# Attributes



Every log method accepts an optional second argument: an object of structured attributes attached to that single log entry. Use it to record the data that makes a log message useful to search and filter on later.

```js
flare.logger.info('Order placed', {
    orderId: 'ord_8231',
    total: 49.99,
    currency: 'EUR',
    items: 3,
});
```

Attribute values can be strings, numbers, booleans, `null`, arrays, or nested objects:

```js
flare.logger.warning('Validation failed', {
    field: 'email',
    errors: ['required', 'invalid_format'],
    context: { formId: 'signup', step: 2 },
});
```

## How attributes are handled

Attributes are **frozen at the moment you record the log**. The client encodes them immediately, so later changes to the original object don't affect the buffered entry. Pass the values you want captured at call time.

Attributes you set on a log entry apply only to that entry. They are not shared with other logs or with error reports.

## Service-wide identity

Set `serviceName` once through configuration to attach it to every log batch (sent as `service.name`), rather than passing it per-call:

```js
flare.configure({
    enableLogs: true,
    serviceName: 'storefront',
});
```