weaviate/weaviate · error

not a bool, but %T

Error message

not a bool, but %T

What it means

Type-assertion failure in boolVal: the incoming property value could not be asserted to bool, so the actual Go type is reported. Fires when a boolean property receives a string, number, or null in the object payload.

Source

Thrown at usecases/objects/validation/properties_validation.go:406

		return crefs, nil
	default:
		return nil, fmt.Errorf("invalid ref type. Needs to be []map, got %T", pv)
	}
}

func stringVal(val interface{}) (string, error) {
	typed, ok := val.(string)
	if !ok {
		return "", fmt.Errorf("not a string, but %T", val)
	}

	return typed, nil
}

func boolVal(val interface{}) (bool, error) {
	typed, ok := val.(bool)
	if !ok {
		return false, fmt.Errorf("not a bool, but %T", val)
	}

	return typed, nil
}

func dateVal(val interface{}) (time.Time, error) {
	if dateStr, ok := val.(string); ok {
		if date, err := time.Parse(time.RFC3339, dateStr); err == nil {
			return date, nil
		}
	}

	errorInvalidDate := "requires a string with a RFC3339 formatted date, but the given value is '%v'"
	return time.Time{}, fmt.Errorf(errorInvalidDate, val)
}

func uuidVal(val interface{}) (uuid.UUID, error) {
	if uuidStr, ok := val.(string); ok {

View on GitHub (pinned to 75aa4b6d11)

Solutions

1. Use bare JSON true/false.
2. Convert truthy strings/numbers to booleans client-side.
3. Fix the schema dataType if the source data isn't boolean.

When it happens

Trigger: Thrown at usecases/objects/validation/properties_validation.go:406 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of weaviate/weaviate@75aa4b6d11 (2026-09-04). Data as JSON: /api/errors/74134081bbaea70f. Report an issue: GitHub.