x402 API Key + URL Packs: Api Codex Key Pack 50
https://x402-key.558686.xyz/v1/paid/api-codex-key-pack-50Overview
URL + Key pack with $50 quota. Standalone x402 URL + Key quota pack checkout with a $0.001 URL readiness check and a $1 quota key trial pack priced at $0.12. Buyers can download the route-specific first-payment client at https://x402-key.558686.xyz/x402/route/api-codex-key-pack-50/first-payment-client.mjs, run node first-payment-client.mjs for quote-only checks, then opt into a buyer-owned x402 payment with PAY_REAL_X402=1. Generic clients can also discover it from the live 402 response headers: X-First-Payment-Client and Link rel=payment-client.