Caddyfile

$YOUR_RELAY_URL {

    #...other stuff

    @websocket {
        header Upgrade websocket
    }
    reverse_proxy @websocket http://127.0.0.1:7777 {
        header_up X-Real-IP {remote_host}
    }

    @nostrJson header Accept application/nostr+json
    reverse_proxy @nostrJson http://127.0.0.1:7777 {
        header_down Content-Type "application/nostr+json; charset=utf-8"
    }

    root * /var/www/html
    file_server

}