How Xebra moves USDC between chains
Xebra is an interface and a fee contract on top of Circle's Cross-Chain Transfer Protocol (CCTP), the protocol Circle built to move USDC between blockchains without wrapping it.
Burn, attest, mint
- Burn. You send USDC to Circle's contract on the chain you send from, naming the recipient on the other chain. Circle burns it.
- Attest. Circle waits for that chain to finalise the burn, then signs an attestation: a message saying this USDC was burned, for this recipient, on this destination.
- Mint. Circle's Forwarding Service submits the attestation on the destination chain, which mints the same amount of native USDC to the recipient. The Forwarding Service pays the destination's gas and takes its delivery fee out of the amount.
Because the USDC on the destination is minted by Circle itself, it is the same native USDC as anyone else's there, not a bridged copy.
What you sign
- From Stellar, one transaction in Freighter or the LOBSTR extension. Xebra's contract on Stellar takes its fee and hands the burn to Circle in that same transaction, so either both happen or neither does.
- From Arc, two prompts in your EVM wallet: approving the amount, then the transfer itself. Arc charges its gas in USDC, so keep a few cents in the wallet.
How long it takes
Usually a few minutes: the time for the source chain to finalise, for Circle to attest, and for the Forwarding Service to submit the mint. The bridge shows the transfer's progress until the USDC has arrived.
If delivery fails
Nothing is lost. Each transfer names no particular party to complete it, so once Circle has attested the burn, anyone can submit the mint. If the Forwarding Service ever fails, open claim, paste the burn's transaction hash, and submit the mint from your own wallet; you pay that chain's gas. A Standard transfer's attestation never expires.
Recipients on Solana
USDC on Solana is held in a token account that belongs to a wallet. You give the bridge the wallet address; it works out the token account. If the wallet has none yet, Circle opens it during delivery, for a higher delivery fee that the bridge shows before you sign.