# `extends`

## Introduction

Use the `extends` configuration to extend an existing configuration set.
Multiple values are supported, and can include:

- the name of a [built-in ruleset](https://redocly.com/docs/cli/rules#rulesets)
- configuration defined in a [custom plugin](https://redocly.com/docs/cli/custom-plugins)
- a path or URL to another `redocly.yaml` file


Extends is useful if you use a common ruleset across multiple projects.
Define a ruleset in one location, and each project can `extend` it, with or without modification.

Default ruleset: recommended
If there is no `redocly.yaml` configuration file, the [recommended ruleset](https://redocly.com/docs/cli/rules/recommended) is used by default.

## Options

The `extends` configuration is an array of strings.

The array is parsed in the order it is defined, so the later entries in the array overwrite the earlier ones.

## Examples

To get started, try the following example to configure your project to be based on the [minimal ruleset](https://redocly.com/docs/cli/rules/minimal):


```yaml
extends:
 - minimal
```

## Resources

- **[APIs configuration](/docs/realm/config/apis)** - Set per-API configuration options in redocly.yaml for granular control over different API specifications
- **[Rules configuration](/docs/realm/config/rules)** - Define linting rules that work with extends configuration for comprehensive API validation
- **[Extending configuration](https://redocly.com/docs/cli/configuration/extends)** - Detailed documentation and examples for extending configuration with base rulesets and inheritance
- **[Configuration options](/docs/realm/config)** - Explore other project configuration options for comprehensive documentation customization