# Getting Started with External Catalogs

The how-to guides linked on this page illustrate how to link [an external catalog with Immuta](https://documentation.immuta.com/2024.2/data-and-integrations/catalogs/reference-guides/pre-configuration) to ingest tags.

{% hint style="info" %}
**Best practice:** Use a single catalog; having more than one can lead to multiple truths and data leaks.
{% endhint %}

## Link an Alation external catalog

**Requirement**: A catalog with tags that correspond to your Immuta data sources

### Configuration process

1. [Connect your Alation catalog to Immuta](https://documentation.immuta.com/2024.2/data-and-integrations/configure#link-an-alation-catalog).
2. When changes are made to the external catalog, [refresh external tags](https://documentation.immuta.com/2024.2/tags/how-to-guides/managing-tags#import-tags-from-an-external-catalog).

## Link a Collibra external catalog

**Requirements**:

* A physical data dictionary with assets that correspond to your Immuta data sources
* The Collibra global role `Catalog` or `Catalog Author`

### Configuration process

1. [Connect your Collibra catalog to Immuta](https://documentation.immuta.com/2024.2/data-and-integrations/configure#link-a-collibra-catalog).
2. When changes are made to the external catalog, [refresh external tags](https://documentation.immuta.com/2024.2/tags/how-to-guides/managing-tags#import-tags-from-an-external-catalog).

## Link a custom REST catalog

**Requirements**:

* A catalog with tags that correspond to your Immuta data sources
* [Authenticate with the Immuta API](https://documentation.immuta.com/2024.2/developer-guides/api-intro/immuta-v1-api/authentication)

### Configuration process

1. [Connect your custom REST Catalog to Immuta](https://documentation.immuta.com/2024.2/data-and-integrations/configure#link-a-custom-rest-catalog).
2. When changes are made to the external catalog, [refresh external tags](https://documentation.immuta.com/2024.2/tags/how-to-guides/managing-tags#link-an-external-catalog-to-a-data-source).

## Link Snowflake for tag ingestion

**Requirements**:

* A Snowflake user who can set the following permissions:
  1. `GRANT IMPORTED PRIVILEGES ON DATABASE snowflake`
  2. `GRANT APPLY TAG ON ACCOUNT`
* Snowflake Enterprise Edition or higher

### Configuration process

1. Configure Snowflake tag ingestion to Immuta.
2. When changes are made to the tags in Snowflake, [refresh external tags](https://documentation.immuta.com/2024.2/tags/how-to-guides/managing-tags#import-tags-from-an-external-catalog)