go.opentelemetry.io/otel/sdk/metric v1.39.0: NewManualReader, NewMeterProvider, WithReader

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:0a5276bb521b1c01890d91fb42e4e002111cf96cd8a0490b290de22b5a5a6243","contract":["NewManualReader creates a non-nil manual metric reader for collecting in-memory ResourceMetrics","NewMeterProvider configures a MeterProvider with WithReader to register meters and record metric measurements","ManualReader.Collect accumulates recorded counter measurements into ResourceMetrics","MeterProvider.Shutdown gracefully stops the provider and causes subsequent Collect calls on the reader to return an error"],"goal":"verify pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"],"schemaVersion":1,"symbols":["NewManualReader","NewMeterProvider","WithReader"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","runtime":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0","symbols":["NewManualReader","NewMeterProvider","WithReader"],"verifierAdapter":"golang@1"}

module example.com/metric-sample

go 1.24.0

require (
	go.opentelemetry.io/otel v1.39.0
	go.opentelemetry.io/otel/metric v1.39.0
	go.opentelemetry.io/otel/sdk/metric v1.39.0
)

require (
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/uuid v1.6.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel/sdk v1.39.0 // indirect
	go.opentelemetry.io/otel/trace v1.39.0 // indirect
	golang.org/x/sys v0.39.0 // indirect
)

github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/otel v1.39.0 h1:8yPrr/S0ND9QEfTfdP9V+SiwT4E0G7Y5MO7p85nis48=
go.opentelemetry.io/otel v1.39.0/go.mod h1:kLlFTywNWrFyEdH0oj2xK0bFYZtHRYUdv1NklR/tgc8=
go.opentelemetry.io/otel/metric v1.39.0 h1:d1UzonvEZriVfpNKEVmHXbdf909uGTOQjA0HF0Ls5Q0=
go.opentelemetry.io/otel/metric v1.39.0/go.mod h1:jrZSWL33sD7bBxg1xjrqyDjnuzTUB0x1nBERXd7Ftcs=
go.opentelemetry.io/otel/sdk v1.39.0 h1:nMLYcjVsvdui1B/4FRkwjzoRVsMK8uL/cj0OyhKzt18=
go.opentelemetry.io/otel/sdk v1.39.0/go.mod h1:vDojkC4/jsTJsE+kh+LXYQlbL8CgrEcwmt1ENZszdJE=
go.opentelemetry.io/otel/sdk/metric v1.39.0 h1:cXMVVFVgsIf2YL6QkRF4Urbr/aMInf+2WKg+sEJTtB8=
go.opentelemetry.io/otel/sdk/metric v1.39.0/go.mod h1:xq9HEVH7qeX69/JnwEfp6fVq5wosJsY1mt4lLfYdVew=
go.opentelemetry.io/otel/trace v1.39.0 h1:2d2vfpEDmCJ5zVYz7ijaJdOF59xLomrvj7bjt6/qCJI=
go.opentelemetry.io/otel/trace v1.39.0/go.mod h1:88w4/PnZSazkGzz/w84VHpQafiU4EtqqlVdxWy+rNOA=
golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
	otelmetric "go.opentelemetry.io/otel/metric"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"
)

func main() {
	ctx := context.Background()

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(
		sdkmetric.WithReader(reader),
	)
	defer func() {
		if err := mp.Shutdown(ctx); err != nil {
			fmt.Fprintf(os.Stderr, "shutdown error: %v\n", err)
		}
	}()

	meter := mp.Meter("sample-meter")
	counter, err := meter.Int64Counter("requests_total")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create counter: %v\n", err)
		os.Exit(1)
	}

	counter.Add(ctx, 1, otelmetric.WithAttributes(attribute.String("path", "/api")))

	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err != nil {
		fmt.Fprintf(os.Stderr, "collect failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Printf("Collected %d scope metrics successfully.\n", len(rm.ScopeMetrics))
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
	otelmetric "go.opentelemetry.io/otel/metric"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"
)

func main() {
	ctx := context.Background()

	reader := sdkmetric.NewManualReader()
	if reader == nil {
		fmt.Fprintf(os.Stderr, "FAIL: NewManualReader returned nil\n")
		os.Exit(1)
	}

	mp := sdkmetric.NewMeterProvider(
		sdkmetric.WithReader(reader),
	)
	if mp == nil {
		fmt.Fprintf(os.Stderr, "FAIL: NewMeterProvider returned nil\n")
		os.Exit(1)
	}

	meter := mp.Meter("test-metric-meter")
	counter, err := meter.Int64Counter("items_processed")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Int64Counter creation failed: %v\n", err)
		os.Exit(1)
	}

	attrs := []attribute.KeyValue{
		attribute.String("status", "ok"),
	}
	counter.Add(ctx, 10, otelmetric.WithAttributes(attrs...))
	counter.Add(ctx, 5, otelmetric.WithAttributes(attrs...))

	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: reader.Collect failed: %v\n", err)
		os.Exit(1)
	}

	if len(rm.ScopeMetrics) != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected 1 ScopeMetrics, got %d\n", len(rm.ScopeMetrics))
		os.Exit(1)
	}
	if rm.ScopeMetrics[0].Scope.Name != "test-metric-meter" {
		fmt.Fprintf(os.Stderr, "FAIL: unexpected scope name: %s\n", rm.ScopeMetrics[0].Scope.Name)
		os.Exit(1)
	}
	if len(rm.ScopeMetrics[0].Metrics) != 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected 1 metric, got %d\n", len(rm.ScopeMetrics[0].Metrics))
		os.Exit(1)
	}
	sumData, ok := rm.ScopeMetrics[0].Metrics[0].Data.(metricdata.Sum[int64])
	if !ok {
		fmt.Fprintf(os.Stderr, "FAIL: expected metricdata.Sum[int64]\n")
		os.Exit(1)
	}
	if len(sumData.DataPoints) != 1 || sumData.DataPoints[0].Value != 15 {
		fmt.Fprintf(os.Stderr, "FAIL: expected sum 15, got %v\n", sumData.DataPoints)
		os.Exit(1)
	}

	if err := mp.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: mp.Shutdown failed: %v\n", err)
		os.Exit(1)
	}

	var postShutdownRm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &postShutdownRm); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error collecting after shutdown, got nil\n")
		os.Exit(1)
	}

	fmt.Println("PASS: OpenTelemetry metric SDK contract passed")
}