FAQ

Is Eclair Wallet a "real" Lightning Node ?

Yes it is. Eclair Wallet is a real, self-contained lightning node that runs on your phone. It does not require you to run another Lightning Node node at home or in the cloud.

Which version of Android is supported by Eclair Wallet ?

Eclair Wallet requires Android 5.0 or higher

Can I receive lightning payments with Eclair Wallet ?

Not yet. Being able to receive payments means that you have to monitor the blockchain and react when your peer publishes an old state, which is both costly to implement and requires to be online typically once a day everyday, which may not be possible for mobile wallets that could be offline for days.

I read that I can lose money if my node goes offline. Is it true ?

No, see above: Eclair Wallet can only send payments so it does not make sense for your peers to try and cheat you, they would publish states that give them less money than the current state.

Is there an iOS version of Eclair Wallet ?

No, and we do not have short term plans to release one.

Can I restore my seed on another bitcoin wallet ?

Yes. Your seed (the 12 words that eclair will display when you start it for the first time) is a standard BIP30 seed with a BIP49 derivation path, which can be restored on any BIP49 compliant wallet. With Electrum for example, you would choose "I already have a seed", tick the BIP39 checkbox,and then select BIP49.

I don't see my eclair-wallet node on LN explorers ?

Mobile nodes (and more generally terminal nodes that don't relay payments) are not public and will not be found by LN explorers. Other nodes won't have them in their routing table and won't display information about them.

I already have installed the testnet version of Eclair Wallet. Can I also install the mainnet version ?

Yes, they are 2 different, independent applications, with different identifiers and data directories.

I think I have enough money, but eclair says "None of your Lightning channels has enough balance to send this payment" ?

You cannot send all (or almost all) of your balance, you have to keep some of it:

• you need to maintain a reserve (which you can see in the "Channel Details" view when you select a channel)
• and you must also keep enough funds to pay for the on-chain bitcoin fees (the state of your channel has to be publishable, this is what enables you to close your channels whenever you want even if the peer you are connected to is gone).

Why does my >$5 payment to LN shops fails, while my <$1 payments to e.g. yalls work?

That's probably a liquidity issue: everybody is trying to pay the same few merchants leading to channels quickly getting unbalanced.

The current state of the network (mostly <$10 channels) doesn't really allow routing payments worth more than $5. The best solution currently would be to open a channel directly with the merchant you are trying to pay. As the network grows that kind of problem will disappear.

Why do some of my payments fail with an expiry too big error ?

Each payment has an expiry, after which you get your money back if your peer has not replied. When you send a payment it will remain pending until it has expired, been completed, or failed. Eclair wallet will not send payment that have an expiry of more than a week (which means that payments could remain pending for more than a week !). Each node set its own delay that is added to the payment expiry, typically 144 blocks (one day), but some nodes set a very high delay (more than a week) which makes it nearly impossible to route payment through them unless the route is very short.

I'm trying to open channel to another node, but right now I'm locked at WAIT_FOR_FUNDING_LOCKED

Depending on what node you are connecting to, they may require more confirmations that eclair, in that case you just need to wait.

My channel was closed uncooperatively. Are my funds locked ? Do I need to do something to get them back ?

There are 2 ways 2 close a channel:

• mutual, or cooperative: both nodes are online and negociate a final onchain fee and publish a tx that immediately sends their funds back to their bitcoin wallet
• unilateral or uncooperative: one node decides to close the channel (typically because one node decided to close the channel while the other node was offline, or because they disagree on current fees...). The node that closed the channel must wait until the closing tx has been confirmed a number of times (typically 144 confirmations, equivalent to 1 day, but it can be much more and this delay is set by the peer you connect to) before it can spend it and return the funds to the node's bitcoin wallet. This is automated and you don't have anything to do, eclair will monitor the blockchain and return the funds to your wallet as soon as possible. Of course you need to start the app for this to work.

Once the transaction that returns funds to your bitcoin wallet has been confirmed the channel will disappear from the channels tab.

My channel has been is CLOSING state for more than a day. I though that I would get my money back after 144 blocks ?

If you are using eclair-wallet 0.3.0 on Android then please checkout the answer below.

If you are using the desktop/server version of eclair, or a newer version of the mobile app, then it is most liekely because the peer you opened a channel with set a higher delay than the commonly used 144 blocks delay: the delay after which you get your funds back into your onchain bitcoin wallet (eclair is both a bitcoin wallet and a LN wallet) depends upon how the peer you connect to is configured. Most nodes use a fixed delay of 144 blocks (one day), but it can be changed by the node operator, and some implementations will compute a dynamic delay based upon the channel capacity (delays will be longer for larger channels) that could be as long as one week.

Is it safe to delete the app, reinstall it and restore the seed? Will I recover all my funds?

As long as you have your seed recovery words, you will recover all your on-chain funds.

For the funds locked in your lightning channels:

• If you've enabled the lightning channels backup feature prior to deleting/reinstalling the application, you will be able to restore your channels later. When reinstalling the wallet with the same seed, you'll just need to allow the application to access your Google Drive account.

• If you have not enabled the lightning channels backup feature, make sure that you've closed all your channels first before deleting the application. If one of the peers you are connected to is unreachable, you must "force-close" the channels you've opened with them, then wait until the closing transactions has been spent and the funds are returned to your wallet (see the answer to the question above).

I am using Eclair Wallet 0.3.0, which was pulled from Google Play Store. What am I supposed to do ?

You should close all your open channels, recover your funds, install the new Eclair Wallet 0.3.1 application, transfer all your funds to Eclair Wallet 0.3.1 and then uninstall Eclair Wallet 0.3.0. Here is a step-by-step tutorial

Step 1: close all your channels

If you don't have any open channels, you can go directly to Step 3.

If you do have open channels, you need to close them. If all the nodes you're connected to are online and you channels are in NORMAL state, you can close them cooperatively, and your funds will be returned to your wallet. It should take a few seconds. Once the closing transaction has been confirmed 3 times, your channels will be closed and will disappear from the Lightning Channels tab. You will then be in the "I don't have any open channels" case described above.

If some of the nodes you are connected to are offline, you will need to close them uncooperatively, and then wait (typically 144 blocks, or about 1 day) before your funds can be returned to your bitcoin wallet.

Step 2: recover your funds

If all your channels we closed cooperatively, you have nothing to do. They are not displayed in the Lightning Channels tab anymore. If some of your channels have been closed uncooperatively, and the 144 blocks delay has passed, you should have recovered your funds and your channels should have been closed. They are not displayed in the Lightning Channels tab anymore. If some of your channels are still stuck in CLOSING state, even after the 144 blocks delay has passed the please follow this tutorial, and contact us on gitter if you need help.

Once all your channels have been closed, go to step 3

Step 3: transfer all your funds to Eclair Wallet 0.3.+

Install Eclair Wallet 0.3.1+ from Google Play. Eclair 0.3.0 and 0.3.1+ are different, isolated applications with different data directories and can safely be installed side-by-side. Then you have 2 options:

• restore your existing seed in Eclair 0.3.1. Once it is done, both versions of Eclair will show the same bitcoin balance, and you can safely uninstall Eclair 0.3.0
• create a new seed in Eclair 0.3.1 and transfer all your funds: once you've created a new seed in Eclair 0.3.1, swipe to the Your Bitcoin Address tab on the left, and copy your bitcoin address. Go to Eclair 0.3.0, to the Transaction History tab, click on the Send icon in the bottom right corner and select Paste a payment request. You should now see your Eclair 0.3.1 address in the To field. Tick the Empty Wallet checkbox, which will fill the amount field with all your available funds (minus the onchain fee) and click pay. This will publish a transaction that transfers all your funds from your Eclair 0.3.0 wallet to your Eclair 0.3.1 wallet. Once this transaction is confirmed you can safely uninstall Eclair 0.3.0