Hello,
Redis accepts both a structured protocol, and a simple space-separated tokens protocol (called the inline protocol) that helps sysadmins to avoid a disaster just because they lack a proper redis-cli but are in need to run a Redis command ASAP. Perhaps this proxy is also supporting both forms.
You can do that with any modern enough Redis server:
Escape character is '^]'.
ping
+PONG
set foo bar
+OK
get foo
$3
bar