Frequently Asked Questions

What is the Lightning Network?
My Blixt it doesn't sync, why this and what can I do?
What fees are used? Is there a cost to use LN channels?
How is it possible to have a node on a mobile device?
Can I route payments with Blixt Wallet?
With which nodes can I open lightning channels?
How do I connect Blixt Wallet to my own full node?
Can I remotely control an Umbrel from Blixt Wallet?
I lost my mobile phone (dead, stolen) or simply want to migrate to a new phone, what is the procedure?
I restored my old node using SCB file, but funds are not back to my onchain wallet

What is the Lightning Network?

Before you start using Blixt Wallet, it's good idea to get familiarized with terms, procedures, features etc.

It's good idea to start reading and get some basic knowledge about LN and how to use it, otherwise it will be difficult for you as new user, to understand what are you doing with Blixt Wallet as a node LN wallet.

Here are some resources to start learning:

A. General Information and documentation about Lightning Network

B. Video tutorials about Lightning Network and Bitcoin nodes

My Blixt it doesn't sync, why this and what can I do?

First of all let's explain some aspects WHY is not syncing, so the user can understand the situation:

Blixt app need to be online (connected to internet) in order to connect to Neutrino node and sync the block headers and filters. If your device for some reason is not connected to a stable internet connection, Blixt will stale the sync until is restarted.
If you use Tor network, also this connection is quite unstable sometimes and not because your device but because of poor or congested Tor relays in your area.
Keep in mind that Blixt is also using quite some good amount of space data on your device, up to 1.5GB, so be aware to have enough free space, otherwise the app will stop the sync.
Sometimes the sync was not done properly and the app didn't scanned well all your BTC addresses used.
If you switched to sync with your own home node, maybe your node was not prepared for this or connection with your node was intrerrupted.

So what you can do?

Restart Blixt app (even try force close, for closing bad connections).
Remove Tor connection (if is possible and you want it) and restart Blixt.
Switch back to default sync server node.blixtwallet.com or just leave it blank.
Go to settings and check the option "rescan wallet", then restart the app. Once it started, look into lnd logs and wait patiently to finish.
Check if you have enough space on your device, move some apps, fotos, videos to your mSD card and leave more space on local disk. Blixt needs up to 1.5GB for its data (block headers, LN graph, channels.db etc).
Restart app then go to settings, to the last section named "LND Help Center" and run some diagnostics. Get in contact with Blixt support in Telegram group for further instructions or sharing lnd logs.

What fees are used? Is there a cost to use LN channels?

1. Blixt Wallet itself do not charge any fees for usage of the app.

2. Use of Lightning Network (LN) is not free. This is a myth. Even if the cost of using LN is really small, there is a cost and some users will look at that cost too.

3. Opening and closing channels on LN have a cost. and sometimes it's not cheap. It depends also of the miner fees in the moment of opening a LN channel. Sometimes can be high, sometimes can be really cheap. Users should first learn about how these things works. Here is a simple guide about mempool fees. Here is another guide about LN fees.

USE CASE SCENARIO:

You are a new Blixt Wallet user and you just installed the app, you have no funds deposited into the wallet.

Let's consider you choose to use Dunder LSP service (see down below how it works and what is LSP), just to deposit 100k sats into your Blixt LN wallet.

In the moment LSP service received your 100k deposit, it will use it those 100k sats to open a 400k channel (amount can vary, see here more details ) towards your wallet. So you will have 100k sats as outbound liquidity and a 300k sats inbound liquidity. But that opening has a cost: onchain fees for the tx and also a commit fee (reserve kept for closing the channel). See more details about commit fees here: Link 1 - Link 2 - Link 3.

With which nodes can I open lightning channels?

TO REMEMBER:

Blixt Wallet is using private channels, not routing channels.
You can open channels with whatever other node peer, but choose wisely.
Blixt Wallet being a private node wallet and mostly for quick payments, you will need to find the best routes: cheap, fast, well connected peers and reliable.
You can connect to your own home node, but keep in mind that in that moment your home node will be the liquidity provider for your Blixt Wallet, so be sure you have good routes, good fees and be reliable.
Not every LN node wants / agree private channels. If is a dedicated routing node, usualy they do not want private channels because for them is like "locked" liquidity. So will be better if you can ask first the node operator, if agree with a private channel. You can open directly, but be aware, some of them they can just close the channel because they do not want private channels.

Blixt Wallet itself offer opening channels, using two optional methods, towards Blixt Node Server:

Autopilot, for the moment works only for 1st onchain deposit in Blixt and will open a channel with Blixt Node, for the amount you deposited.
Dunder LSP, Blixt Node Server will provide you an inbound channel until 400k sats, on top of your deposit amount, to start with your first deposit on lightning (if you do not have any other channel). You will need to activate in Settings menu.

Inbound liquidity providers - Blixt also offers a direct link, in wallet, to LNBig and Bitrefill (Thor). Just go to settings, select "Inbound channels services", select the desired one and just follow the instructions provided. Those are used only when you need more "INBOUND" liquidity.

Open channels with any nodes. As we've pointed out, we recommend to choose wisely your peers. Blixt being a quick spending LN wallet, we recommend to find ones with low fees or even zero. Also look in this Amboss Community of Zero Base Fee or many other nodes communities. Remember, your Blixt Wallet needs good positioned peers and low fees, so your payments will be fast and cheap.

A very popular node that offers "zero fees routing" is the ZFR node. We suggest to not open tiny small channels like 20k sats. If you already decided to use a node like this as a peer, at least open a 400-500-600k sats to have enough for your payments and also cover the reserves and costs. Smaller channels are not efficient for both peers. Ther are also many other like that, but keep in mind also the centrality and connectivity with those nodes, not all will offer good routes for your payments.

Also is a very good practice to open channels with those merchants/services you are paying frecquently. Opening a channel with your favorite merchant also can bring you 0 fees, by that direct channel and is like a "line of credit". Anyways you can use that channel to pay also other merchants/services, just be aware of their fees for routing your payment, because if there isn't a direct payment their node will have to route your payment to the next hop until the destination and that imply a cost.

How is it possible to have a node on a mobile device?

Blixt Wallet uses the lightning node implementation lnd and the Bitcoin SPV client Neutrino directly on the phone. Lnd has been configured to work well on mobile devices.

Keep in mind that Blixt Wallet is a Lightning node, with LN channels as any other node. That means that in order to be able to transact on LN, you need to be online, connected, in the moment of transaction. If you do not transact, it's not really necessary to stay online. Blixt, once is open it will take few moments to re-sync the latest blocks through SPV Neutrino and you will be back online. On the other hand, for transacting onchain (not LN) it's not necessary to be online.

Can I route payments with Blixt Wallet?

Blixt, indeed is a LN node, but is not a routing node, is more like a private LN node.

All channels on Blixt are private, that means are not "visible" to the other routing nodes in the network. These are so called "unannounced" channels, used only for private payments.

Your Blixt LN node can receive and send payments, using other nodes as hops, but cannot route others payments through your Blixt node.

That's why Blixt is so special... nobody knows about your payments. Check this short tutorial about LN onion routing

How do I connect Blixt Wallet to my own full node?

Under Settings -> Bitcoin -> Set Bitcoin node you can enter a bitcoin node to connect to

Blixt Wallet does not yet support Tor onion v3, so for the moment, you can use your node only if it's "visible" on clearnet (IP/domain), you must make sure that Bitcoin's P2P port (8333) is forwarded by your router. You can connect to your node via its local LAN IP, but it will then only work if you're connected to your home router.

BIP157 compact filter indexing must be enabled for your node, add this to your bitcoin.conf, if it isn't already set:

blockfilterindex=1
peerblockfilters=1

Can I remotely control an Umbrel from Blixt Wallet?

Blixt Wallet is a fully fledged lightning node in of itself. It's not possible connect and control a remote node.

Rather than controlling your node at your home, enable to Tor and open a channel towards it.

I lost my mobile phone (dead, stolen) or simply want to migrate to a new phone, what is the procedure?

RULE NO.1 - You should always have made a channel backup kept it into a safe place (eg, password manager). If you did that, the procedure is simple and you have two ways (fast and slow) and also two situations to take in consideration (you had funds in onchain or not).

RULE NO.2 - Never use a full backup of a device as a restored backup for BTC/LN wallets. This can end up in losing funds, by broadcasting a wrong state of channels.

NOTE NO.1 - Migration (or funds restore procedure) means creating a new Node ID and move the restored funds to it. This is a better procedure for privacy, safety of funds and easiest way.

NOTE NO.2 - if you still have the original DEVICE still working and online with funds in LN channels, NEVER do the restore procedure on a new device with channels restore options. This action will force close the existing channels and you could get a penalty for that (broadcasting twice the status of channels). You can restore on another device, keeping the original still open, ONLY the onchain wallet/seed, but never put the channels backup.

NOTE NO.3 - After restore process is started and if you do not see in "Lightning Channels" menu that the old channels enters in status "closing" and are not there at all, it is safe to start again the process to restore from backup file. No need to start over from zero with also onchain restore. If your onchain wallet is restored and funds are back, is OK, just continue with LN channels restore.

NOTE NO.4 - If you restore LN channels that were open using Tor network, then BEFORE starting the restore process, go to top right corner and activate Tor. In that way, your Blixt node could "see" the Tor peers and start the closing procedure in normal way.

Scenario A - migrate Blixt to a new device (fast way)

Conditions:

you still have the old device functional
you have a new device ready with Blixt Wallet already installed (but not started yet)
you have funds ONLY into LN channels, the onchain is empty

Procedure:

create a new Blixt wallet instance on the new device (new seed) and save that seed into a safe place (password manager)
wait for Blixt to sync (takes just few minutes), you will see the sync icon on top that disappear
on the new device, go to Blixt settings - activate "Dunder LSP"
on the new device, go to main screen and click on "receive" button and create a new LN invoice to open a Dunder LSP channel
put the amount of total balance available displayed on the old device Blixt (main screen), then press create invoice
with the old device Blixt, scan that LN invoice QR code and pay it. The old wallet will send all available funds to the new one and Dunder will open new channel for you, with that amount
it will take just few minutes until tx is confirmed and channel open on the new device, be patient.
once you see the funds in the new device available, it is recommended to close those old empty channels. If there are some residual satoshis, it will come back to onchain wallet and can be sent later to the new device, using an onchain tx
DONE! Now is safe to wipe Blixt from the old device and funds are safe into the new one

Scenario B - old device is lost, non-functional or non-recoverable (slow way)

Conditions:

you do not have the old device anymore
you have a new device ready with Blixt Wallet already installed (but not started yet)
you have funds into LN channels but also in the onchain wallet

Procedure:

Install Blixt Wallet into a new phone
In the first screen to create or restore wallet, got to top right corner and activate Tor (if you had previously channels open with Tor nodes).
Blixt will restart in Tor mode. Then click on "restore". Fill in your 24 words seed from old wallet, space delimited. Add also the channels.backup file you save it previously and copy it into your new phone memory. Optionally, you can use Google drive, if you have it there.
Click "restore" and wait for the app to do the standard procedure for recovering the funds.
Blixt will close the existing channels and after min 40 blocks funds will be recovered and visible into your onchain wallet. So be patient.
To check the funds, go to main screen, top drawer and enter into onchain wallet. On top right corner you click en see the txs log. After channels were closed and txs confirmed, locktime expired, you will see the funds in tgere.

I restored my old node using SCB file, but funds are not back to my onchain wallet

OK, I had a dead previous node and I used the restore procedure, using the SCB backup channels file into Blixt. I wait for the channels to be closed, but funds are not back into my onchain wallet. What can I do?

Usually there are few possible scenarios for closing channels:

A normal "cooperative close" channels usually takes few blocks (no more than 40), if both peers are online. Then everything goes smooth and fast.
If the other peer of the channel is not online then the closure task enter in force close. This could take at least 144 blocks until funds are released from the lock time. Check on mempool that locktime for the closing tx.
If a normal closure get stuck, for many reasons (mostly because of lost connectivity), then once all the rest of the channels already entered into "waiting to close" state, you could repeat the process, to push again the closure of remaining stuck channels.
Another way to "push" the connection with your lost peers, is to add them manually. Go to amboss.space, search for your peer, copy or scan the QR URI of your peer and go to Blixt Settings --> Lightning Peers --> "+".
To try again a force closing action, go to Lightning Channels screen, select the channel you want to push and swipe on activity view to start again the process.

Once all the channels are initiated into "closing", wait patiently. This process takes time. If you see that on mempool the tx had released the funds, then check into your onchain wallet. If funds are still not there, means that the lnd wallet have to rescan previous addresses and refresh the wallet history. Some UTXOs are linked to "anchor outputs" so are more complicated to get back onchain, depends one to each others.

So when you see that all channels are closed, go to Blixt - Settings - down to the last section that says "rescan wallet". Activate it and restart app (if is not doing automatically).

Only when the lnd is initiated, the rescan take place. Be patient and check the lnd logs (see also in Settings - lnd logs). You will read in there how is scaning a bunch of blocks at once for your restored addresses. Once the process is finished, your should see the funds in onchain.

Try to keep active the Blixt app during this process. If is intrerrupted, you will have to restart again to trigger it.

IMPORTANT NOTES TO CONSIDER (in regards of how LN funds are moved):

When you open a channel of 2M sats with a peer, in the beginning all the sats will be on YOUR side.
You start moving these sats by making payments and/or routing others payments through this channel.
If you do not make your own payments out of your node, means that your balance always will be the same, but some channels will move the sats in and out.
By routing others payments, the dynamic of your channels balances is changing. That means: if you initially had 2M sats and you routed 1M sats, your channel balance will be 1M sats. That means, when you close that channel, you will get back 1M sats and NOT 2M sats that you had initially.
So, before start closing your channels, keep in mind how much you had in total balance in your node, on YOUR side of the channels. That is the amount you will get back. Some channels will be even empty on your side, so don't expect to get sats from those closed channels.