googleapis/mcp-toolbox · error

incorrect settings: %w

Error message

incorrect settings: %w

What it means

After building the Looker SDK session with client credentials, Initialize performs a smoke-test call to the Looker /user (Me) endpoint. If that login/API call fails, the credentials or base URL settings are wrong and this wrapped error is returned, embedding the SDK's underlying message. It converts a runtime auth failure into a clear startup error.

Source

Thrown at internal/sources/looker/looker.go:137

	var tokenSource oauth2.TokenSource
	tokenSource, _ = initGoogleCloudConnection(ctx)

	s := &Source{
		Config:              r,
		ApiSettings:         &cfg,
		TokenSource:         tokenSource,
		AuthTokenHeaderName: "Authorization",
	}

	if strings.ToLower(r.UseClientOAuth) == "false" {
		if r.ClientId == "" || r.ClientSecret == "" {
			return nil, fmt.Errorf("client_id and client_secret need to be specified")
		}
		s.Client = v4.NewLookerSDK(rtl.NewAuthSession(cfg))
		resp, err := s.Client.Me("", s.ApiSettings)
		if err != nil {
			return nil, fmt.Errorf("incorrect settings: %w", err)
		}
		logger.DebugContext(ctx, fmt.Sprintf("logged in as %s %s", *resp.FirstName, *resp.LastName))
	} else {
		if strings.ToLower(r.UseClientOAuth) != "true" {
			s.AuthTokenHeaderName = r.UseClientOAuth
		}
		logger.DebugContext(ctx, fmt.Sprintf("Using AuthTokenHeaderName: %s", s.AuthTokenHeaderName))
	}

	return s, nil

}

var _ sources.Source = &Source{}

type Source struct {
	Config
	Client              *v4.LookerSDK

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Verify the embedded SDK error in the message and re-generate Looker API3 client_id/client_secret for an active user.
2. Confirm baseUrl points to your actual Looker instance (e.g. https://mycompany.looker.com) and is reachable (curl it).
3. Ensure the Looker user owning the credentials can log in via API and has permission to view their own user record.

Example fix

# before (stale secret)
    client_id: abc123
    client_secret: old-secret
# after
    client_id: abc123
    client_secret: ${LOOKER_CLIENT_SECRET}  # freshly generated in Looker Admin > Users > API3

// before start: confirm Looker API is reachable and credentials work
curl -sS -o /dev/null -w '%{http_code}' https://mycompany.looker.com/api/4.0/login -d "client_id=$LOOKER_CLIENT_ID&client_secret=$LOOKER_CLIENT_SECRET"
// expect 200; non-2xx means the toolbox will fail with 'incorrect settings'

src, err := cfg.Initialize(ctx, tracer)
if err != nil {
    if strings.Contains(err.Error(), "incorrect settings") {
        var sdkErr error
        if errors.As(err, &sdkErr) || true { /* wrapped %w */ }
        fmt.Printf("Looker login failed: %v — check credentials, baseUrl, and network reachability\n", err)
    }
    return err
}

When it happens

Trigger: client_id/client_secret present but invalid/revoked, baseUrl pointing at a non-Looker or wrong-instance URL, network/DNS failure to Looker, or API3 credentials without sufficient permissions — the Me call returns an error.

Common situations: Rotated Looker API3 keys still configured in the toolbox; wrong baseUrl (e.g. missing instance subdomain); firewall/proxy blocking the Looker API; credentials from a disabled Looker user.

Related errors

• error fetching connections: %w
• unable to create bigtable.NewClient: %w
• error creating new sqladmin service: %w
• failed to find default Google Cloud credentials for project
• failed to initialize Firebase Rules client: %w

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/e86307b898237e26. Report an issue: GitHub.