Sweep and refund
How approve and reject move funds on-chain, where the fee applies, and who pays gas.
Settlement and refund are executed on-chain by an ephemeral, one-shot proxy at the deposit address. Tekmerion relays a merchant-signed authorization; the blockchain performs the transfer. Tekmerion never holds keys that can move merchant or customer funds, and no proxy exists at the deposit address until the moment a transfer is executed.
Both paths follow the merchant's compliance decision.
Approve — sweep
On a merchant approve carrying a sweep destination (sweep_to), the proxy is deployed at the deposit address, transfers the deposited balance — net of the protocol fee — to sweep_to, collects the protocol fee on-chain in the same transaction, and self-destructs. The resulting finality_outcome is paid and the payment status projects to PAID.
Reject — refund
On a merchant reject carrying a refund destination (refund_to), the proxy transfers the deposited balance — net of the protocol fee — to refund_to, collects the protocol fee on-chain, and self-destructs. The protocol fee applies to a merchant-directed refund just as it does to a sweep: it compensates the infrastructure used to process the payment, not the outcome. The resulting finality_outcome is refunded and the status projects to REFUNDED.
Sanctions hold — funds held, fee zero
When the source address matches the sanctions list, no transfer is relayed. The deposited funds remain at the deposit address, no proxy is deployed, and no fee is taken. A refund occurs only if a refund destination is supplied manually under operational review; in that case the full deposited amount is returned to refund_to with no fee deducted. Tekmerion does not return funds to a sanctioned address automatically. The screening that produces this path is described in Compliance pipeline.
The destination whitelist
Every sweep and refund target — sweep_to and refund_to alike — MUST belong to the merchant's signed destination whitelist. A target outside the whitelist is rejected on-chain; funds can only ever move to a destination the merchant has pre-authorized by signature.
Gas and fees
Tekmerion relays every sweep and refund and bears the gas cost.
The protocol fee is collected on-chain — at settlement, and at a merchant-reject refund. It is zero on the sanctions-hold path. Fee rates are published on the Fees reference page.