Ark Wallets

1. Your balance is made of VTXOs. Instead of ordinary on-chain outputs, an Ark wallet holds VTXOs (virtual UTXOs). A VTXO is a Bitcoin output that hasn’t been published on-chain yet but could be, at any time, using transactions you already hold, signed in advance.

2. Many users share one on-chain transaction. An operator groups users’ funds into shared on-chain outputs. Because the cost of that one transaction is split across everyone in it, each person’s share of the fee is small.

3. Payments happen off-chain. When you pay someone on Ark, the payment moves between wallets without waiting for a block. It is typically instant, and it doesn’t need the receiver to have a channel or to be online with a node.

4. Wallets refresh their coins. VTXOs have a built-in lifetime, roughly 30 days on current mainnet deployments. Before they expire, your wallet swaps them for fresh ones in a coordinated round. Good wallets do this automatically, so you rarely think about it.

5. You can always exit.

• Cooperative exit: Withdraw to any on-chain address through the operator. This is the normal, fast route.
• Unilateral exit: If the operator is offline or uncooperative, broadcast your pre-signed transactions and claim your bitcoin on-chain yourself. It costs on-chain fees and takes longer, but it doesn’t need anyone’s permission.

6. Lightning works too. Ark wallets connect to Lightning through the operator, so you can pay invoices from your Ark balance without managing a channel yourself.

An Ark operator is the service that runs an Ark network. Think of it as the coordinator that makes shared on-chain transactions possible.

What an operator does:

• Gathers users’ funds into shared on-chain transactions and runs the periodic rounds in which coins are refreshed
• Co-signs payments so they are valid and can’t be double-spent
• Provides the liquidity that makes instant payments possible, so you don’t have to
• Handles on-chain exits and bridges payments to Lightning

What an operator can’t do:

• Spend your coins without your signature
• Remove the pre-signed exit path built into your VTXOs

What that means for you: the operator is a service you rely on for speed and convenience, not a custodian you have to trust with your funds. If it disappears, you can still exit unilaterally.

Different operators, different networks. Ark has more than one implementation, including Second’s Bark and Ark Labs’ Arkade, and each runs its own operator and network. A wallet connects to a specific operator, so check which one yours uses. Payments between networks generally travel over Lightning.

Why Choose an Ark Wallet?

We want you to use Ark wallets with open eyes.

• You rely on the operator for day-to-day use. If it goes offline, you can still withdraw, but unilateral exits cost fees and take time.
• Coins need refreshing. A wallet that stays offline for too long can miss its refresh window. Use a wallet that handles renewals for you, and open it regularly.
• Very small balances are harder to exit. Amounts below roughly 330 sats can’t be redeemed on-chain by themselves, so they are not protected if the operator disappears.
• Back up your recovery phrase and wallet data.
• This is new technology. Ark launched on mainnet in 2025 and 2026. Start with an amount you are comfortable losing, and increase it as you learn.