Exporting Metrics to Prometheus in Effect with OpenTelemetry

import { Effect, Metric } from "effect"
import { NodeSdk } from "@effect/opentelemetry"
import { PrometheusExporter } from "@opentelemetry/exporter-prometheus"
import { NodeRuntime } from "@effect/platform-node"
import express from 'express'

const NodeSdkLive = NodeSdk.layer(() => ({
  resource: { serviceName: "example" },
  metricReader: new PrometheusExporter({
    port: 9464,
    endpoint: '/metrics',
  }),
}))

const requestCount = Metric.counter("request_count", {
  incremental: true,
})

const incrementCounter = Effect.gen(function* () {
  // Increment the counter by 1
  yield* requestCount(Effect.succeed(1))
  const state = yield* Metric.value(requestCount)
  console.log(state.count)
  return state.count
})

const mainProgram = Effect.sync(() => {
  const app = express()
  const port = 3000

  app.get('/', (req, res) => {
    const counterResult = Effect.runSync(incrementCounter)
    res.send('Hello World!' + counterResult) // <-- this works
  })

  app.listen(port, () => {
    console.log(`Example app listening on port ${port}`)
  })
})

const instrumented = mainProgram.pipe(Effect.provide(NodeSdkLive))

NodeRuntime.runMain(instrumented)