Your account

#One signature

Your Opacus account comes from your Solana wallet. When you open it, your wallet signs one fixed message, which names opacus.tech, and the app turns that signature into your account's keys. Nothing is sent and nothing is paid: a signature is not a transaction.

The keys live only in the app's engine, inside your browser, while the page is open. They are never stored and never leave your device. Each visit starts with one signature.

#The same account everywhere

Solana wallets sign the same message the same way every time. So the same wallet opens the same account on your phone, your laptop or a borrowed computer, with the same balance and history. There is no seed phrase to write down for Opacus: your wallet is the backup.

The first time on a device, the app asks for the signature twice, to make sure your wallet really signs the same way each time. A wallet that does not could never open the same account again, and the app refuses it. The app then remembers which Opacus address this wallet opened on this device, never the signature or a key, and refuses a later signature that would open a different one.

#Your Opacus address

People pay you at your Opacus address: 117 characters that start with opacus1. It is not a Solana wallet address, and a Solana wallet cannot send to it. It is how other Opacus accounts reach you inside the pool. Its last characters are a checksum, so a mistyped or cut address is caught before anything is sent.

Your address is in Receive, with its QR code. If you would rather share something short, claim a short name like @ada.

#Your balance is made of notes

Inside the pool, money is held as notes: each deposit and each payment you receive is a note of yours. Your balance is the sum of your notes, per asset.

Every move spends two notes at most. When a payment needs more than two of your notes, the app first joins them, with free payments to yourself, and tells you how many transactions the move takes. You never need to do anything about it.

#Keep it safe

• Sign the account message only on opacus.tech. Wallets show which site asks for a signature. A site that asks you to sign the Opacus message is asking for the key to your account.
• Your wallet is your account. Whoever controls your wallet can open your Opacus account. Keep your wallet's seed phrase as safe as you always would.

#If you lose your device

Open the app on another device with the same wallet, and sign. Your balance, history and links are all there: the app reads them from the pool itself. People kept by name and bills split live in the browser where you made them, and do not follow you.