add-app-clip skill

Add an App Clip to an Expo App

When to Use

Use this skill when you need 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.

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.. and the Clip's is automatically derived as .clip (e.g. com.bacon.may20.clip).

1. Set bundleIdentifier and appleTeamId

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

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

2. Add the App Clip target

bun create target clip

This installs @bacons/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:

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

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

/** @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

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 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:///.well-known/apple-app-site-association and finds a matching appclips entry.

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 (.). The output of setup-safari only covers the parent app:

{
  "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:

bunx expo customize src/app/+html.tsx

Add the meta tag to the :

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:

<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:

bunx expo export -p web
eas deploy --prod

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

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

8. Mirror permissions

Inspect the parent app's permissions after prebuild:

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:

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

9. Build and submit to TestFlight

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:

eas metadata:pull

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

{
  "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.