Ordinals and inscriptions are technologies for creating non-fungibility on bitcoin. There are key things to consider when securing inscribed UTXOs.
If you haven’t set up Casa yet, please see Setting up your Casa vault for ordinals and inscriptions before proceeding.
Ordinals are a way to put a numerical order on sats on the bitcoin blockchain.
Inscriptions are similar to NFT (non-fungible token) art on ethereum, but on the bitcoin blockchain. Inscribing is a way to add art directly onto the bitcoin blockchain and tie it to an ordinal satoshi (the smallest portion of a bitcoin).
In this support article, we’ll cover how you can use Casa to safely store and preserve your inscriptions when sending.
While storing and sending ordinals / inscriptions is possible within the Casa app, the Casa app’s current version was not designed for this purpose. Using the Casa app to store and send your ordinals / inscriptions comes with risk, and you should evaluate and test the Casa app thoroughly before deciding to use the app to secure your inscriptions.
UTXOs
A UTXO in bitcoin refers to an "unspent transaction output" on the blockchain. A UTXO can contain one or multiple sats, the smallest unit of bitcoin.
Ordinals are sats that connected to specific UTXOs that a user owns. Casa's unique UTXO management system makes storing ordinals and inscriptions possible.
How do I receive an ordinal / inscription to my Casa vault?
To receive an ordinal to your Casa vault, you can simply send a transaction to a deposit address of your Casa vault. We recommend using a "subaccount" in your vault to store your inscriptions separately. This will allow you to keep the UTXOs containing your ordinal sat(s) separated in different pools. It's also important that you only receive a single transaction (the one containing your ordinal) to a single address - do not receive more than one bitcoin transaction to an address containing an ordinal. This helps Casa maintain a one-in-one-out structure for your UTXO's, and ensures your ordinal is not lost when you send it. After you receive a transaction and it shows up in the Casa app, Casa will automatically display a new receive address the next time you want to receive - please double check that your transaction is confirmed in the Casa app before receiving more bitcoin to that subaccount.
If you haven't configured your subaccount yet, please see Subaccounts in the Casa app for details.
We highly recommend using the "Memo" feature within the Casa app to label the incoming transaction containing the ordinal sat with the name of the inscription. This will be very important later, and allows you to keep track of your inscriptions and make it easier to find the relevant address when sending your ordinal in the future.
See our article Transaction memos for more info on how to do this.
While you can manage the specific UTXOs in your Casa vault, the Casa app does not currently allow users to view the inscribed images associated with your ordinal. You can, however, use a website like ordinals.com to view inscription images.
How do I send an ordinal / inscription?
We advise that you move / send your ordinal infrequently. The reason for this is because running out of sats to cover the network transaction fee is a real possibility, which leaves your ordinal "stuck" until you are able to add additional funds to that UTXO. Adding funds to a UTXO is not possible today in Casa, or any other bitcoin wallet aside from the command line ord wallet. This is why ensuring the UTXO has sufficient funds to meet future fees when sending is of paramount importance.
To send an inscription from anywhere, Casa included, you need to send the entire UTXO, and only that UTXO, in your transaction. This means the UTXO needs to be large enough to cover fees without sending the entire amount, since part of it contains an ordinal sat with an inscription on it. Casa makes it possible to do this.
To start, tap on the vault you're sending from, then tap "Send." Before sending, select "Send from" at the top of your screen to select the specific address containing your ordinal.
On the next screen, select the address containing your ordinal.
Once you select your UTXO, select "Send max" from the send screen to autofill the full amount of the UTXO which contains your ordinal sat.
We recommend choosing your transaction speed and selecting "Slow" to reduce the fee size, or customize your sats/b transaction fee to a low fee prior to sending. Remember: there must be enough BTC in the UTXO you're spending from in order for the transaction to be sent.
Do note that when sending a transaction with a low fee, the transaction will take longer to confirm. If you are sending to yourself, and are not concerned about the confirmation time, a low fee is the better option. If you are sending to an exchange or other service to sell the item, choosing a slightly higher fee may be better, but the fee must always be lower than the amount of BTC in your UTXO.
To illustrate the importance of lowering your fees, imagine that the UTXO is a deck of cards, with each sat in the UTXO as a single card. When inscriptions are created, they are tied to the top card in the deck. When transactions are sent, miner fees are deducted from the bottom card in the deck. After being passed around enough and giving cards to miners (paying fees), the UTXO deck runs out of cards from the bottom, and the top card in the deck - the inscription - may accidentally be given to a miner!
Once you’ve selected your fee, you can sign and send the transaction. See Sending funds from a vault in Casa app for more information on applying all necessary signatures to complete your transaction.
Once you have applied the appropriate signatures to the transaction and have broadcast it to the network, you and the recipient can use a block explorer like mempool.space to track the transaction and block confirmations.