Metrics

The Producer records OpenTelemetry metrics on the produce path via otel4s. Metrics are off by default (a no-op instrument bundle), so you only pay for what you opt into.

There are two ways to enable them:

1. Bring your own MeterProvider — wire the producer into any OpenTelemetry backend you already run (withMetrics).
2. Export to CloudWatch — a batteries-included module that ships metrics straight to Amazon CloudWatch (buildWithCloudWatch). Unlike the Java-SDK client, this path is cross-platform (JVM/JS/Native): the CloudWatch client is the pure-Scala smithy4s client and the exporter is otel4s-sdk.

The emitted metric names, units, and attributes are identical to the Java-SDK client — see the client metrics reference for the full table. The instrumentation scope is kinesis4cats and the metric-name namespace defaults to kinesis4cats.producer.

Bring your own MeterProvider

Both the KinesisProducer and FS2KinesisProducer builders expose withMetrics, which takes any otel4s MeterProvider. The example below uses MeterProvider.noop as a stand-in — swap in your real provider.

import cats.effect._
import org.http4s.blaze.client.BlazeClientBuilder
import org.typelevel.otel4s.metrics.MeterProvider
import smithy4s.aws._

import kinesis4cats.smithy4s.client.producer.KinesisProducer
import kinesis4cats.models.StreamNameOrArn

BlazeClientBuilder[IO].resource.flatMap(client =>
  KinesisProducer.Builder
    .default[IO](StreamNameOrArn.Name("my-stream"), client, AwsRegion.US_EAST_1)
    .withMetrics(MeterProvider.noop[IO])
    .build
)

Export to CloudWatch

The smithy4s-client-opentelemetry module bundles a CloudWatch-exporting MeterProvider with the producer.

libraryDependencies += "io.github.etspaceman" %% "kinesis4cats-smithy4s-client-opentelemetry" % "0.5.0"

Import the syntax and add withCloudWatchMetrics() to the builder before build. By default it reuses the builder's own http4s client and region:

import cats.effect._
import org.http4s.blaze.client.BlazeClientBuilder
import smithy4s.aws._

import kinesis4cats.smithy4s.client.producer.KinesisProducer
import kinesis4cats.smithy4s.client.producer.opentelemetry.syntax.cloudwatch._
import kinesis4cats.models.StreamNameOrArn

BlazeClientBuilder[IO].resource.flatMap(client =>
  KinesisProducer.Builder
    .default[IO](StreamNameOrArn.Name("my-stream"), client, AwsRegion.US_EAST_1)
    .withCloudWatchMetrics()
    .build
)

The same syntax is available on the FS2KinesisProducer builder:

import cats.effect._
import org.http4s.blaze.client.BlazeClientBuilder
import smithy4s.aws._

import kinesis4cats.smithy4s.client.producer.fs2.FS2KinesisProducer
import kinesis4cats.smithy4s.client.producer.opentelemetry.syntax.cloudwatch._
import kinesis4cats.models.StreamNameOrArn

BlazeClientBuilder[IO].resource.flatMap(client =>
  FS2KinesisProducer.Builder
    .default[IO](StreamNameOrArn.Name("my-stream"), client, AwsRegion.US_EAST_1)
    .withCloudWatchMetrics()
    .build
)

Backends

withCloudWatchMetrics supports two transports, selected via the backend parameter:

• CloudWatchBackend.PutMetricData (default) — the GA PutMetricData API. Works in all regions and requires no extra infrastructure.
• CloudWatchBackend.Otlp (public preview) — CloudWatch's native OTLP endpoint. Availability varies by region.

import cats.effect._
import org.http4s.blaze.client.BlazeClientBuilder
import smithy4s.aws._

import kinesis4cats.smithy4s.client.producer.KinesisProducer
import kinesis4cats.smithy4s.client.producer.opentelemetry.syntax.cloudwatch._
import kinesis4cats.models.StreamNameOrArn
import kinesis4cats.producer.metrics.cloudwatch.CloudWatchBackend

BlazeClientBuilder[IO].resource.flatMap(client =>
  KinesisProducer.Builder
    .default[IO](StreamNameOrArn.Name("my-stream"), client, AwsRegion.US_EAST_1)
    .withCloudWatchMetrics(backend = CloudWatchBackend.Otlp)
    .build
)

Configuration

withCloudWatchMetrics accepts the following parameters, all with sensible defaults: