elasticsearch/docs/reference/text-analysis/analysis-predicatefilter-tokenfilter.md

---

navigation_title: "Predicate script" mapped_pages:

• https://www.elastic.co/guide/en/elasticsearch/reference/current/analysis-predicatefilter-tokenfilter.html ---

Predicate script token filter [analysis-predicatefilter-tokenfilter]

Removes tokens that don’t match a provided predicate script. The filter supports inline Painless scripts only. Scripts are evaluated in the analysis predicate context.

Example [analysis-predicatefilter-tokenfilter-analyze-ex]

The following analyze API request uses the predicate_token_filter filter to only output tokens longer than three characters from the fox jumps the lazy dog.

GET /_analyze
{
  "tokenizer": "whitespace",
  "filter": [
    {
      "type": "predicate_token_filter",
      "script": {
        "source": """
          token.term.length() > 3
        """
      }
    }
  ],
  "text": "the fox jumps the lazy dog"
}

The filter produces the following tokens.

[ jumps, lazy ]

The API response contains the position and offsets of each output token. Note the predicate_token_filter filter does not change the tokens' original positions or offsets.

::::{dropdown} Response

{
  "tokens" : [
    {
      "token" : "jumps",
      "start_offset" : 8,
      "end_offset" : 13,
      "type" : "word",
      "position" : 2
    },
    {
      "token" : "lazy",
      "start_offset" : 18,
      "end_offset" : 22,
      "type" : "word",
      "position" : 4
    }
  ]
}

::::

Configurable parameters [analysis-predicatefilter-tokenfilter-configure-parms]

script : (Required, script object) Script containing a condition used to filter incoming tokens. Only tokens that match this script are included in the output.

This parameter supports inline [Painless](/reference/scripting-languages/painless/painless.md) scripts only. The script is evaluated in the [analysis predicate context](/reference/scripting-languages/painless/painless-analysis-predicate-context.md).

Customize and add to an analyzer [analysis-predicatefilter-tokenfilter-customize]

To customize the predicate_token_filter filter, duplicate it to create the basis for a new custom token filter. You can modify the filter using its configurable parameters.

The following create index API request configures a new custom analyzer using a custom predicate_token_filter filter, my_script_filter.

The my_script_filter filter removes tokens with of any type other than ALPHANUM.

PUT /my-index-000001
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "standard",
          "filter": [
            "my_script_filter"
          ]
        }
      },
      "filter": {
        "my_script_filter": {
          "type": "predicate_token_filter",
          "script": {
            "source": """
              token.type.contains("ALPHANUM")
            """
          }
        }
      }
    }
  }
}