#4968 (comment)

this is for client side or server side ?
where to add this ?

Root config:

{
  "version": {
    "min": "25.8.3",
    "max": ""
  },
  "log": {},
  "inbounds": [],
  "outbounds": [],
  ...
}

it can be used in both server and client, but its use is to force clients to use specific versions.

,
"max": ""

I've tried but it doesn't work well i use older core client like npv tunnel to check is this can prevent client from connecting because of old core version , but it didn't , i tried this code on costume config for client side + on server side too

This feature added in v25.8.3.
So it doesn't work in older versions.

For older versions you can use new alias
like: direct, tunnel, block(#4968) to force clients use the latest version.