The Atlas supports federated login with external Identity Providers via OIDC (https://www.mongodb.com/docs/atlas/workforce-oidc/) for authenticating human users in tools like mongosh or Mongo Compass.

Unfortunately the OIDC login doesn't work with the GCP IdP: OAuth2 clients in Google IdP always have a client secret (even clients considered as "public"). There is no way to specify the client secret in Atlas UI in the Workload Federation configuration and this leads to "invalidrequest (clientsecret is missing.)" error returned from the IdP as it always expects a client secret to be present.

The support of an optional client secret in the Atlas Workload Federation configuration will enable the integration with the GCP IdP.