Definition
Gas Fees
The transaction fees paid to blockchain validators for processing on-chain operations like USDC transfers.
Gas fees are the costs of executing transactions on a blockchain. Every on-chain operation (transferring USDC, interacting with smart contracts) requires computational work from validators, who charge fees for this service. Gas fees vary dramatically by chain: Ethereum mainnet can charge $2-50+ per transaction, while Layer 2 chains like Base and Polygon charge less than $0.001. For x402 micro-transactions to be economically viable, low gas fees are essential — you can't pay $0.01 for an API call if the gas fee is $5. This is why Mithril defaults to Base.
Related terms
On-Chain Settlement
The process of recording and finalizing a payment transaction on a blockchain, providing immutable proof of payment.
Base
A Layer 2 blockchain built on Ethereum by Coinbase, offering low fees and fast settlement — the default chain for Mithril payments.
Micro-Transaction
A very small financial transaction, typically under $1, enabled by low-fee blockchain networks for pay-per-call API pricing.