Fees, finality and safety
What it costs, how fast it settles, and how solvency is enforced.
Fees
Bridging to Arc charges an entry fee, taken at deposit. The exact eUSD you receive is shown before you sign. Redeeming back to USDC is free and exactly one for one.
The fee and the minimum amounts can change, so the bridge screen reads them live from the contracts. Check it for the current numbers rather than assuming. Developers can read the same values on-chain; see the integration guide.
Finality and safety
Transfers settle in about a minute. The bridge waits for your deposit or burn to be several blocks deep before acting, so a chain reorganisation cannot lose or duplicate a transfer.
The contracts enforce that the USDC reserve on Base always covers the eUSD supply on Arc, and they cap how much can be minted or released in a single transaction or block. The reserve can only be moved by a publicly visible on-chain migration, which requires deposits and releases to be paused first.
What eUSD is, and is not
eUSD is Envelope's bridged dollar on Arc, backed one for one by USDC held in the Base vault. It is not USDC and it is not issued by Circle. It is redeemable through this bridge for USDC at exactly one for one at any time.