How to get sha256_cert_fingerprints for assetlinks.json for Expo?

Question

Instructions for android universal deep links requires you to upload .well-known/assetlinks.json for verification. Expo deep linking documentation points you to format the file per official android documentation, but the documentation assumes you are using android studio to build your app. https://developer.android.com/training/app-links/verify-site-associations

sha256_cert_fingerprints: The SHA256 fingerprints of your app’s signing certificate. You can use the following command to generate the fingerprint via the Java keytool: keytool -list -v -keystore my-release-key.keystore

The documentation also is unclear about what the value of namespace needs to be.

Mahican

Answer 1

I Just wanted to put this out here for any Expo users, I spent way too much time trying to sort through this when the answer is super simple. Fortunately google provides the entire JSON file for you within the Console play store additionally we don't need to change the namespace as this namespace field is not specific to the app, leave it as android_app

Navigate to: Google Play Store > All Apps > Select the app in question > Setup > App integrity

At the top there is a tab called "App signing"

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Next Scroll to the bottom and you'll see a field that contains all the JSON you need that you can copy into your file:

Mahican

I do not see this in App Integrity. Could it be because I'm working with an unreleased app? Or maybe they moved it in their dashboard? – Beckett

thanks! for informing this piece information! – Cyte

@Beckett hopefully you found it. You now need to click on a tab at the top of App Integrity called "App Signing" that then has the JSON at the bottom of the page. I would assume this is available for all users whether the app is previously released or not, but cannot confirm. – Mahican

Excited you were able to get this working, so many docs and nothing really is super clear. I have found the filled out copy paste assetlinks.json info in my google developer App integrity page. Does an expo EAS internal apk build that is installed directly to my device work with this or do I need to create a new testing release through google play and install from there? I feel like I've tried this but maybe I messed it up and need to try again. Thanks. – Cornwell

It seems the layout was changed and the App Integrity was not under Setup, but as a direct child of Versions, and "App signing" was not in a different tab, but below the "API Play Integrity" section. It can also be accessed under "Settings" (or Setup, I'm not using the Play Store in English) in the left panel. – Lichfield