Metrics.ts

Metrics.ts overview

OpenTelemetry support for Effect metrics.

This module exposes Effect metrics as an OpenTelemetry MetricProducer. makeProducer creates the producer, registerProducer attaches it to one or more SDK MetricReaders, and layer manages that setup in a scoped layer. The TemporalityPreference type lets callers choose cumulative or delta metric values.

Since v4.0.0

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Exports Grouped by Category

• constructors
  • makeProducer
  • registerProducer
• layers
  • layer
• models
  • TemporalityPreference (type alias)

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constructors

makeProducer

Creates an OpenTelemetry metric producer from Effect metrics.

When to use

Use when you need a MetricProducer for manually wiring Effect metrics into OpenTelemetry instead of using the scoped layer helper.

Details

Requires the current OpenTelemetry Resource, captures the current Effect context, and uses cumulative temporality by default. Pass "delta" for interval-based values.

See

• registerProducer for attaching a producer to metric readers
• layer for creating and registering a producer in a scoped layer

Signature

declare const makeProducer: (temporality?: TemporalityPreference) => Effect.Effect<MetricProducer, never, Resource>

Source

Since v4.0.0

registerProducer

Registers a metric producer with one or more metric readers.

Signature

declare const registerProducer: (
  self: MetricProducer,
  metricReader: LazyArg<MetricReader | Arr.NonEmptyReadonlyArray<MetricReader>>,
  options?: { readonly shutdownTimeout?: Duration.Input | undefined }
) => Effect.Effect<Array<any>, never, Scope.Scope>

Source

Since v4.0.0

layers

layer

Creates a Layer that registers a metric producer with metric readers.

Example (Creating a metrics layer with temporality)

import { Metrics } from "@effect/opentelemetry"
import { PeriodicExportingMetricReader } from "@opentelemetry/sdk-metrics"
import { OTLPMetricExporter } from "@opentelemetry/exporter-metrics-otlp-http"

const metricExporter = new OTLPMetricExporter({ url: "<your-otel-url>" })

// Use delta temporality for backends like Datadog or Dynatrace
const metricsLayer = Metrics.layer(
  () =>
    new PeriodicExportingMetricReader({
      exporter: metricExporter,
      exportIntervalMillis: 10000
    }),
  { temporality: "delta" }
)

// Use cumulative temporality for backends like Prometheus (default)
const cumulativeLayer = Metrics.layer(() => new PeriodicExportingMetricReader({ exporter: metricExporter }), {
  temporality: "cumulative"
})

Signature

declare const layer: (
  evaluate: LazyArg<MetricReader | Arr.NonEmptyReadonlyArray<MetricReader>>,
  options?: {
    readonly shutdownTimeout?: Duration.Input | undefined
    readonly temporality?: TemporalityPreference | undefined
  }
) => Layer.Layer<never, never, Resource>

Source

Since v4.0.0

models

TemporalityPreference (type alias)

Determines how metric values relate to the time interval over which they are aggregated.

Details

cumulative reports total since a fixed start time. Each data point depends on all previous measurements. This is the default behavior. delta reports changes since the last export. Each interval is independent with no dependency on previous measurements.

Signature

type TemporalityPreference = "cumulative" | "delta"

Source

Since v4.0.0