Troubleshoot your ADC setup

This page describes some common problems you might encounter when using Application Default Credentials (ADC).

For information about how ADC works, including where credentials are found, see How Application Default Credentials works.

User credentials not working

If your API request returns an error message about user credentials not being supported by this API, the API not being enabled in the project, or no quota project being set, review the following information.

There are two kinds of Google Cloud APIs:

  • Resource-based APIs, which use the project associated with the resources being accessed for billing and quota.

  • Client-based APIs, which use the project associated with the client accessing the resources for billing and quota.

When you provide user credentials to authenticate to a client-based API, you must specify the project to use for billing and quota. This project is called the quota project.

There are a number of ways to specify a quota project, including the following options:

  • Update ADC to use a different project as the quota project:

    gcloud auth application-default set-quota-project YOUR_PROJECT
  • If you are calling the REST or RPC API directly, use the x-goog-user-project HTTP header to specify a quota project in each request. For details, see Set the quota project with a REST request.

You must have the IAM permission for a project to be able to designate it as your billing project. The permission is included in the Service Usage Consumer IAM role. If you don't have the permission for any project, contact your security administrator or a project owner who can give you the Service Usage Consumer role in the project.

For more information about quota projects, see Quota project overview. For information about additional ways to set the quota project, see Set the quota project.

Incorrect credentials

If your credentials don't seem to be providing the access you expect, or aren't found, check the following:

  • If you are using the gcloud CLI to access Google Cloud in a local environment, make sure you understand which credentials you are using. When you use the gcloud CLI, you are using the credentials you provided to the gcloud CLI by using the gcloud auth login command. You are not using the credentials you provided to ADC. For more information about these two sets of credentials, see gcloud CLI authentication configuration and ADC configuration .

  • Make sure that the GOOGLE_APPLICATION_CREDENTIALS environment variable is set only if you are using a service account key or other JSON file for ADC. The credentials pointed to by the environment variable take precedence over other credentials, including for Workload Identity.

  • Confirm that the principal making the request has the required IAM roles. If you are using user credentials, then the roles must be granted to the email address associated with the user account. If you are using a service account, then that service account must have the required roles.

  • If you provide an API key with the API request, the API key takes precedence over ADC in any location. If you have set the GOOGLE_APPLICATION_CREDENTIALS environment variable and you are using an API key, the API might return a warning telling you that the credentials you provided to ADC are being ignored. To stop the warning, unset the GOOGLE_APPLICATION_CREDENTIALS environment variable.

Unrecognized credential type

If your API request returns an error that includes "Error creating credential from JSON. Unrecognized credential type", make sure you are using a valid credential. Client ID files are not supported to provide credentials for ADC.