Skip to main content
CCTP (Cross-Chain Transfer Protocol) is Circle’s canonical way to move USDC between chains: USDC is burned on the source chain and minted natively on the destination, never a wrapped or bridged variant. A-Identity drives it with Circle’s Bridge Kit (CCTPv2), so an agent’s dollars can leave Arc and arrive as real USDC on another chain. This is the second cross-chain rail alongside Circle Gateway. They solve related problems differently: Gateway moves a unified balance via the Forwarding Service; CCTP is the burn-and-mint primitive underneath native USDC liquidity.

​
The burn-and-mint lifecycle

1

approve

The bridge is approved to spend the USDC being moved.
2

burn

USDC is burned on Arc, emitting a cross-chain message.
3

fetchAttestation

Circle attests the burn. Because Arc has instant finality, the attestation is reached fast.
4

mint

Native USDC is minted on the destination chain (Base Sepolia in our demo): the same dollar, no wrapper.
Verified live on Arc testnet: a 1 USDC transfer ran the full approve → burn → fetchAttestation → mint lifecycle in about 15 seconds, each step a real transaction, minting native USDC on Base Sepolia, on both the local and the live production backend. SDK: @circle-fin/bridge-kit.

​
Stellar

Stellar is on this rail too, and it is the one destination that needs its own paragraph. Circle’s Bridge Kit has no Stellar adapter, so mcp/src/cctp-stellar.ts drives the protocol directly: burn, Iris attestation, mint, in both directions.
  • A Stellar recipient must go through Circle’s CctpForwarder. The CCTP message format has no room for a StrKey type marker, so the G... account rides in the hook data and the forwarder mints and forwards in one atomic call. A direct mint to a G... account is unrecoverable.
  • Seven decimals on one side, six on the other. Stellar assets carry 7 decimals and every EVM USDC carries 6, so an amount is converted rather than copied.
  • Testnet-proven both ways on 2026-09-10: Arc testnet to Stellar testnet, and a Stellar testnet burn minted back on Arc. Both legs are on the proof pages.
  • Mainnet is opt-in only. It runs behind CCTP_STELLAR_ALLOW_MAINNET with a single-digit USD cap (CCTP_STELLAR_MAX_USD, default 5), and the hosted deployment carries no CCTP Stellar keys, so production returns a labeled prepared no-op there.
More on the chain itself: Build on Stellar.

​
Gateway vs CCTP

Leaving Arc, the bridged amount must exceed the CCTPv2 max fee: tiny testnet transfers can revert with “Max fee must be less than amount”. The demo defaults to 1 USDC.

Build on Arc

Arc is the primary rail: gas in USDC, sub-second finality. CCTP and Gateway extend it across chains.