Limits

Minter Allowance

The USDC smart contract (or module) on each blockchain specifies a limit for how much USDC can be minted before the limit needs to be increased by the master minter, Circle. This limit is called the "minter allowance" and it is individually set for each authorized minter, such as CCTP.

Minter allowance is decremented each time the authorized minter mints, by the amount of USDC that is minted. A transaction attempting to mint in excess of the minter allowance will fail, but may succeed on a subsequent retry after the minter allowance is reset. Minter allowance can be queried from the USDC contract on EVM-compatible chains using the public minterAllowance function. On Noble, minter allowance can be queried via the fiattokenfactory module minters API.

Per-Message Burn Limit

CCTP defines per-message burn limits. This value is configurable by the CCTP administrator (Circle). This limit prevents the situation where a user burns an amount of USDC on a source chain that could never be minted on a destination chain without increasing minter allowance thresholds. Per-message burn limits can be queried on the TokenMinter contract on EVM-compatible chains, using the public burnLimitsPerMessage mapping. On Noble, per message burn limit can be queried via the cctp module per_message_burn_limits API.