Events

Events capture things that happened — decisions, state transitions, milestones — with structured attributes:

Telemetry::event('autoscale.decision', [
    'workers.current' => 4,
    'workers.desired' => 7,
    'reason' => 'queue_depth',
]);

Emitted inside a span, the event carries the trace and span id — your backend can show it on the trace timeline:

Telemetry::span('autoscale.evaluate', function () {
    // ...
    Telemetry::event('autoscale.decision', ['workers.desired' => 7]);
});

Events buffer with spans and export at terminate as OTLP log records (/v1/logs, severity INFO, body = event name).

Events vs. span events vs. metrics

• Telemetry::event() — standalone record, queryable in your log/trace backend. Use for domain decisions you'll want to look up later.
• $span->addEvent() — a timestamped annotation inside one span. Use for checkpoints during traced work.
• Counter — when you only care how often, not each occurrence.