Executable EVM swap quote (ready-to-sign tx), paid per call via x402

Firm KyberSwap-routed quote plus a ready-to-sign transaction for the taker's own wallet - non-custodial, no key, no account. Query params: chainId, sellToken and buyToken ('native' or a 0x 40-hex address), sellAmount (integer, base units), taker (0x address), optional ref (referrer 0x address). The returned transaction includes a 1% platform fee in the chain's native coin, on top of the swap. Bad params answer 400 before any payment starts; no-route and upstream errors pass through as 4xx/5xx and are never settled.