Example GET request to manage topic subscriptions from the server side using Firebase Cloud Messaging

Question

I found at https://developers.google.com/instance-id/reference/server#get_information_about_app_instances the following example GET request:

https://iid.googleapis.com/iid/info/nKctODamlM4:CKrh_PC8kIb7O...clJONHoA?details=trueAuthorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA

The key in that example is: AIzaSyZ-1u...0GBYzPu7Udno5aA. Where can I find my key, the one that I should use in my GET request? I am trying to find it at https://console.developers.google.com/apis/credentials, and this is what I see:

I tried using all of the four keys that you see in the image above, and I always receive this message from the browser:

{"error":"MissingAuthorization"}

Does this error refer to the key being wrong, or to something else? Am I looking in the right place for the key? Thank you.

EDIT 1: I was looking at the question at How to check how many topics has been subscribed?, and I also tried using the keys that I found in my Firebase Console, under the "Cloud Messaing" tab. This is what I see:

I tried the GET request using those keys in the image above as well and I still see the same error: {"error":"MissingAuthorization"}.

EDIT 2: I am using this from the command line:

C:\curl>curl -k https://iid.googleapis.com/iid/info/nKctODamlM4:CKrh_PC8kIb7O...clJONHoA?details=trueAuthorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA
{"error":"MissingAuthorization"}
C:\curl>

Notice how I simply copied/pasted what I found at https://developers.google.com/instance-id/reference/server#get_information_about_app_instances under the "Example GET request" heading. I am not even attempting to use my own keys and I see the same error: {"error":"MissingAuthorization"}. Does it mean the problem is with the key I am using? Is not it the one I see in the Firebase Console?

Answer 1

Based on the instructions at https://developers.google.com/instance-id/reference/server, under the heading "Get information about app instances", it shows that it is necessary to provide the Authorization: key=YOUR_API_KEY, which is set in the header. See at https://android.jlelse.eu/firebase-push-notification-using-curl-command-devoid-backend-e63795d282c4 an example of how to provide a parameter in the header.

Concerning the Authorization: key=YOUR_API_KEY that has to be used, it is the key that appears in the "EDIT 1" section of this question. I used the Server key, not the Legacy server key, and it worked for me.

https://developers.google.com/instance-id/reference/server shows this end point: https://iid.googleapis.com/iid/info/IID_TOKEN. But IID_TOKEN must be replaced with the instance ID token which corresponds to the instance of the app that was installed on a device. In my case, I found it by printing the instance ID or token of the device, using the following code in the first activity of my Android app:

Log.d("The token of device: ", FirebaseInstanceId.getInstance().getToken());

In the log of the Android monitor, I found the IID_TOKEN that I needed:

D/The token of device:: f35EFw4bsef:QWE34bFm56ZuQLWYSDDgPlkf4a88Lu6Gp4DoXVDJ5dRIlsdDncq0UdNnlDi7wxbbut6YX7Z1kwgyS3bzk_Zrl-1doHCf9XFdOXTThNzo4sDFEWqQjHKfNa3uH2Js4Flbf_CnRkD2Mftr

Finally, I used cURL from the command prompt, and you can see how I obtained results correctly:

C:\curl>curl -X GET -k --header "Authorization: key=AAAAJ5XteYp:DKE32aIdFalyFXku6A-eR_wHL6ZBUFxfyPtcrm3wwF2l-nPEv_vAeYqo3NJzaIKKcSSow6gqoAwf3cBEm8QWYbF6w-asW0SX0RmHZftQglwmo_ziwrk8wFcGp1_DOQ1PLFFgP4BFWXAD" "https://iid.googleapis.com/iid/info/f35EFw4bsef:QWE34bFm56ZuQLWYSDDgPlkf4a88Lu6Gp4DoXVDJ5dRIlsdDncq0UdNnlDi7wxbbut6YX7Z1kwgyS3bzk_Zrl-1doHCf9XFdOXTThNzo4sDFEWqQjHKfNa3uH2Js4Flbf_CnRkD2Mftr
{"applicationVersion":"22","attestStatus":"NOT_ROOTED","application":"com.[myapp]","scope":"*","authorizedEntity":"232255245625","appSigner":"3d34g3fs3443292d825f21da4fdd5b34a56f2a3h","platform":"ANDROID"}
C:\curl>

Note: In the code above I have changed the values of things such as tokens and keys for privacy purposes, but you need to use your values and everything should work.