Paid: what changed in a company's latest SEC filing. $0.10 USDC on Base (x402 v2, exact). An unpaid call returns JSON-RPC error 402 whose data is the x402 PaymentRequired (also base64 in data.payment_required and the PAYMENT-REQUIRED header). Pay by retrying the same tools/call with the PaymentPayload in params._meta["x402/payment"], or with header PAYMENT-SIGNATURE: . The receipt comes back in result._meta["x402/payment-response"] and the PAYMENT-RESPONSE header. Tickers: AMD, MRVL, NVDA, AVGO, TSM, MU, AMAT, AAPL, MSFT, META, TSLA, ORCL, INTC, ASML, MSTR, JPM, BAC. Others return 404 (no charge).