Send useful events.

Complete example

await log.error({
  message: "Payment failed",
  eventName: "payment.charge.failed",
  attributes: {
    "payment.provider": "stripe",
    "payment.amount": 49.99,
    "payment.currency": "usd",
    "payment.failure_kind": "card_declined",
    "order.id": "order_456",
    "user.id": "user_123",
  },
});

The method (log.error) sets level. projectName, serviceName, and environment come from your logger configuration and are attached automatically.

Core fields

message

Use a short sentence that someone can understand immediately. Keep the wording stable for the same kind of event so it groups cleanly.

message: "Payment failed"

message: "Database connection timed out"
message: "User signed in"
message: "Invoice generation failed"

message: "Something went wrong"
message: "Error"
message: "Failed"

Put variable data (ids, amounts, counts) in attributes, not in the message string.

level

You do not set level directly — you call the matching method and the SDK sets it.

await log.trace({ message: "Cache lookup", eventName: "cache.lookup.completed" });
await log.debug({ message: "Parsed request body" });
await log.info({ message: "User signed in", eventName: "auth.login.succeeded" });
await log.warn({ message: "Retrying upstream call", eventName: "http.client.retry" });
await log.error({ message: "Payment failed", eventName: "payment.charge.failed" });
await log.fatal({ message: "Event loop stalled", eventName: "system.process.crashed" });

log.warning() is accepted as an alias for log.warn().

eventName

A stable, lowercase identifier for the kind of event. OneMinute Logs uses it to group events, drive alerts, and power anomaly detection, so the same workflow should always emit the same name.

Follow the grammar <domain>[.<object>][.<qualifier>].<outcome> using snake_case segments:

auth.login.succeeded
auth.login.failed
payment.charge.failed
order.created
order.fulfillment.failed
queue.message.failed
http.server.request

Do not invent five names for one thing. Pick one and reuse it.

payment.charge.failed

payment.failed
payment.failure
checkout.payment.error
billing.payment.failed
stripe.payment.failed

attributes

A flat map of structured context. Values may be strings, numbers, booleans, null, or arrays of those. Use dotted, lowercase keys that follow OpenTelemetry semantic conventions where one exists.

attributes: {
  "user.id": "user_123",
  "order.id": "order_456",
  "payment.provider": "stripe",
  "payment.amount": 49.99,
  "http.response.status_code": 500,
  "error.type": "CardError",
}

This is the place for anything you want to search, filter, or alert on: identifiers that follow one user, request, order, or workflow, plus failure detail such as error.type or a *.failure_kind qualifier.

Set defaultAttributes in your logger config for keys that should ride along on every event.

timestamp

Defaults to the moment you call the logger. Set it only when the event actually happened earlier — for example when replaying a queue or importing history.

await log.info({
  message: "Webhook received",
  eventName: "webhook.inbound.received",
  timestamp: new Date(webhook.created_at),
});

Accepts a Date, an RFC-3339 string, or a millisecond epoch number.

traceId & spanId

Set these only when they come from a real distributed-tracing context (an active OpenTelemetry span, or an incoming traceparent header). Do not generate random values — OneMinute Logs uses them to link an event to its trace.

await log.error({
  message: "Payment failed",
  eventName: "payment.charge.failed",
  traceId: span.spanContext().traceId,
  spanId: span.spanContext().spanId,
});

Automatically added fields

You never send these — the SDK and the backend fill them in:

Stored event shape

When you read events back with getLogs or getStream, each event is a normalized, camelCase LogEvent:

See Search & Filters for how to query these fields.

Recommended naming

Use lowercase, consistent values everywhere.

eventName: "payment.charge.failed"   // dotted, snake_case segments
"payment.provider": "stripe"          // dotted attribute keys
"user.id": "user_123"

Avoid mixing styles.

eventName: "PaymentFailed"
eventName: "payment-charge-failed"
"userId": "user_123"

Consistency is what makes filters, alerts, and grouping reliable across services.

Start simple

You do not need every field. A message and the right method is a valid event.

await log.error({
  message: "Payment failed",
  eventName: "payment.charge.failed",
});

Add attributes only when they help you search, investigate, or alert.

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