nginx will proxy the new HTTP QUERY method. It will never cache one.

The IETF recently introduced the HTTP QUERY method via RFC 10008, designed to allow read requests with bodies that are safe, idempotent, and cacheable. While modern clients and language models are increasingly capable of utilizing this method, infrastructure support remains a significant hurdle. Testing reveals that while Nginx successfully proxies QUERY requests to backend servers, it fails to cache them. Nginx's current configuration does not support QUERY in its cache methods, and attempts to rewrite the method to POST for caching purposes are ineffective because Nginx evaluates cache eligibility based on the original client request. Consequently, developers looking to leverage QUERY for its caching benefits face a silent failure where requests bypass the cache entirely. The author concludes that while the protocol is ready for adoption, the middle layer of the web stack requires updates to properly handle the new method's caching requirements.