> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/integrations/builtin/credentials/customerio.md).

# Customer.io credentials

You can use these credentials to authenticate the following nodes with Customer.io.

* [Customer.io](/integrations/builtin/app-nodes/n8n-nodes-base.customerio.md)
* [Customer.io Trigger](/integrations/builtin/trigger-nodes/n8n-nodes-base.customeriotrigger.md)

## Prerequisites <a href="#prerequisites" id="prerequisites"></a>

Create a [Customer.io](https://customer.io/) account.

## Supported authentication methods <a href="#supported-authentication-methods" id="supported-authentication-methods"></a>

* API Key

## Related resources <a href="#related-resources" id="related-resources"></a>

Refer to [Customer.io's summary API documentation](https://customer.io/docs/api/?api=journeys) for more information about the service.

For detailed API reference documentation for each API, refer to the [Track API documentation](https://customer.io/docs/api/track/) and the [App API documentation](https://customer.io/docs/api/app/).

## Using API key <a href="#using-api-key" id="using-api-key"></a>

To configure this credential, you'll need:

* A **Tracking API Key**: For use with the [Track API](https://customer.io/docs/api/track/) at `https://track.customer.io/api/v1/`. See the FAQs below for more details.
* Your **Region**: Customer.io uses different API subdomains depending on the region you select. Options include:
  * **Global region**: Keeps the default URLs for both APIs; for use in all non-EU countries/regions.
  * **EU region**: Adjusts the Track API subdomain to `track-eu` and the App API subdomain to `api-eu`; only use this if you are in the EU.
* A **Tracking Site ID**: Required with your **Tracking API Key**
* An **App API Key**: For use with the [App API](https://customer.io/docs/api/app/) at `https://api.customer.io/v1/api/`. See the FAQs below for more details.

Refer to the [Customer.io Finding and managing your API credentials documentation](https://customer.io/docs/accounts-and-workspaces/managing-credentials/) for instructions on creating both Tracking API and App API keys.

## Why you need a Tracking API Key and an App API Key <a href="#why-you-need-a-tracking-api-key-and-an-app-api-key" id="why-you-need-a-tracking-api-key-and-an-app-api-key"></a>

Customer.io has two different API endpoints and generates and stores the keys for each slightly differently:

* The [Track API](https://customer.io/docs/api/track/) at `https://track.customer.io/api/v1/`
* The [App API](https://customer.io/docs/api/app/) at `https://api.customer.io/v1/api/`

The Track API requires a Tracking Site ID; the App API doesn't.

Based on the operation you want to perform, n8n uses the correct API key and its corresponding endpoint.