How a swap works

01

A swap is a trade between two tokens

A swap exchanges one token for another directly from your wallet, for example USDC for ETH. There's no order book and no broker. Smart contracts on the blockchain do the exchange, using pools of tokens that other people have deposited.

Viru asks a routing service (0x on the EVM networks, Jupiter on Solana) to find a route through those pools. It then shows you what you'd receive and asks you to sign.

02

Estimated vs. minimum

Prices move while your transaction travels to the network, so the review screen shows two numbers: an estimate, and the minimum you're guaranteed. If the price moves against you by more than 1%, the swap cancels and you keep what you had. That 1% is called slippage tolerance.

03

Why some swaps need two signatures

Before a swap can take a token from your wallet, you give the swap contract permission. For most tokens on Base, Arbitrum, Optimism and Polygon that's a signature: the first time you sell a token there, a one-time permission for the contract 0x trades through, and every trade after it still needs your own signature for its exact amount.

A token without that kind of signature, and every token on BNB Chain, needs the permission sent from your wallet instead: a small transaction of its own, for exactly the amount you're selling, with its own network fee, before each sale. The screen says which one a trade needs before you sign.

04

Swaps are final

Once confirmed on the blockchain, a swap can't be reversed. Nobody can refund it, including Viru. That's why the review screen exists.