> ## Documentation Index > Fetch the complete documentation index at: https://second.tech/docs/llms.txt > Use this file to discover all available pages before exploring further. # Overview Bark Wallet is a self-custodial wallet app that sends and receives bitcoin over Ark, Lightning, and on-chain. It runs on your own hardware: install it from the Umbrel App Store or the Start9 Registry, or self-host it with Docker, then open it in your browser and start making payments. Screenshot of the Bark Wallet dashboard, with the main balance, its off-chain and on-chain sub-balances, the next round countdown, and the payment history ## One balance, every payment network Your bitcoin lives in your Ark balance, and you spend it over Ark, Lightning, or on-chain: * **Pays to anything:** Ark addresses, on-chain addresses, BOLT11 invoices, BOLT12 offers, Lightning addresses, LNURL, and BIP-321 payment links. * **One receive code:** A single QR code combines your Ark, Lightning, and on-chain payment details, and the sender's app picks the cheapest option it supports. * **Free Ark payments:** Sends to another wallet app on the same Ark server cost nothing, down to a single sat. * **Wallet maintenance:** Bark Wallet handles all required maintenance tasks (e.g., [refreshes](/docs/learn/rounds)) in the background for you. * **Emergency exit:** Move your balance back on-chain at any time, [even if the Ark server is offline](/docs/learn/exit). * **Branta-verified recipients:** When a recipient registers with [Branta](https://branta.pro), the wallet app confirms the payment details before you send. ## Barkd under the hood Bark Wallet packages [Barkd](/docs/barkd), Second's wallet daemon, with a web interface (bark-web). Barkd holds your keys on your own device and connects to Second's Ark server, which coordinates rounds and handles Lightning connectivity. Your bitcoin stays under your control. The app is open source under the MIT license, built as a reference implementation: if you're building a wallet app on Barkd, the [bark-web repository](https://gitlab.com/ark-bitcoin/labs/bark-web) shows how Second's own team approached it, UX decisions included. ## Set up and use Bark Wallet One click from the Umbrel App Store or the Start9 Registry, or self-host with Docker. Write down your seed phrase, and keep a continuous copy of your wallet data. How to read your main balance and its sub-balances, and your payment history. Pay any address or invoice, and receive over Ark, Lightning, or on-chain. Inspect the VTXOs behind your balance, and refresh, offboard, or exit them manually. Display preferences, refresh behavior, your seed phrase, and the emergency exit. Open the wallet app while you're away from home. Bring a wallet back from a continuous backup or from your seed phrase. Keep the app up to date, or remove it safely after emptying the wallet.