# Fee Management

## Message Fees

Proto-USD uses a static fee model of **0.25 USDC per hop**, regardless of the transfer amount (e.g., whether the user sends $20 or $200,000). This fee is fully automated and abstracted. The implementing party does not pay message fees.

## Gas Fees (Mainnet)

**NOTE: ONLY PERTAINS TO INTEGRATING BLOCKCHAIN FOUNDATIONS**

Gas fees are required on the destination chain to automatically relay cross-chain messages. These fees are paid using the wrapped native gas token (e.g., WETH on Ethereum, WAVAX on Avalanche) within the `BridgedManagerV1` contracts. To ensure the successful completion of transfers, the blockchain foundation / team is responsible for managing the destination [gas reimbursement mechanism](https://docs.vialabs.io/supported-protocols/proto-usd/gas-reimbursement-mechanism). The Bridged Manager contracts **must maintain sufficient wrapped gas tokens** to support the automatic relaying of messages.

On chains with infinitesimally low gas fees, protocols often choose to sponsor this fee. However, on networks like Ethereum, gas fees can accumulate quickly.

## Gas Fees (Testnet)

VIA Labs sponsors all gas on testnet.  New implementing blockchains are asked to provide testnet tokens.