With #109193 users can provide Date_Period or Time_Duration intervals in EsqlQueryRequest params by casting them to the desired types, here is an example,

{
 "query": "from sample_data | stats var0 = AVG(event.duration) by BUCKET(@timestamp, ?interval::time_duration)",
 "params": [
  {
   "interval": "1 minute"
  }
 ]
}

The goal of this issue is to do implicit casting from string literals to Date_Period or Time_Duration, so that users don't have to convert them explicitly, like the examples below.

{
 "query": "from sample_data | stats var0 = AVG(event.duration) by BUCKET(@timestamp, ?interval)",
 "params": [
  {
   "interval": "1 minute"
  }
 ]
}

There are some other places that Date_Period or Time_Duration intervals can be used besides BUCKET, like datetime +/- intervals, we will try to make it work also, more examples will be added.