What causes "failed to get materialized view: %w" in googleapis/mcp-toolbox?

Unwrap with status.FromError and handle codes.NotFound by listing available views first

failed to get materialized view: %w

Error message

failed to get materialized view: %w

What it means

GetMaterializedView wraps errors from InstanceAdmin.MaterializedViewInfo, which fetches details of one materialized view. Failures occur when the view or instance does not exist, permissions are missing, or a transient RPC failure happens. The wrapped error retains the original cause for errors.Is/As checks.

Source

Thrown at internal/sources/bigtable/admin_wrappers.go:240

	err := s.InstanceAdmin.UpdateLogicalView(ctx, instanceId, conf)
	if err != nil {
		return nil, fmt.Errorf("failed to update logical view: %w", err)
	}
	return map[string]string{"status": "logical view updated successfully"}, nil
}

func (s *Source) DeleteLogicalView(ctx context.Context, instanceId, logicalViewId string) (any, error) {
	err := s.InstanceAdmin.DeleteLogicalView(ctx, instanceId, logicalViewId)
	if err != nil {
		return nil, fmt.Errorf("failed to delete logical view: %w", err)
	}
	return map[string]string{"status": "logical view deleted successfully"}, nil
}

func (s *Source) GetMaterializedView(ctx context.Context, instanceId, materializedViewId string) (any, error) {
	view, err := s.InstanceAdmin.MaterializedViewInfo(ctx, instanceId, materializedViewId)
	if err != nil {
		return nil, fmt.Errorf("failed to get materialized view: %w", err)
	}
	return view, nil
}

func (s *Source) CreateMaterializedView(ctx context.Context, instanceId, materializedViewId, query string) (any, error) {
	conf := &bigtable.MaterializedViewInfo{
		MaterializedViewID: materializedViewId,
		Query:              query,
	}
	err := s.InstanceAdmin.CreateMaterializedView(ctx, instanceId, conf)
	if err != nil {
		return nil, fmt.Errorf("failed to create materialized view: %w", err)
	}
	return map[string]string{"status": "materialized view created successfully"}, nil
}

func (s *Source) UpdateMaterializedView(ctx context.Context, instanceId, materializedViewId, query string) (any, error) {
	conf := bigtable.MaterializedViewInfo{ // MUST be value per bigtable SDK

View on GitHub (pinned to 8cc6e09de2)

Solutions

Unwrap with status.FromError and handle codes.NotFound by listing available views first
Verify instanceId/project configuration and that the ID is a materialized view (not a logical view)
Grant roles/bigtable.viewer or roles/bigtable.admin to the caller's service account
Retry on transient gRPC codes (Unavailable, DeadlineExceeded)

Example fix

// before: raw NotFound bubbles to the LLM
view, err := s.InstanceAdmin.MaterializedViewInfo(ctx, instanceId, id)
if err != nil { return nil, fmt.Errorf("failed to get materialized view: %w", err) }
// after: friendlier NotFound handling
view, err := s.InstanceAdmin.MaterializedViewInfo(ctx, instanceId, id)
if err != nil {
    if st, ok := status.FromError(err); ok && st.Code() == codes.NotFound {
        return nil, fmt.Errorf("materialized view %q not found in instance %q", id, instanceId)
    }
    return nil, fmt.Errorf("failed to get materialized view: %w", err)
}

Defensive patterns

Strategy: type-guard

Validate before calling

views, err := src.ListMaterializedViews(ctx, instanceId)
if err != nil { return err }
if !containsMaterializedViewID(views, viewId) {
    return fmt.Errorf("materialized view %q not found in %s", viewId, instanceId)
}

Type guard

func isNotFound(err error) bool {
    st, ok := status.FromError(errors.Unwrap(err))
    return ok && st.Code() == codes.NotFound
}

Try / catch

view, err := src.GetMaterializedView(ctx, instanceId, viewId)
if err != nil {
    if isNotFound(err) {
        return nil, fmt.Errorf("materialized view %q not found", viewId)
    }
    return err
}

Prevention

List materialized views first when the ID may be stale
Don't confuse logical-view IDs with materialized-view IDs
Grant roles/bigtable.viewer at minimum for read operations
Check project/instance configuration if NotFound errors appear unexpectedly

When it happens

Trigger: Calling GetMaterializedView (bigtable_get_materialized_view tool) when: materializedViewId does not exist under instanceId, the instanceId is wrong, the caller lacks bigtable read permissions, or the admin RPC times out.

Common situations: Fetching a view after it was dropped by another process; confusing logical-view IDs with materialized-view IDs; service account missing the Bigtable Viewer/Admin role; project misconfiguration in the source config.

Related errors

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/f3b31089a022c405. Report an issue: GitHub.