Use when a contract deploy, test suite or CI job needs more Sepolia gas than a faucet gives: one x402 call, no faucet login or mainnet history. Input: to (recipient address); sends 1 SepETH. Output: JSON txHash (confirmed before settling), explorerUrl, amountEth, from, to. Daily limits (UTC): 5 SepETH per address (both sizes), 20 overall; checked before payment. Test ETH has no monetary value. Example: ?to=0x000000000000000000000000000000000000dEaD