> This page is part of the [Customer.io documentation](https://docs.customer.io). For the complete index, see [llms.txt](https://docs.customer.io/llms.txt).
> Last updated: September 1, 2026
> To take actions in Customer.io from an agent, use the [Customer.io CLI](https://docs.customer.io/ai/cli/get-started.md) or the [MCP server](https://docs.customer.io/ai/mcp/get-started.md).

# Set up in-app messages

This page is part of a setup flow for the SDK. Before you continue, make sure you've implemented previous features—i.e. you can't receive in-app notifications before you identify people!

## How it works

An in-app message is a message that people see within the app. People won’t see your in-app messages until they open your app. If you set an *expiry* period for your message, and that time elapses before someone opens your app, they won’t see your message.

You can also set *page rules* to display your in-app messages when people visit specific pages in your app. However, to take advantage of page rules, you need to use [screen tracking](/integrations/sdk/expo/track-events/#auto-screenview) features. Screen tracking tells us the names of your pages and which page a person is on, so we can display in-app messages on the correct pages in your app.

## Set up in-app messaging

Before you can take advantage of in-app messaging, you need to set up your workspace to receive in-app messages. You’ll find your in-app settings under [**Settings** > **Workspace Settings** > **In App Settings**](https://fly.customer.io/env/last/settings).

You also need to set `enableInApp` to `true` in your configuration options.

```
import { CustomerIO, CustomerioConfig, CustomerIOEnv, Region } from 'customerio-reactnative';

const data = new CustomerioConfig()
data.logLevel = CioLogLevel.debug
data.autoTrackDeviceAttributes = true

// In-app messages are optional and disabled by default
// To enable in-app messages, set enableInApp to true
data.enableInApp = true

CustomerIO.initialize(env, data)
```

## Page rules

You can set page rules when you create an in-app message. A page rule determines the page that your audience must visit in your app to see your message. However, before you can take advantage of page rules, you need to:

1.  Track screens in your app. See the [Track Events](/integrations/sdk/expo/track-events/#manual-screenview) page for help sending `screen` events.
2.  Provide page names to whomever sets up in-app messages in fly.customer.io. If we don’t recognize the page that you set for a page rule, your audience will never see your message.

 ![Set up page rules to limit in app messages by page](https://docs.customer.io/images/in-app-page-rule.png)

Keep in mind: page rules are case sensitive. If you’re targeting your mobile app, make sure your page rules match the casing of the `name` in your `screen` events. If you’re targeting your website, your page rules should always be lowercase.

 ![The first page rule is Web contains /dashboard. The second page rule is iOS contains Dashboard.](https://docs.customer.io/images/page-rule-case-sensitive.png)

[GitHub project](https://github.com/customerio/customerio-expo-plugin "View the Expo SDK on GitHub")

Version

3.9.1 (Current)1.x (1.0.0-beta.17, prerelease)

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