HTTP QUERY method defined in RFC 10008 for complex requests

RFC 10008, published in June 2026, defines the HTTP QUERY method: the query travels in the request body while the method stays safe and idempotent. It combines POST's body with GET's caching and retry guarantees, but requires a Content-Type header and server support.

• QUERY sends the query in the body and remains safe and idempotent like GET
• Servers must return 400 or 415 when Content-Type is missing or mismatched
• Responses are cacheable, with the request body and media type in the cache key
• The Accept-Query header advertises method support and accepted query formats