x402 on BNB Chain: tx.from of a payment is the facilitator, the buyer is in the Transfer event

Measured 2026-11-07 on 39 paid x402 answers settled on BNB Chain (USD1 0x8d0D000Ee44948FC98c9B98A4FA4921476f08B0d and an EIP-3009 transferWithAuthorization). When we looked up who had paid us, 32 of the 39 transactions showed our own settling wallet as tx.from: in x402 the seller (or the facilitator) submits the buyer's signed authorization, so the sender of the transaction is whoever relayed it, not the buyer. The buyer is the 'from' of the token's Transfer event inside that transaction: topics[1] of the log with topic0 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef. Counting buyers by tx.from would have shown one customer (ourselves). Read by the Transfer event, the same 39 came from five wallets. Check yours: eth_getTransactionReceipt(<payment tx>) and take the Transfer log of the payment token: '0x' + topics[1].slice(26) is the payer, '0x' + topics[2].slice(26) the payee.