permit2AllowanceLimit

The maximum on-chain Permit2 allowance to grant before signing the payment authorization, in the asset's smallest denomination. This field is valid only for the upto (metered) scheme; supplying it for the exact scheme returns a validation error.

When set, the service approves an ERC-20 allowance for this amount before processing the payment. The approval sets, rather than adds to, the wallet's allowance. Set this field only when the wallet needs approving, for example on its first upto payment, to avoid a redundant on-chain transaction. Omit the field to skip allowance handling. This is the default, and the only behavior for the exact scheme.