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

# Customer.io

> Search Customer.io people, inspect campaigns, segments, and metrics, and send transactional email

## At a glance

* **Availability**: Experimental ([how to enable](/cloud/integrations)).
* **Auth**: API key.
* **Connection**: The key from `CUSTOMERIO_APP_API_KEY` is sent as the `Bearer` prefixed `Authorization` header.
* **Docs**: [https://docs.customer.io/integrations/api/app/](https://docs.customer.io/integrations/api/app/)

## Credentials

Set these per environment. See [Connect an integration](/cloud/integrations).

| Variable                 | Required | Description                                                                                                        |
| ------------------------ | -------- | ------------------------------------------------------------------------------------------------------------------ |
| `CUSTOMERIO_APP_API_KEY` | Yes      | Customer.io App API Key (Bearer token for api.customer.io) [Docs](https://docs.customer.io/integrations/api/app/). |

## Setup

1. **Create a Customer.io account**: Sign up at [https://customer.io/](https://customer.io/) - the free trial includes a full workspace suitable for development and testing.
2. **Create an App API key**: In Customer.io go to Settings > Account Settings > API Credentials, open the App API Keys tab, and create a key. Scope it to the workspace and permissions your agents need (read access plus transactional send if you use the email tool).
3. **Set the environment variable**: Copy the key into CUSTOMERIO\_APP\_API\_KEY. It is sent as a Bearer token in the Authorization header on every request.
4. **Optional: set up a transactional message**: To send templated transactional email, create a Transactional message in Customer.io and use its ID or trigger name as transactional\_message\_id.

* Customer.io has US and EU regions. This connector targets the US host api.customer.io; if your workspace is in the EU data center, replace the host with api-eu.customer.io in the tool URLs.
* These tools use the App API (Bearer App API key). The separate Track API (track.customer.io) for identifying people and sending events uses HTTP Basic auth with a site ID and Track API key and is not covered by this connector.
* App API rate limits: most endpoints allow 10 requests per second; transactional sends allow 100 requests per second.

Provider API reference: [https://docs.customer.io/integrations/api/app/](https://docs.customer.io/integrations/api/app/)

## Tools

| Tool                        | Access | Description                                                                                                                 |
| --------------------------- | ------ | --------------------------------------------------------------------------------------------------------------------------- |
| Search Customers            | Read   | Search Customer.io people by attribute or segment filter conditions                                                         |
| List Campaigns              | Read   | List campaigns in the Customer.io workspace with their state and goals                                                      |
| Get Campaign Metrics        | Read   | Get delivery and conversion metrics for a Customer.io campaign over a time period                                           |
| Get Person Attributes       | Read   | Get a person's full attribute profile by ID, email, or cio\_id (Search Customers returns only identifiers)                  |
| List Transactional Messages | Read   | List the workspace's transactional message templates so agents can find a valid transactional\_message\_id before sending   |
| Trigger Broadcast           | Write  | Trigger an API-triggered broadcast campaign, optionally overriding the recipients and passing liquid data into the messages |
| List Segments               | Read   | List segments in the Customer.io workspace so agents can target or filter people                                            |
| Send Transactional Email    | Write  | Send a transactional email to a recipient, using a transactional message template or inline subject and body                |

## Example prompts

* List my Customer.io campaigns and summarize the recent metrics for the active ones.
* Search Customer.io for a person by email and show their identifiers.
* Send a transactional email via Customer.io to the recipient I specify.