Gas Fees

Gas fees are the price of getting a transaction executed on a blockchain. Every transaction consumes computational work from the network's validators, and gas is how that work is metered and paid for. The busier the network, the more you pay to get included in the next block.

The term comes from Ethereum, where each operation a transaction performs has a fixed gas cost, and the total fee is gas used multiplied by the going gas price.

Gas is an auction. When demand for block space spikes, fees spike with it — Ethereum mainnet fees have ranged from under a dollar to tens of dollars per transaction depending on congestion.

Layer-2 networks (L2s) change the economics by batching many transactions together and posting them to Ethereum as one. Base, the L2 that x402 payments settle on, inherits Ethereum's security while keeping per-transaction fees at a small fraction of a cent in normal conditions.

A micropayment only makes sense if the fee to move the money is far smaller than the payment itself. Sending $0.01 on Ethereum mainnet could cost a hundred times the payment in gas — the fee swallows the value entirely. This is the core reason per-call API billing never worked on L1 blockchains, and why card networks (with their roughly $0.30 minimum economics) never worked for it either.

On Base, the math inverts: when gas is a fraction of a cent, a $0.01 USDC transfer is overwhelmingly payment rather than overhead. That single change is what makes pay-per-call pricing for MCP servers and APIs economically real.

In an x402 exchange, an agent receives an HTTP 402 response with payment details, its wallet signs the payment, and the transfer settles in USDC on Base in roughly two seconds. The on-chain settlement step is where gas applies — and because it happens on Base, the gas component is negligible relative to even the minimum $0.01 call price.

For sellers on Loomal this means the listed price is effectively what moves: there is no fee structure that quietly makes sub-cent-scale calls unprofitable, and settlement is final with no chargeback window.

Gas fees go to the network for executing the transaction; platform fees go to a marketplace or processor for facilitating the sale. They are independent. A $0.05 tool call on Base incurs near-zero gas, while Loomal's platform fee is 5% on settled transactions — currently waived.