Correct syntax for adding a filter aggregation in a Kibana visualization as a JSON input (filtering for a specific property value)

Question

I am trying to perform the simplest filter for a specific property value, as a JSON input, in a Kibana visualization, thoroughly without success.

I can't, to my surprise, find concrete examples in doing that (have been searching for a couple of minutes now).

Say we have a document with the following structure:

{
    a: true,
    b: 10
}

How can I add a Filter aggregation for all documents with a = true ?

I tried using "script", "query", "filters" api, but all give me parse errors. My filter jsons are all valid, my problem is with the exact syntax elastic is expecting, but all examples I found out there and tried - give me parsing errors (after making the amendments to my index structure).

Kibana's version: 6.4.3

How is this accomplished ?

Answer 1

An example:

POST /sales/_search?size=0
{
    "aggs" : {
        "docs" : {
            "filter" : { "term": { "a": "true" } },
        }
    }
}

Here is the link to the official documentation with example.