CoAP FETCH Method
Similar to HTTP, the existing Constrained Application Protocol (CoAP) GET method only allows the specification of a URI and request parameters in CoAP options, not the transfer of a request payload detailing the request. This leads to some applications to using POST where actually a cacheable, idempotent, safe request is desired. The present proposal adds a new CoAP method, FETCH, to perform the equivalent of a GET with a request body. This specification is inspired by I-D.snell-search-method, which updates the definition and semantics of the HTTP SEARCH request method previously defined by RFC5323. However, there is no intention to limit FETCH to search-type operations, and the resulting properties may not be the same as those of HTTP SEARCH. For now, we therefore prefer to discuss the proposal under a different name, for which we have chosen the GET synonym FETCH.