Wallet
One word for several different things. Which one you mean decides what the screen has to say.
The most overloaded word in this guide. Somebody downloads a wallet, creates a wallet inside it, then connects a wallet to an app.
Do
Decide which sense you mean before writing the screen. "Create a wallet" and "Connect your wallet" are different enough that a user who confuses them will do the wrong thing.
The wallet, as data
Everything derived from and associated with one set of keys: the keys themselves, the outputs they control, the proofs for those outputs, the Passes the user holds, and the labels they added.
Why this definition matters on BSV
A BSV wallet holds data no public index can give back, which is why a backup has two parts and why "I have my words" is not the same as "I can restore".
See Backup and recovery.
The wallet application
The software a person downloads and opens. It manages one or more wallets, draws the screens, and answers requests from apps.
On screen, a person installs a wallet, not a "wallet application". Keep the longer phrase for your own documentation.
Derived keys
Keys are not stored one by one. They are produced from a single secret, so a backup of that secret covers every key the wallet will ever use.
A modern BSV wallet derives every key from one master key, per payment, with the other party: payer and payee each derive a key for this payment from a shared secret and an invoice number, so no two payments reuse a key. Older wallets used a tree of keys instead; importing one is a legacy route.
Do
Leave key derivation out of the interface. A user never needs the word "derivation"; they need to know that one backup covers everything.
Connected wallet
A wallet an app can ask for a payment, a signature or a Pass, through the connection standard. The app never sees a key, and the wallet decides every request.
Don't
Call this "a BRC-100 wallet". The number names a document, not a product. In an interface the string is Connect wallet.
See Connecting a wallet.
Custodial and non-custodial
Custodial: a service holds the keys and the user signs in with an account. Convenient, recoverable by support, and the service can freeze or lose the funds.
Non-custodial: the keys are the user's. Nothing moves without them, and nobody can restore their access if they lose their recovery words or their wallet backup. This guide assumes non-custodial throughout.
Do
Say which one you are, in plain words, before the user has anything to lose. "We cannot reset this for you" is the sentence that matters, not the word "non-custodial".
Hot and cold
Whether the keys are on something connected to a network.
Hot: a phone or a laptop. Convenient, and exposed to whatever reaches the device.
Cold: a device that never connects. Signing happens by carrying the transaction and its proofs across by QR, file or card.
A common setup uses both, with everyday money hot and savings cold. See Wallet setups.
Watch-only
A view of a wallet's balance and history with no ability to spend. On BSV it needs a copy of the wallet records, because with a fresh key for every payment a public key alone cannot show a balance.
Useful for an accountant, a co-owner, or a beneficiary who should be able to see without being able to act.
Single-key and multi-key
Single-key: one key authorises a payment.
Multi-key: several keys do, with a rule like two of three. On BSV the conditions sit in the output itself and are therefore public, which is a design consideration rather than a technical obstacle.
See Multi-key and Shared wallet.
Account
A division inside one wallet, under the same backup. Useful for separating business from personal, or one project from another.
Don't
Use "account" for the thing a user signs into. If your product has both, one of them needs a different word.
Related
Written from: BRC-42, BRC-43, BRC-75, BRC-100.
Checklist
The rules on this page, in a form you can work through.
5 rules