What's under
the hood?

BIM is a minimalist wallet to pay and receive in bitcoin, built on Starknet. BIM is seedless: it uses passkeys to authenticate users, so there is no seed phrase to back up.

Learn more about Starknet.

Using Bitcoin as money for day to day payment is historically difficult because of network constraints and complexity.

Bitcoin doesn't allow for instant transfers required for day to day payments.
Lightning does, but non-custodial Lightning wallets means managing liquidity in channels, which often creates poor UX and/or recurring L1 fees.
Both Bitcoin and Lightning don't support passkeys signature scheme.

BIM takes a new path: a smart-contract wallet on Starknet, unlocked by WebAuthn / passkeys (the same biometric auth your phone and browser already speak). The cryptographic heavy lifting happens inside the Starknet account contract; the user only has to touch a fingerprint sensor.

Three Bitcoin enthusiasts and tech lovers.

You would no longer be able to access your funds through BIM (and neither would we).

To mitigate that:

Use BIM as a payment wallet, not as a vault. If you receive a large amount, transfer it to a safer long-term wallet. Just like your real-world wallet, don't store all your money in it.

BIM's code is source-available, which means that if we ever stop operating the service, anyone could fork it and run their own instance.

A flat 0.3% on every sending transaction. That's it.

No. BIM focuses on Bitcoin transactions only and does not deal with fiat currencies. You need to top up your BIM wallet from another wallet that already holds bitcoin.

BIM does not let you trade fiat for bitcoin directly, so you first need to top up your BIM wallet from another Bitcoin wallet you own (Ledger, Phoenix, Braavos, etc.).

To top up:

1. Open BIM and create a receive invoice.
2. Pay that invoice from your other wallet.
3. Once your BIM balance is positive, you can start making payments.

On Starknet, there is no minimum. Lightning payments require a 1,000 sats minimum, and on-chain Bitcoin payments require a variable minimum (typically around 10,000 sats) to cover swap and network fees.

Payments are pseudonymous: we don't know who you are, but transfers are recorded in clear on the blockchain. We are actively looking into ways to improve this.

No. Once you sign a transaction it is broadcast and irreversible.

Not much, unless you backed up your passkey beforehand. This is why we strongly recommend using BIM as a day-to-day wallet rather than a long-term vault.

Think of a passkey as a digital key stored on your phone or computer that replaces your password entirely. Instead of typing a long string of letters and numbers that you'll probably forget, you unlock your accounts the same way you unlock your phone: with your face (FaceID), fingerprint, or screen PIN.

BIM uses this technology to secure account sign-in and transaction signatures.

You can use password managers such as KeePass, Bitwarden, 1Password or ProtonPass to back up your passkeys.

BIM needs a reliable connection to work properly. Make sure your Wi-Fi or 4G/5G connection is stable and well configured, then try again.

Reach out to us for any inquiries at contact@bitcoinismoney.app.