---
title: Sharing Configuration
description: Learn how to share and reuse configuration pieces in your configuration.
---

In Mergify, you can leverage certain features like YAML anchors and aliases,
the `shared` key, and the `extends` key to reduce redundancy, maintain
consistency, and increase code reusability.

## YAML Anchors and Aliases

[YAML anchors (`&`) and aliases
(`*`)](https://yaml.org/spec/1.2.2/#anchors-and-aliases) are supported in the
[configuration file](/configuration/file-format). These allow you to reuse
configuration sections. For example, you can create a list of continuous
integration checks and use it in multiple sections:

```yaml
queue_rules:
  - name: hotfix
    queue_conditions:
      - and: &CheckRuns
        - check-success = linters
        - check-success = unit
        - check-success = functionnal
        - check-success = e2e
        - check-success = docker
  - name: default
    queue_conditions:
      - and: *CheckRuns
      - schedule = Mon-Fri 09:00-17:30[Europe/Paris]
```

## Sharing Configuration Sections

You can store anything in the `shared` key. Its main purpose is to provide a
place to put redundant YAML anchors:

```yaml
shared:
  my_ci: &common_checks
    - check-success = ci-one
    - check-success = ci-two

queue_rules:
  - name: hotfix
    queue_conditions:
      - and: *my_ci
  - name: default
    queue_conditions:
      - and: *my_ci
      - schedule = Mon-Fri 09:00-17:30[Europe/Paris]
```

## Extending Configuration Files

Mergify lets you extend your configuration file by including the configuration
from another repository. This feature is useful when you want to share and
reuse configuration rules across multiple repositories, helping maintain
consistency and reduce duplication.

To extend a configuration file, use the `extends` keyword at the top level of
your configuration file file and specify the repository name from which you
want to include the configuration.

```yaml
extends: shared-config
```

:::caution
  The Mergify application must also be installed on the source repository
  that you want to import the configuration from.
:::

The configuration from the specified repository will be loaded and applied
before the one in the current repository. Here's an example:

```yaml
extends: shared-config

pull_request_rules:
  - name: additional rule specific to this repository
    conditions:
      - base = main
    actions:
      label:
        add:
          - repository-specific
```

:::caution
  - Values in the `shared` key will not be merged and shared between local and
    remote configurations.

  - Values in the `defaults` and `commands_restrictions` key will be merged and remote default
    values will apply to local configuration, unless a same default value already exist in the
    local configuration.

  - Rules in the `pull_request_rules`, `queue_rules`, `priority_rules` or
    `merge_protections` section will be merged and remote default values will
    apply to local configuration. A rule will not be overwritten, by the
    extended configuration, if it has the same name in both the extended and
    local configuration. :::