---
title: assembler bloom-filter create
description: Generates a bloom filter that gets embedded into the docs-builder binary. This bloom filter is used to determine whether a document's mapped_page in the...
url: https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/2862/cli/assembler/assembler-bloom-filter-create
---

# assembler bloom-filter create
Generates a bloom filter that gets embedded into the `docs-builder` binary.
This bloom filter is used to determine whether a document's `mapped_page` in the frontmatter exists in
the project of [legacy-url-mappings](https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/2862/configure/site/legacy-url-mappings)
The existence determines how the document history selector should be populated.

## Usage

```
docs-builder assembler bloom-filter create [options...] [-h|--help] [--version]
```


## Options

<definitions>
  <definition term="--built-docs-dir <string>">
    The local dir of local elastic/built-docs repository (Required)
  </definition>
</definitions>