This is an experimental feature and is not recommended for use in a production environment. For updates on the progress of the feature or if you want to leave feedback, join the discussion in the [OpenSearch forum](https://forum.opensearch.org/t/rfc-search-pipelines/12099).
The `script` search request processor intercepts a search request and adds an inline Painless script that is run on incoming requests. The script can only run on the following request fields:
-`from`
-`size`
-`explain`
-`version`
-`seq_no_primary_term`
-`track_scores`
-`track_total_hits`
-`min_score`
-`terminate_after`
-`profile`
For request field definitions, see [search request fields]({{site.url}}{{site.baseurl}}/api-reference/search#request-body).
## Request fields
The following table lists all available request fields.
Field | Data type | Description
:--- | :--- | :---
`source` | Inline script | The script to run. Required.
`lang` | String | The script language. Optional. Only `painless` is supported.
`tag` | String | The processor's identifier. Optional.
`description` | String | A description of the processor. Optional.
## Example
The following request creates a search pipeline with a `script` request processor. The script limits score explanation to only one document because `explain` is an expensive operation:
```json
PUT /_search/pipeline/explain_one_result
{
"description": "A pipeline to limit the explain operation to one result only",