Independent x402 is an application-level protocol for internet-native payments built on the HTTP 402 (Payment Required) status code. This document defines how a domain publishes its x402 payment capability out-of- band, so that clients, autonomous agents, and indexers can discover it without prior configuration or a central directory. It specifies a JSON capability manifest served at the well-known URI "/.well- known/x402" and an optional DNS TXT record at the underscored node name "_x402" that points to the manifest. A consumer resolves a bare domain name to verified x402 capability with at most one DNS query and one HTTPS GET.