The server needs to know what to do with them. Since I am only writing a client here, I can't do the server-side piece of the preflight checks etc Also the ser

The server needs to know what to do with them. Since I am only writing a client here, I can't do the server-side piece of the preflight checks etc Also the service needs to have a particular user-agent to work, so the proxy doubles up as a rewriter for that.