> ## Documentation Index > Fetch the complete documentation index at: https://docs.cloak.ag/llms.txt > Use this file to discover all available pages before exploring further. # What is Cloak? > A privacy layer for Solana — a private, self-custodied balance you can spend from without your wallet appearing as sender Cloak is a privacy layer for Solana: shield funds into a private balance, transact from it privately, and leave whenever you want. It is live on Solana mainnet today, in beta. Shielded pools are like sealed envelopes in a public mailbox: everyone sees mail, not what's inside. ## The problem Everything on Solana is public by default. Anyone with your address can read your balance, your income, your counterparties, and your habits — no subpoena, no hack, no permission needed. [Your wallet is a public diary](/learn/wallet-public-diary), and most people write in it every day. Privacy isn't hiding — it's choosing who gets the receipt. ## What you can do today * **Shield** — move SOL, USDC, or USDT from your wallet into your private balance. Free — no protocol fee; your wallet pays normal network gas. * **Bridge in** — send USDC from Polygon, Ethereum, Base, Arbitrum, or Sui and have it arrive as a private balance, with no public Solana wallet of yours in between. * **Private send** — pay any Solana address or .sol domain from your private balance. On-chain, the funds arrive from the Cloak pool; your wallet never appears as sender. * **Private swap** — swap shielded SOL into any Jupiter-verified token, delivered to the address you choose without linking back to your funding wallet. * **Unshield** — withdraw to your own wallet whenever you want. Same mechanics as a private send, with you as the recipient. Payroll (batch private payouts in USDC or USDT) and single-use [payment links](/guide/payment-links) — pay someone without their address, or get paid without revealing yours — build on the same rails. Under the hood, a zero-knowledge proof generated in your browser — in under three seconds — convinces the chain that each transaction is valid without revealing which funds moved; the plain-language explanation is in [Zero-knowledge without the math](/learn/zero-knowledge-without-the-math). ## What makes Cloak different **Self-custodial, literally.** Your private balance lives encrypted in your UTXOs — private notes only you hold — and your backup file is the money. Cloak can't see your balance, can't spend it, and can't recover it. That's the design. **No gas, no sender trail.** When you act from your private balance, your wallet pays no gas and never appears as sender. Deposits into the pool and payments out of it are both visible on-chain — the link between them isn't. **Auditable when required.** A viewing key lets you disclose your own history — amounts, fees, recipients — to an auditor or counterparty, and can never move funds. Disclosing reveals your transactions only, nothing about anyone else in the pool. Private by default. Auditable when required. **Cheaper to leave.** Shielding is free. Leaving the pool costs 0.3% plus a small fixed fee (0.005 SOL for SOL, 0.45 USDC or USDT for the stablecoin pools) — other Solana privacy protocols charge a flat 1% on every withdrawal. The full who-pays-what table is in [Fees](/guide/fees). **Screened before broadcast.** Every transaction is screened against sanctions and high-risk lists before it goes out — invisible on the happy path. ## Who it's for * **Individuals** — get paid, save, and spend without publishing your finances to anyone who has your address. * **Teams** — run payroll and treasury payouts without broadcasting salaries or vendor relationships. * **Developers** — build private payments into your own product with the [TypeScript SDK](/sdk/introduction). ## Where Cloak stands today Cloak is live on Solana mainnet, in beta, with \$500K+ in shielded volume and 1,500+ transactions processed on mainnet to date. Cloak's shield-pool program has been independently audited, and the program live on mainnet is built from the audited source — you can [verify the deployed bytecode and proving artifacts yourself](/guide/security#verify-it-yourself). The full report is being prepared for publication and will be linked here. For the threat model and the full list of what Cloak cannot do, see [Security](/guide/security). ## Where next The four flows, step by step — shield, send, swap, unshield. UTXOs, the backup file, and exactly what happens if you lose them. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.