]

I did't actually get to the point where I left them a message.

In the repo, when creating a new issue, a pop-up directs you back to bitcointalk.org for non-development related issues.

Thanks for thinking more on this.

"Just check the outputs if there's an "OP_Return" output to make sure that it's not an issue where your client can't restore a channel backup."

There is an OP_Return output to the transaction.


"And you didn't mention if you have already synced Electrum when you restored your seed.
Because the trick in the recoverable static channel backup feature is in the funding transaction and not just the seed phrase."

synced Electrum? Is that a separate operation beyond just restoring from a seed phrase?  I don't see it in the GUI.

I don't know if the recoverable static channel feature is enabled by default (or if it was back in September).  I may not have selected that option.



FYI I'm talking to ThomasV over on github about this as well.  I think that might have been a mistake, the scammers found me over there.

Update:
Following ThomasV's instructions, I simply re-restored via my seed phrase and everything works.  Restored my channel and requested a force-close.  Maybe a bug, maybe I screwed something up with the original restore, may never know I guess.
Thanks for the help guys, I learned a lot so it wasn't a waste.

[nc50lc]

synced Electrum? Is that a separate operation beyond just restoring from a seed phrase?  I don't see it in the GUI.
-snip-
Update:
Following ThomasV's instructions, I simply re-restored via my seed phrase and everything works.  Restored my channel and requested a force-close.  Maybe a bug, maybe I screwed something up with the original restore, may never know I guess.

Okay, that's why I'd to double-check and asked if there's an "OP_Return" output and if Electrum is synced.
"Sync" as in query your selected server for transactions associated with your wallet, first time install wont immediately sync in seconds without the "block headers" first.
Those are done automatically, but the block headers may take a few minutes to be downloaded in some situations.
Then, your static channel backup wont immediately be restored, its funding transaction should appear in your history first.

TL;DR: My best guess is it wasn't actually synced when you restored it the first time but successful in that last attempt.

[davey_c]

Yeah, what was weird was that I could see all of my on-chain transactions, even the funding tx.

I was actually expecting an issue recovering my lightning channel so when it happened, I didn't question it.  It showed me what I expected so I stopped questioning.  I think there is a life lesson in that.

Yeah, the second time I saw a "syncing" message in the lower left of the gui that I don't remember from the first restore.

I learned a bunch during this so I am grateful.  Thanks for the help.