The HTTP QUERY Method (RFC 10008)

RFC 10008 defines QUERY, an HTTP method that is safe and idempotent like GET but carries a request body like POST. It exists for the operation every API eventually needs and no existing method fits — a read whose parameters are too large or too structured for a URL. Because it is safe, a QUERY response is cacheable and a QUERY request may be automatically retried, neither of which is true of the POST /…/search workaround it replaces. It also registers the Accept-Query response header, through which a resource advertises that it accepts QUERY and which query media types it understands.