return strings.Contains(addr, ".googleapis.com/") || strings.Contains(addr, ".googleapis.com:443/")
}

func mcpTransport(ctx context.Context, tr http.RoundTripper) (http.RoundTripper, error) {
	creds, err := google.FindDefaultCredentials(ctx, "https://www.googleapis.com/auth/cloud-platform")
	if err != nil {
		return nil, fmt.Errorf("finding default GCP credentials: %w", err)
	}
	return &oauth2.Transport{
		Base:   tr,
		Source: creds.TokenSource,