403 Error: unregistered callers

Hi everyone,

I created an API that can access specific sheets in Google Drive and read some data from it. I have configured the API key, OAuth 2.0 Client ID, and consent screen in GoogleConsole. I have enabled Google Drive API and Google Sheets API as well.

This is the feature that I don’t use often so once I implemented it a few weeks ago I was able to read this data and perform this ‘read’ call successfully, and today I got the following error for the very same call:

{ “code” : 403, “errors” : [ { “domain” : “global”, “message” : “Method doesn’t allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.”, “reason” : “forbidden” } ], “message” : “Method doesn’t allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.”, “status” : “PERMISSION_DENIED” }

I checked GoogleConsole for any quotas that might be exceeded, key that might be expired or services that might be disabled and I saw that configuration is unchanged so I don’t know what else could provoke this issue. Also no changes were made on the document itself and I use the same google account to try this ‘read’ call.

I’d appreciate any hint or advice on where to look for root of this issue

My credentials suddenly quit working today. Everything appears up to date in the cloud console. I wonder if it is related.

Have you noticed anything specific that might help in troubleshooting? I’m still trying to figure out what might have caused the sudden change in access.