---
title: assembler.yml
description: The assembler.yml file defines the global documentation site: environments.shared_configuration.narrative repository configuration.reference repository...
url: https://docs-v3-preview.elastic.dev/docs-builder/documentation/assembler/configure
products:
  - Elastic Docs Builder
---

# assembler.yml
The [`assembler.yml`](https://github.com/elastic/docs-builder/blob/main/config/assembler.yml) file defines the global documentation site:
- `environments`.
- `shared_configuration`.
- narrative repository configuration.
- reference repository configurations.


## `environments`

This section defines different build environments for the documentation site.
Each environment specifies configuration details such as the site URI, content source, path prefix, Google Tag Manager settings, and feature flags.
Example:
```yml
environments:
  prod:
    uri: https://www.elastic.co
    path_prefix: docs
    content_source: current
    allow_indexing: true
    google_tag_manager:
      enabled: true
      id: GTM-KNJMG2M
```


## `shared_configuration`

This section defines YAML anchors for common settings shared among multiple repositories and deployment environments.
The following example sets a unique `stack` version for each of the three defined deployment environments:
```yml
  stack: &stack
    current:  9.0
    next: 9.1
    edge: main
```


## `narrative`

Configures the main `docs-content` repository.
Example:
```yml
narrative:
  checkout_strategy: full
```


## `references`

Configures all other repositories whose docs content should be included or referenced in the build. Each can have custom settings for branch, checkout method, etc.
Example:
```yml
references:
  apm-server:
```


### Branching strategy

How you add a reference repository depends on its [branching strategy](/docs-builder/documentation/assembler/environments#branching-strategies).

#### Continuous deployment repository

To add a continuous deployment repository, define the name of the repository:
```yaml
references:
  my-repository:
```

The above configuration is equivalent to specifying.
```yaml
references:
  my-repository:
    next: main
    current: main
```


### Tagged repository

To add a tagged repository, configure the repo to have a fixed git reference (typically a branch) deploy the `current` content source to production.
```yaml
references:
  my-other-repository:
    next: main
    current: 9.0
```