> ## Documentation Index
> Fetch the complete documentation index at: https://docs.brew.new/llms.txt
> Use this file to discover all available pages before exploring further.

# Customer.io

> Send transactional emails through Customer.io. Connect with your App API key.

Connect your Customer.io account to use it as your email service provider for sending Brew-generated emails directly to your contacts.

<Frame>
  <img src="https://mintcdn.com/brew-796f053a/TkeZeF9b5fooJEh7/images/integrations/CustomerIO_OG.png?fit=max&auto=format&n=TkeZeF9b5fooJEh7&q=85&s=23477527566d3ddf7634c874e04896a1" alt="Customer.io Integration" className="w-full rounded-xl" width="1024" height="571" data-path="images/integrations/CustomerIO_OG.png" />
</Frame>

## Setup

<Steps>
  <Step title="Select your datacenter region">
    In Brew, go to **Integrations** and click the **Customer.io** card. Choose the region where your Customer.io account is hosted: **US (United States)** or **EU (European Union)**.

    <Info>
      Not sure which region you're on? Check your Customer.io dashboard URL. EU accounts use `fly.customer.io` or have `eu` in the URL.
    </Info>
  </Step>

  <Step title="Go to API credentials in Customer.io">
    In Customer.io, navigate to **Settings → Account Settings → API Credentials**.
  </Step>

  <Step title="Paste your App API Key">
    Under **App API Keys**, create a new key, copy it, and paste it into Brew. Click **Connect**.

    <Warning>
      Use an **App API key**, not a Tracking API key. Copy it immediately as you won't be able to view it again later.
    </Warning>
  </Step>
</Steps>

That's it. Customer.io is now connected to Brew.

## Sending Through Customer.io

Once connected, send any email through Customer.io:

1. Open an email you've created in Brew
2. Click **Send**
3. Choose to send through **Customer.io** instead of Brew

You still create and design emails in Brew. They get delivered through your Customer.io account.

## Importing Templates Into Customer.io Design Studio

The Customer.io integration sends emails through your account but doesn't export templates directly into Customer.io. If you want to use a Brew email as a reusable template in Customer.io, you can do this manually via Customer.io's Design Studio.

<Steps>
  <Step title="Export the HTML from Brew">
    In Brew, open the email you want to export. Click the **three-dot menu** and select **Export HTML** to download the HTML file.
  </Step>

  <Step title="Import into Design Studio">
    In Customer.io, go to **Design Studio → Import → Upload** and select the downloaded HTML file.
  </Step>

  <Step title="Edit in Code or Visual mode">
    The template will appear in Design Studio, where you can view and edit it in either **Code** or **Visual** mode using the Editor Preference toggle.
  </Step>
</Steps>

Design Studio uses an editor similar to Parcel.io (which is part of Customer.io). Visual edits (including spacing, padding, and styles) are made via CSS rather than Brew's block-based controls. Images and links from the original Brew template are retained on import.

## Requirements

* A Customer.io account
* An App API key (not a Tracking API key)
* Your datacenter region (US or EU)

<Snippet file="need-help.mdx" />