Sources and limits

There is no live price oracle on Arc mainnet: Chainlink on Arc is testnet-only and ships no Automation product at all. Once's own worker reads indexed Arc DEX pool data and checks your condition against it — this is not a third-party oracle, and we say so plainly rather than imply one exists.

When your condition is met, the worker assembles the full trade — a Permit2 authorisation that expires with the trade, plus a swap on Uniswap v4 — behind a single wallet signature request, using EIP-5792's batch-call capability. Arc's own EIP-7702 support means an ordinary wallet address can do this without migrating to a smart account.

UniswapX is non-custodial and already live on Arc mainnet; it is a fair alternative for someone who would rather have a guaranteed fill than zero allowance. Once exists for the person who won't grant either.

As of WalletConnect's own published survey, Safe is the only wallet that has added wallet_sendCalls support over that transport — one-tap batch approval cannot be assumed for an arbitrary mobile wallet. Where it isn't supported, Once falls back to two prompts (approve, then swap), clearly labelled as the degraded path, never hidden as the default.

On iOS, push permission cannot even be requested until the app has been added to the Home Screen. Once will ask for that step once, up front, rather than silently failing to wake you later.