ios: Universal links not working on iOS 10

Question

I'm trying to integrate universal links in my iOS app. So whenever someone taps on <myapp>.herokuapp.com/content gets redirected directly to app. I followed this guide for setup. I did the following setup but cannot get it working. I also checked other threads on stackoverflow but none of them solved the issue.

• Added Associated Domains in Capabilities Tab on my app's target. Added two domains: activitycontinuation:<myapp>.herokuapp.com and applinks:<myapp>.herokuapp.com.
• In Build Phases > Copy Bundle Resources added the file .entitlements.
• Got teamId from https://developer.apple.com/account/#/membership

• On my website added a route for apple-app-site-association at https://<myapp>.herokuapp.com/apple-app-site-association which returns the following json:

  {
      "applinks": {
          "apps": [],
          "details": [
              {
                  "appID": "<teamId>.<bundleId>.dev",
                  "paths": [ "*" ]
              },
              {
                  "appID": "<teamId>.<bundleId>",
                  "paths": [ "*" ]
              }
          ]
      },
      "activitycontinuation": {
          "apps": [
              "<teamId>.<bundleId>.dev",
              "<teamId>.<bundleId>"
          ]
      }
  }
  

• Installed app from Xcode to iPhone 6s Plus (physical device) with bundle id <bundleId>.dev and copied link https://<myapp>.herokuapp.com/content to Notes but it opens in Safari.

Answer 1

Fixed the issue. The problem was that I was testing with Debug configuration. When I tried with Release build everything is now working fine.

Answer 2

There are quite a lot of issues that could be preventing your Universal Links from working here.

Here are some things to double-check:

• Is the AASA file properly named, and properly signed?
• Are you testing with a physical device? (some say Universal Links now work consistently in the simulator with iOS 10, but I'd still use a physical device)
• Are your device and provisioning certificates all error-free?
• Could the AASA file have failed to update when the app was first installed/launched due to an issue with network connectivity (I find that the AASA will fail to download if Charles Proxy is capturing traffic, for example)
• When testing, are you first pasting the link into Notes and then long-pressing on it? Are you seeing the "Open in App" menu option? If so, Universal Linking is working properly and has just been disabled on the device.

I would also recommend running through Alex Austen's super blog post on this topic, as doing so may help you spot the problem (here: https://blog.branch.io/how-to-setup-universal-links-to-deep-link-on-apple-ios-9/).

Branch has a number of tools/resources for identifying Universal Linking issues. They are specifically intended for use with Branch links, but you may still find them helpful:

• AASA Validator: https://branch.io/resources/aasa-validator/
• Universal Link Validator: https://dev.branch.io/getting-started/universal-linking-validator/guide/
• Universal Linking Troubleshooting Guide: https://support.branch.io/support/solutions/articles/6000153326-ios-universal-links-troubleshooting-guide