Can have empty properties mapping?

[Maxwell_Flanders]

I only want to pre-define a field as an object datatype, but i do not know what fields will go in it, they will be added later by various bits of a logstash kv filter. Can i define it like so without errors??

"my-field": {
  "properties": {
          
  }
}

So, an empty properties field, but "my-field" is definitely an object.

[Igor_Motov]

Yes, that should work. Alternatively, you also specify the type as object explicitly:

"my-field": {
  "type": "object"
}