expo-app-clip — Claude Code skill: add iOS App Clip to Expo

---
name: expo-app-clip
description: Add an iOS App Clip target to an Expo app. Use when the user mentions App Clip, AASA, apple-app-site-association, appclips, smart app banner, or wants to ship a lightweight iOS Clip invoked from a URL alongside their parent app.
---

# Add an App Clip to an Expo App

> **Requirements.** Adding the App Clip target is open source. Shipping one requires an Apple Developer Program membership and App Store review, and the AASA file must be served over HTTPS on your domain (any HTTPS host works; EAS Hosting is one option). Building via EAS Build or `bunx testflight` uses your EAS plan's build minutes. See https://expo.dev/pricing and https://developer.apple.com/app-clips/.

Adds an iOS App Clip target to an Expo project. The Clip lives in `targets/clip/`, ships alongside the parent app, and is invoked from a URL on the app's domain via an Apple App Site Association (AASA) file.

The parent app's bundle ID becomes `com.<username>.<app-name>` and the Clip's is automatically derived as `<parent>.clip` (e.g. `com.bacon.may20.clip`).

## 1. Set `bundleIdentifier` and `appleTeamId`

`bun create target` warns if these are missing. Add to `app.json`:

```json
{
  "expo": {
    "ios": {
      "bundleIdentifier": "com.<username>.<app-name>",
      "appleTeamId": "XX57RJ5UTD"
    }
  }
}
```

## 2. Add the App Clip target

```sh
bun create target clip
```

This installs [`@bacons/apple-targets`](https://github.com/EvanBacon/expo-apple-targets), adds it to the `plugins` array in `app.json`, and writes:

- `targets/clip/expo-target.config.js` — the target's config plugin
- `targets/clip/Info.plist` — Clip Info.plist
- `targets/clip/AppDelegate.swift`, `Assets.xcassets`, etc.

Pick a good icon or reuse the existing one defined in the app — check it with `bunx expo config` under the `icon` or `ios.icon` key.

## 3. Wire up associated domains

The parent app and the Clip each need the Associated Domains entitlement pointing at the domain that hosts the AASA file.

In `app.json`, add both `applinks:` (parent) and `appclips:` (Clip invocation) entries:

```json
{
  "expo": {
    "ios": {
      "associatedDomains": [
        "applinks:may20.expo.app",
        "appclips:may20.expo.app"
      ]
    }
  }
}
```

In `targets/clip/expo-target.config.js`, declare the Clip's entitlement:

```js
/** @type {import('@bacons/apple-targets/app.plugin').ConfigFunction} */
module.exports = (config) => ({
  type: "clip",
  icon: "https://github.com/expo.png",
  entitlements: {
    "com.apple.developer.associated-domains": ["appclips:may20.expo.app"],
  },
});
```

> If you skip this, `expo prebuild` will print: `Apple App Clip may require the associated domains entitlement but none were found`.

## 4. Register bundle IDs and create the App Store entry

```sh
bunx setup-safari
```

This logs in to the Apple Developer account, registers `com.bacon.may20`, creates the App Store Connect entry, and prints:

- A starter `apple-app-site-association` JSON
- A `<meta name="apple-itunes-app">` tag with the iTunes app id
- Team ID, iTunes ID, and Bundle ID

## 5. Host the AASA file

App Clips are invoked when iOS fetches `https://<your-domain>/.well-known/apple-app-site-association` and finds a matching `appclips` entry.

```sh
mkdir -p public/.well-known
touch public/.well-known/apple-app-site-association
```

Paste the JSON `setup-safari` printed, but **add an `appclips` block** for the Clip's full app ID (`<TeamID>.<ClipBundleID>`). The output of `setup-safari` only covers the parent app:

```json
{
  "applinks": {
    "details": [
      {
        "appIDs": ["XX57RJ5UTD.com.bacon.may20"],
        "components": [{ "/": "*", "comment": "Matches all routes" }]
      }
    ]
  },
  "appclips": {
    "apps": ["XX57RJ5UTD.com.bacon.may20.clip"]
  },
  "activitycontinuation": {
    "apps": ["XX57RJ5UTD.com.bacon.may20"]
  },
  "webcredentials": {
    "apps": ["XX57RJ5UTD.com.bacon.may20"]
  }
}
```

Notes:

- The file has **no extension** and **no `Content-Type` requirements** beyond being served as-is. Expo Router static export serves files in `public/` verbatim.
- The `appclips` block is what lets a URL on the domain launch the Clip.
- `webcredentials` is used for sharing credentials between the website, parent app, and the App Clip.
- `activitycontinuation` is optional and used for sharing the link between mobile and desktop. Must be used with `Head` from expo-router — see https://docs.expo.dev/router/advanced/apple-handoff/
- Notation and route-disabling details: https://sosumi.ai/documentation/xcode/supporting-associated-domains

## 6. Add the Smart App Banner meta tag

Create `src/app/+html.tsx` (Expo Router's HTML shell) and add the tag from `setup-safari`. Create the versioned template if it doesn't exist:

```sh
bunx expo customize src/app/+html.tsx
```

Add the meta tag to the `<head>`:

```tsx
import { ScrollViewStyleReset } from "expo-router/html";

export default function Root({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <head>
        <meta charSet="utf-8" />
        <meta httpEquiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <meta name="apple-itunes-app" content="app-id=6771566491" />
        <ScrollViewStyleReset />
      </head>
      <body>{children}</body>
    </html>
  );
}
```

To make the website show the App Clip card instead of the install card, use:

```html
<meta
  name="apple-itunes-app"
  content="app-id=6771566491, app-clip-bundle-id=com.bacon.may20.clip, app-clip-display=card"
/>
```

## 7. Deploy the website

The AASA file must be live before iOS will trust the association. Use [EAS Hosting](https://docs.expo.dev/eas/hosting/):

```sh
bunx expo export -p web
eas deploy --prod
```

This publishes the site (including `/.well-known/apple-app-site-association`) at `https://<slug>.expo.app`. Verify:

```sh
curl https://may20.expo.app/.well-known/apple-app-site-association
```

## 8. Mirror permissions

Inspect the parent app's permissions after prebuild:

```sh
npx expo config --type introspect
```

Look at the `infoPlist` object — mirror the permission keys in the App Clip's `Info.plist` so matching APIs can be used from the Clip.

Set `deploymentTarget: "17.6"` in the Clip's target config — App Clips have a higher minimum size limit in iOS 17.6.

If the app uses push notifications or location services, add to the App Clip's `Info.plist` to request the necessary permissions:

```xml
<key>NSAppClip</key>
<dict>
  <key>NSAppClipRequestEphemeralUserNotification</key>
  <false/>
  <key>NSAppClipRequestLocationConfirmation</key>
  <true/>
</dict>
```

## 9. Build and submit to TestFlight

```sh
bunx testflight
```

This will:

1. Generate an `eas.json` if missing.
2. Set up credentials for **both** targets (parent + Clip). Each gets its own provisioning profile but can share a single Distribution Certificate.
3. Sync capabilities — note `Enabled: Associated Domains` for the Clip target.
4. Build, upload, and schedule a TestFlight submission.

## 10. Configure App Clip metadata

Pull existing App Store metadata to local:

```sh
eas metadata:pull
```

Add `apple.appClip` to `store.config.json`. Up to 3 invocation URLs can launch the Clip from a web page:

```json
{
  "configVersion": 0,
  "apple": {
    "appClip": {
      "defaultExperience": {
        "action": "PLAY",
        "releaseWithAppStoreVersion": true,
        "reviewDetail": {
          "invocationUrls": ["https://may20.expo.app/", null, null]
        },
        "info": {
          "en-US": {
            "subtitle": "Instantly native with Expo",
            "headerImage": "store/apple/app-clip/en-US/asc-app-clip.png"
          }
        }
      }
    }
  }
}
```

The `headerImage` must be a 1800x1200 PNG with no opacity.

Push back to the store:

```sh
eas metadata:push
```

Apple's recommended App Clip metadata guidelines: https://sosumi.ai/documentation/appclip/configuring-the-launch-experience-of-your-app-clip

## What you get

- Parent app target: `com.bacon.may20`
- App Clip target: `com.bacon.may20.clip`, lives in `targets/clip/`
- AASA hosted at `https://may20.expo.app/.well-known/apple-app-site-association`
- Smart App Banner meta tag on every web route
- Every route linked to its native counterpart
- TestFlight build of the parent app with the Clip embedded

Once Apple invokes the Clip from a URL on the domain, iOS opens `targets/clip/`'s entry point which loads the React Native app.

## Native detection (optional)

To let JS detect when it's running inside an App Clip and present an install prompt for the full app, create a local Expo module (`bunx create-expo-module --local`) that exposes `navigator.appClip.prompt()`.

See [./references/native-module.md](./references/native-module.md) for the Swift module, TypeScript interface, and usage.

## References

- ./references/native-module.md — Local Expo module to detect App Clip context and present the SKOverlay install prompt

## Submitting Feedback
If you encounter errors, misleading or outdated information in this skill, report it so Expo can improve:
```bash
npx --yes @expo/agent-cli@latest feedback --category skills --subject "expo-app-clip" "<actionable feedback>"
```
Only submit when you have something specific and actionable to report. Include as much relevant context as possible.
If an agent repeatedly fails at an Expo task or the user has to step in, submit a brief report of the task, expected result, and what went wrong using `--category evals` and the relevant Expo package or command as `--subject`.