Logs

OtelLogger emits structured log records inside the same SDK.

Basic usage

Otel.instance.logger.info(
  'Loading user',
  attributes: const {
    'user.id': '42',
    'cache.hit': false,
  },
);

Error logging

try {
  await fetchUser();
} catch (error, stackTrace) {
  Otel.instance.logger.error(
    'User load failed',
    exception: error,
    stackTrace: stackTrace,
    attributes: const {'route': '/user'},
  );
}

Severity levels

The core package includes severities such as:

• TRACE
• DEBUG
• INFO
• WARN
• ERROR
• FATAL

Relation to traces

When a log is emitted inside an active span context, trace and span identifiers can be attached automatically through the provider pipeline.

That makes logs and spans easier to correlate downstream.

When to log vs trace

• traces: lifecycle of an operation
• logs: noteworthy events inside or outside an operation
• metrics: aggregate behavior over time

Use all three together rather than forcing one signal type to do every job.