# `extends`

## Introduction

The `extends` configuration entry allows your project configuration to extend an existing configuration set.
Multiple values are supported, and can include:

- the name of a [built-in ruleset](/docs/cli/v2/rules#rulesets)
- configuration defined in a [custom plugin](/docs/cli/v2/custom-plugins)
- a path or URL to another `redocly.yaml` file

Entries that start with `recheck/`, such as `recheck/markdown`, are Recheck presets for [`redocly recheck`](/docs/cli/v2/commands/recheck).
They merge like any other entry, in the order listed: a later entry overrides an earlier one.
Other commands skip them.
A custom plugin cannot use the id `recheck`.

The [`recheck` block](/docs/cli/v2/configuration/reference/recheck) of the file that lists the presets merges on top of them.
The `recheck` command reads the presets in the root `extends` and in the files that the root `extends` lists.
It does not read them from an API's `extends`.
The `lint` command reads no rules from them.

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](/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](/docs/cli/rules/minimal):

```yaml
extends:
  - minimal
```

## Related options

- [apis](/docs/cli/v2/configuration/reference/apis) configuration options allow setting per-API configuration in `redocly.yaml`.
- [rules](/docs/cli/v2/configuration/reference/rules) settings define the linting rules that are used.

## Resources

- Detailed documentation and examples on [extending configuration](/docs/cli/v2/configuration/extends).