A great companion for your public node - Blixt BTC ⚡️ LN Node & Wallet

Posted about 3 years ago by DarthCoin

I would like you to present a new interesting and also powerful mobile BTC / LN node and wallet - Blixt. Name is coming from Swedish and means "lightning".

How I discovered this tiny little gem?
I have an Umbrel LND node and wanted to have a backup plan to restore quick my node in case of SHTF. So I found this mobile wallet that support to restore from SCB backups the entire node funds. Then I start testing it more and found out that

THIS IS FULL NODE IN YOUR OWN POCKET

Don't forget that, this is very important!

If you want to read and learn more about nodes, here you have another guide.

At the end of this article you will find some quick guide demos, how to use it and connect to other nodes.

This is an amazing app for Android and iOS that can run a BTC LND node, in your own pocket. Yes, unbelievable, right?! In your own mobile you can have ready a BTC LN node in less than 10 min, with rich features for power users but also trying to give a seamless experience for new Bitcoin users or not so tech-savvy ones.

Blixt Wallet is built as an MIT-licensed open-source project and it has its niche of users that want to start with BTC LN but do not have the means of running a full node machine or just want a mobile node.

Here are some links about this new wallet node app:

Official site - also with nice interactive demo
GitHub repository - check development stages and download sources
Telegram support group - where you can ask quick questions directly to developer
Android Blixt app download
iOS Testflight App download

Main features available:

Neutrino node
Blixt connects by default to Blixt Server to sync the Neutrino blocks and indexes (SPV mode), but user can also connect to its own node. It is surprisingly sync the whole SPV node in less than 5 min (in my case on Android 11) and I was ready to use the full node wallet (onchain and LN).

Full non-custodial LND node
User can manage its own channels with an easy interface and enough information shown to have a good experience. In the top left drawer menu you can go to Lightning channels and start opening with other nodes, as you wish. Don't forget to activate Tor from settings first. Is much better for privacy and also being a mobile node, if you change a lot your internet connection / clearnet IP, your peers can get confused. With Tor node URI you will have always same private ID whatever location / IP you have.

Backup / restore LND node
Powerful feature, easy to manage, useful to restore other dead LND nodes, just with the 24 words seed + channels.backup file.
Here is a guide about how to restore dead Umbrel nodes into Blixt in case of SHTF.
User also have the option to save Blixt channels backup into Google drive and / or local storage in own mobile (later move that file into a safe location, out of your phone).
The restore procedure is quite simple: insert the 24 words seed, add the backup file (previously copied into mobile memory) and click restore. It will take some time to sync and scan all the blocks for your txs in the past. Channels will be automatically closed and funds returned to your onchain wallet (see the drawer menu on the left top - onchain).

Notes:

- if you previously had channels open with your old node behind Tor, you should first activate Tor option (and restart app) from menu settings. In this way, the closing procedure will not fail and/or use force close option.

- remember to make a backup of your LN channels after you open and / or close channels. Takes just few seconds to be safe. Later you can move the backup file to a safe location out of your mobile.

- to test your seed in a restore scenario, before adding some funds, just use the same 24 words seed (aezeed) into Bluewallet. If the BTC address generated is the same in Blixt, you are good to go. No need to use Bluewallet after that, you can just delete the restored test wallet.

Tor integrated
Once you activate it, app will restart behind Tor network. From that moment you can see in menu settings, your nodeID with an onion address, so other nodes can open channels towards your little mobile Blixt node. Or let's say you have your own machine node at home and want to have small channels with your mobile Blixt node. A perfect combination.

Dunder LSP - Liquidity Service Provider
Amazing simple feature that offer to the new user the possibility to start accepting BTC over Lightning Network straight away, with no need to deposit funds onchain and after that opening LN channels.
For new users this is great, because is supposed that they can start from zero, directly into LN. Just create a LN invoice from main screen "receive", put the amount, description etc and pay from another wallet. Blixt will open a max 500k sats channel per received transaction. You can open multiple ones, when is needed.
An interesting and useful case is this: let's say your first receive amount is 200k. Blixt will open a channel of 500k sats and with already 200k (minus opening fees) on your side, but you still have 300k available "space" to receive more. So next payment of 100k will come directly to this channel, with no more fees and you still have 200k space to receive more.
But if you choose for the next receiving payment let's say 300k, it will create another new channel of 500k and pushing to your side those 300k.
Blixt can modify the size of opening a new channel if there are too many inquiries.

Open channels automatically
In settings, the user can activate this option and have an automated service that open channels to best nodes and routes with available balance in onchain Blixt wallet. This is a good feature for new users that do not know too much about with which node and how to open a LN channel. is like an autopilot for LN.

Remember: this option is used only once, when you create your new Blixt wallet and is activated. So if the new user, see the onchain QR code on the main screen and deposit to this address his first sats, Blixt will open automatically a channel with those sats, with the Blixt public node.

Inbound channel services
Dedicated feature for merchants that need more INBOUND liquidity, easy to use, just select one of the liquidity providers in the list, pay the amount you want channel and provide your Tor onion node ID where the channel will be open towards your Blixt node.

Contact list
Useful feature if you want to have a stable list of destinations where you are going to pay most of the time. This list can be LNURL, Lightning Address or future static payment information/invoices. Fro the time being this list can’t be backed up, but it is plans to have an option to export it.

Send to Lightning Address
Direct option to send to any LN address if is not in your contacts list. Soon maybe will have option for own @blixtwallet.com LN address.

LNURL support
Can scan/pay/login with LNURL, but for the moment it doesn't work if the LNURL is behind Tor.

Keysend
Very powerful feature that few other mobile wallets can have it. You can send / push funds directly through a channel or pointed to another node, adding a message if is necessary. This feature is very useful for posting messages on Amboss.space Billboard (here is a guide about that Amboss billboard).

Sign messages
Very useful tool to sign messages with your node key, login authentication messages and so on. Very few mobile wallets have this feature, almost none.

Multi-Path payments
Good and useful feature for LN payments, to split a LN invoice payment into multiple parts, from multiple channels. Good for balancing liquidity and also for increased privacy.

Lightning browser
Series of LN 3rd party services, organize together into a nice simple browser accessible and at hand for the user. It's a nice way also to promote businesses that accept BTC over LN. This is a feature to be more developed in the future. For the time being it doesn't work behind Tor so browsing these apps will be in clearnet.

Logs explorer
Powerful tool to check up the LND logs and node state in general. Options to save the logs file. Very good to have at hand these logs in case you need support from developer to identify some issues.

Security
You can set in menu settings, for more security of you node wallet, the option to login with pincode and/ or fingerprint.

Onchain wallet
This part is a bit hidden, in the top left drawer menu. Being not so often used by a power LN user, is not firstly visible on the main screen. But that's OK, you can have it like a separate wallet where you can manage addresses and see txs log. Maybe in the future will include also some kind of coin control feature.

Mini guides use case scenarios with Blixt

A. Opening channels towards your mini node Blixt

For Android users:

1. Go to Blixt settings - activate Tor - restart app (force close if is not restarting automatically)

2. Wait for Blixt to open in Tor mode and sync the latest blocks

3. Go to settings - see “Show Tor onion service”, copy it, is your Blixt node URI

4a. Go to your Umbrel app RTL or TH (I prefer this) - add peer and paste your Blixt onion URI

4b. Go to your Umbrel node dashboard or RTL/TH - open channel, and select known peer from list looking for your Blixt nodeID

5. Put the amount of sats for the channel, click open

6. Wait 3 confirmations to have a new channel with your "mini node" Blixt

Optional: if you open a channel towards your Umbrel node, you can even push funds onto your Umbrel node side, by using Blixt keysend option.

For iOS users:

1. Go to Blixt settings - activate Tor - restart app

2. Wait for Blixt to open in Tor mode and sync the latest blocks

3. Go to your Umbrel node, copy the Tor URI or show the QR code

4. Go to Blixt - Settings - Show Lightning Peers - Add peer and scan or paste the URI of you Umbrel node. It will be added as known peer.

5. Go back in Umbrel Thunderhub app, Open channel menu and as peer select from drop down box of existing peers.

6. Put all the rest of details for opening the channel, click Open

7. Wait for 3 confirmations to have open that channel and done, now you have more inbound liquidity in your Blixt side. Optional you can push with keysend part of the funds on Blixt side.

B. Opening LN channel towards a Umbrel node

This time we will open a channel FROM Blixt, to our own Umbrel node (for example), to test Tor connection and usage. Later, once is open we can balance that channel by pushing half or the amount desired to the Umbrel side. This also can be used as an “escape valve” when your main Umbrel node need more liquidity.

1. Go to your Umbrel node and copy the onion URI of your node, or just pull up the QR code for onion URI.

2. Go to Blixt - Settings - Lightning peers - add new peer

3. Scan QR code from your Umbrel node or paste the onion URI and your Umbrel node will be added like peer.

4. Go back to main screen - top left drawer - Lightning channels

5. Click on open new channel “+” sign and paste the onion URI or scan the QR code of your Umbrel node. Add amount of sats for the channel, fee and click open.

6. Done, channel will take 3 confirmations to be open and… Happy Lightning with your own Umbrel node.

C. Receive funds straight to LN wallet
This is an amazing simple experience to receive funds directly in your fresh open Blixt node wallet, no need to deposit funds and manually open channels with specific nodes.

1. Once you create the wallet and save the seed, go to settings and activate Dunder LSP

2. Go back to main screen - click on receive, put the amount, I tested with 200k sats

3. It will create a LN invoice to be paid from another LN wallet

4. Dunder LSP service will create a channel of max 500k sats and push those funds you sent (200k in our case) on your channel side. So you will have a nice channel ready to send and receive.

5. If you want to receive more, next payments will be received in the same channel, until the max 500k is fulfilled. If there’s no more “space” to receive in the same channel, Dunder will create a new channel, in the same procedure.

6. Save a backup of your new opened channels. Always after opening new or closing ones. It’s very easy and fast and can save you from much trouble.

This is a perfect use case for new small merchants that want to start accepting BTC.

IMPORTANT TIP

before start using these Tor channels and Blixt app was long time not open/synced, try waiting for the sync icon on top to finish and check if all channels are online active. Then just go and create your transactions.
If the channels are still not active, then go and add again the peer public key/ onion URI into peers, in Blixt options - show peers. You could try also refreshing that list, if the Tor gossip will find your peer, the channels will be back to life. if not, just add it again and will push the gossip to communicate.
But remember: do not just blindly jump into making a tx immediately after you open Blixt app. takes only moments to check if your channels are active, before getting error route or insufficient funds.
Being a LN node, it is strongly NOT recommended to use same seed on two different devices. It can be done this procedure ONLY in case you are in a recovery process, when the onchain wallet generated from seed it will start syncing previous txs and balances and without the LN channels.backup, will not start full restore procedure. So yes, you will see same onchain wallet on both devices but NOT the LN one. And DO NOT try to restore on both same LN channels. You will lose funds!

Conclusion

So, these are some of the main features (for a mobile wallet, a lot right ?) from many others and will come more.

The experience with this node wallet app was very pleasant and easy to use, highly well responsive app, no major issues, just little things that need to be added (but not so important). Is still a young app and needs a lot of testing in real cases. Don't be shy to try it and inform the developer about any issues that can be fixed or improvements.

Let’s also not forget: is an open source project and amazingly maintained by one-man developer, that is doing all the job. So please help him with testing and feedback and most important, have patience and report with details if you find some issues or app needs more improvements.

Blixt have a nice way to add more features, requested by users - post yours here: https://features.etleneum.com/blixt

I hope you will enjoy using it. I personally like it and is very useful for me (see here a use case where this wallet is a great tool).