How To Send eCash Tokens To Nostr Users

Nostr has taken the bitcoin ecosystem by storm, with many a pleb signing up to use the protocol and testing out available clients. One widespread use for Nostr is sending users satoshis via the Lightning Network; users would post invoices or assign a static LN-URL to accounts in the early days to facilitate payments.

As the use case became more popular, clients began integrating better methods of sending satoshis to users through improved UX. With the latest merge of NIP-57, Zaps (sending sats and associating the data with accounts and posts) are now part of the Nostr protocol.

For Nostr users to accept Lightning payments, they would need either a custodial or non-custodial Lightning wallet set up that supports Lightning Addresses. This a setup that not every Nostr user has taken advantage of, with many accounts not having a LUD-06 identifier.

If you’re on Nostr and would like to tip a user, but they do not have a Lightning Address in their bio or set up in their profile to accept tips or, as Nostr users call it, Zaps, then fear not, there is still a way to pay these users and allowing them to claim the funds with their Nostr key and eCash.

eCash Tokens on Nostr

eCash is a free and open-source Chaumian ecash system built for Bitcoin as an additional scaling solution. eCash mints can be seen as another layer to the broader bitcoin ecosystem, as the protocol can live on top of the Lightning Network. Users can fund an eCash mint with bitcoin, and once eCash tokens are minted, they can be sent to any other user who has signed up for that specific mint.

 eCash mints can be run by an individual or federation of members similar to the Liquid Network, depending on the implementation.

• FediMint operates as a federated mint with multiple members acting as custodians.
• Cashu is *not* a federated system like Fedimint is. A single entity controls a Cashu mint.

So while there is trust involved, there is a lower risk of funds being lost as several parties need to collude to seal funds in a FediMint. At the same time, a Cashu mint is easier to operate and experiment with being a single custodian. 

Set up an eCash wallet.

If you’re the practical type and aren’t satisfied with a simple explanation and prefer to find out by doing it yourself, then let’s dive in. Get your hands dirty with this third layer of bitcoin and set up your very own eCash wallet.

• Visit nutstash.app
• Select the wallet for quick access or run a python wallet locally.
• Once launched, head over to the settings.
• Toggle the nostr option.
• The wallet will prompt you to sign in using your Nostr key; you can use any Nostr key management tool to sign in.
• Toggle the use external key option.

Now you’re done with the setup of your eCash wallet, and it’s now time to fund it by minting your first eCash tokens.

Fund your wallet

If you’re starting with a 0 eCash balance with any of the mints you have attached to your wallet, you will have to fund it with satoshis via the Lightning Network. To mint eCash tokens using Nutstash, you will need to follow these steps.

• Select the mint option from the home screen.
• Select the mint you wish to fund.
• Click mint and set the number of eCash tokens you would like to mint. Remember, 1 token = 1 Satoshi.
• Select request mint.
• Pay the invoice.
• Click mint.
• Your wallet should now be funded with the Satoshis you paid into the mint.

Now that you have eCash tokens, you can pay anyone with an eCash wallet by creating a claim invoice and sharing it with the user in question. Alternatively, you can send the funds to them using their Nostr account.

Send funds to a Nostr user.

Now that your wallet is funded and ready to fire off, you need to find the destination you want to send it to, which is easier said than done. Depending on the client you’re using, you could see a user’s Hex Pub Key on their profile or in the URL slug when visiting their profile.

But in bitcoin, we don’t trust; we verify, so you’re best off using a tool like Nostr Band and pasting either the user’s Hex Pub Key or Npub into the search and checking the results. Compare it with what you see in the client or copy the Hex key directly from the result given to you by Nostr Band.

Now that you have a HEX key and are confident it’s for the correct user account, it’s time to fire off some eCash payments.

• Click send.
• Select the mint you’ve funded.
• Select the number of tokens you wish to send.
• Ensure that the mint allows you to send that amount.
• Click send
• You will be presented with a token invoice you could post on social media for others to claim, but instead, you want to send them to someone. It might be a good idea to copy the invoice and save it somewhere in case you want to sweep the funds due to a technical issue.
• Now take the hex key and paste it into the field for “send it to a nostr Pub Key”
• Then click send over Nostr, and you’re done.

Recommendations after sending funds

You’ve completed your end of the deal; it’s now up to the Nostr user you paid to access their wallet and claim their tokens. If you do plan on sending eCash tokens to Nostr users, it’s important to note that:

• The user will need to set up their own Nutstash wallet and tie it to their Nostr account by signing into the wallet with any Nostr Key Management Tool.
• The user will also need to add the mint you’re using, so provide them with the mint URL you’re using.
• The user will receive a Nostr DM with the claim invoice, but they might not know what to do with this random string of text. There is no way for the user to know you’ve sent them funds, so it might be wise to DM them and explain what is potting or leave a comment on one of their posts unless you’re keen on playing hide the satoshi with them.
• If the user does not redeem the funds or you made a mistake sending it to the wrong hex key, you can use the invoice you copied earlier to sweep those funds back into your eCash wallet.
• You can monitor the status of your transaction from the wallet by selecting the token option from the wallet’s main menu. If the eCash tokens have not been claimed, they will remain in a pending state.
• If sent, you should see the confirmation under the history section of the wallet.
• If the user doesn’t want to deal with an eCash wallet, they can skip the wallet setup process and use the redeem invoice in their Nostr DM to sweep the funds directly to a Lightning wallet using redeem.cashu.me

Once the user claims their tokens, they can either keep it in their eCash wallet to send to someone else later on or sweep the funds by paying a Lightning invoice. The eCash tokens representing those satoshis will be destroyed, and the funds will be unlocked to a Lightning wallet of the user’s choice.

Warning: These wallets are by no means thoroughly tested and are in BETA! The operators of the software or default mints hold no responsibility for people losing access to funds. Use at your own risk!

Ecash is a bearer asset, meaning losing access to this wallet will mean you will lose the funds. These wallet stores ecash tokens locally in your browser, so do not use a private window or clear your cache. This mean if you lose the link, your nostr key, or delete your data without backing up, you will lose your tokens.

The tokens in the wallett are stored in the browser’s local storage and are unencrypted. If someone has access to that browser or device, they can steal the tokens.

If you are planning to hold funds in an eCash wallet, please ensure that you use the “Backup button” to download a copy of your tokens or sweep your eCash wallet to a Lightning wallet instead.

You have been warned, so please don’t send us any emails or DMs about how you lost your sats messing around with eCash.

At the moment, sending eCash tokens to Nostr users works with HEX keys only, but support for nPub keys is in the works.

A future for eCash and Nostr

eCash makes different trade-offs to Lightning; while it does introduce a custodian of sorts, it does offer unique UX options that have much lower friction and a learning curve for users. It’s far easier to onboard users to an eCash wallet than giving them the song and dance that is channelling the Lightning Network. eCash is a great option for novice users to get involved with bitcoin, especially as Nostr onboards users outside the bitcoin community.

As this technology matures, it could be added directly to clients or Lightning Wallets for easier interaction with your Nostr keys and make for a native tipping option.

Users of specific communities could set up mints to facilitate mico-payments with one another privately or set up their own private markets to trade goods and services with a low friction and low fee solution.

In addition, eCash tokens can be a payment method for Nostr-related services such as paid relays or NIP-05 verification.

Are you on Nostr?

If you are a Nostr user and want to hang out and chat with us or follow our content on your preferred Nostr front end, feel free to add us using our PubKey below, and if you’d like to try sending us some eCash tokens, you can use the same PubKey in conjunction with the instructions outlined above.

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The Bitcoin Manual’s Nostr Pubkey

Please give us your notes.

If you have used Nostr, which client do you prefer and why? Are there any clients that you think deserve mention? Have you used eCash tokens?

Let us know in the comments down below.