Firebase messaging/mismatched-credential

Question

I'm trying to send notifications to a specific device with Firebase but am getting the following error:

{"r": {"results":[{"error":{"code":"messaging/mismatched-credential","message":"The credential used to authenticate this SDK does not have permission to send messages to the device corresponding to the provided registration token. Make sure the credential and registration token both belong to the same Firebase project."}}],"canonicalRegistrationTokenCount":0,"failureCount":1,"successCount":0,"multicastId":5165415028752234000}}

I'm not sure what is causing this, I'm using the service account associated with the project and the proper device id.

Any help would be great, thanks!

Answer 1

The issue was with my google-services.json. My app uses two projects and was defaulting to the first project. Adding the second project json file ended up fixing this since it can now send the tokens to the proper project.

Answer 2

This error message can be found in the documentation for FCM.

It means that you've initialized the Admin SDK with a credential for a project that is not the same as the device registration token.

To put it another way: for security reasons, you can't simply send messages to any device token that you come up with. You can only send messages to device tokens via apps in the same project.

Answer 3

I faced the same problem. It took me two days to figure out that I need to enable the Firebase Cloud Messaging API through google cloud platform. Without enabling it, it also yields the error "mismatched-credential". I really wish that the error message could be more specific.