go.opentelemetry.io/otel/sdk v1.42.0: Version, trace.NewTracerProvider, trace.WithSampler

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@v1.42.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0

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:sha256:090a30fb6f459cd9f9c01a223f612024bff4bbaa5b2473a6c7676df08eed4701","contract":["sdk.Version returns current release version 1.42.0","sdktrace.NewTracerProvider creates a functional TracerProvider with in-memory exporter","TraceExporter records started and ended spans with attributes and name","sdktrace.WithSampler supports NeverSample dropping all spans","sdktrace.WithSpanLimits enforces attribute count limits on recorded spans"],"goal":"verify pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk.Version","go.opentelemetry.io/otel/sdk/trace.NewTracerProvider","go.opentelemetry.io/otel/sdk/trace.WithSampler","go.opentelemetry.io/otel/sdk/trace.WithSpanLimits","go.opentelemetry.io/otel/sdk/trace.WithSyncer"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0","symbols":["go.opentelemetry.io/otel/sdk.Version","go.opentelemetry.io/otel/sdk/trace.NewTracerProvider","go.opentelemetry.io/otel/sdk/trace.WithSampler","go.opentelemetry.io/otel/sdk/trace.WithSpanLimits","go.opentelemetry.io/otel/sdk/trace.WithSyncer"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

require (
	go.opentelemetry.io/otel v1.42.0
	go.opentelemetry.io/otel/sdk v1.42.0
	go.opentelemetry.io/otel/trace v1.42.0
)

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/metric v1.42.0 // indirect
	golang.org/x/sys v0.41.0 // 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 v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
golang.org/x/sys v0.41.0/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 sample

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/sdk"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	"go.opentelemetry.io/otel/sdk/trace/tracetest"
	"go.opentelemetry.io/otel/trace"
)

// GetVersion returns the runtime version of the OpenTelemetry SDK.
func GetVersion() string {
	return sdk.Version()
}

// TracerConfig encapsulates TracerProvider and In-Memory Exporter.
type TracerConfig struct {
	Provider *sdktrace.TracerProvider
	Exporter *tracetest.InMemoryExporter
}

// NewTracerConfig creates a TracerProvider configured with an in-memory syncer exporter and optional options.
func NewTracerConfig(opts ...sdktrace.TracerProviderOption) *TracerConfig {
	exp := tracetest.NewInMemoryExporter()
	allOpts := append([]sdktrace.TracerProviderOption{sdktrace.WithSyncer(exp)}, opts...)
	tp := sdktrace.NewTracerProvider(allOpts...)
	return &TracerConfig{
		Provider: tp,
		Exporter: exp,
	}
}

// RecordSpan starts a span, sets given attributes, and ends it.
func (tc *TracerConfig) RecordSpan(ctx context.Context, tracerName, spanName string, attrs ...attribute.KeyValue) (trace.SpanContext, error) {
	if tc == nil || tc.Provider == nil {
		return trace.SpanContext{}, fmt.Errorf("nil tracer config or provider")
	}
	tr := tc.Provider.Tracer(tracerName)
	ctx, span := tr.Start(ctx, spanName, trace.WithAttributes(attrs...))
	sc := span.SpanContext()
	span.End()
	return sc, nil
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/sdk"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	"sample"
)

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("PASS: otel sdk v1.42.0 contract verified")
}

func runContract() error {
	ctx := context.Background()

	// 1. sdk.Version returns current release version 1.42.0
	ver := sdk.Version()
	if ver != "1.42.0" {
		return fmt.Errorf("expected sdk.Version 1.42.0, got: %s", ver)
	}
	if sampleVer := sample.GetVersion(); sampleVer != "1.42.0" {
		return fmt.Errorf("expected sample.GetVersion 1.42.0, got: %s", sampleVer)
	}

	// 2. sdktrace.NewTracerProvider creates a functional TracerProvider with in-memory exporter
	cfg := sample.NewTracerConfig(sdktrace.WithSampler(sdktrace.AlwaysSample()))
	defer cfg.Provider.Shutdown(ctx)

	// 3. TraceExporter records started and ended spans with attributes and name
	sc, err := cfg.RecordSpan(ctx, "test-tracer", "span-1", attribute.String("env", "test"), attribute.Int("val", 42))
	if err != nil {
		return fmt.Errorf("failed to record span: %w", err)
	}
	if !sc.IsValid() {
		return fmt.Errorf("expected valid span context")
	}
	spans := cfg.Exporter.GetSpans()
	if len(spans) != 1 {
		return fmt.Errorf("expected 1 span in exporter, got %d", len(spans))
	}
	if spans[0].Name != "span-1" {
		return fmt.Errorf("expected span name 'span-1', got '%s'", spans[0].Name)
	}
	if len(spans[0].Attributes) != 2 {
		return fmt.Errorf("expected 2 attributes on span, got %d", len(spans[0].Attributes))
	}

	// 4. sdktrace.WithSampler supports NeverSample dropping all spans
	neverCfg := sample.NewTracerConfig(sdktrace.WithSampler(sdktrace.NeverSample()))
	defer neverCfg.Provider.Shutdown(ctx)
	neverSC, err := neverCfg.RecordSpan(ctx, "never-tracer", "never-span")
	if err != nil {
		return fmt.Errorf("failed to record never-sampled span: %w", err)
	}
	if neverSC.IsSampled() {
		return fmt.Errorf("expected never-sampled span to have IsSampled == false")
	}
	if len(neverCfg.Exporter.GetSpans()) != 0 {
		return fmt.Errorf("expected 0 spans in exporter for NeverSample, got %d", len(neverCfg.Exporter.GetSpans()))
	}

	// 5. sdktrace.WithSpanLimits enforces attribute count limits on recorded spans
	limitsCfg := sample.NewTracerConfig(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithSpanLimits(sdktrace.SpanLimits{
			AttributeCountLimit: 1,
		}),
	)
	defer limitsCfg.Provider.Shutdown(ctx)

	_, err = limitsCfg.RecordSpan(ctx, "limits-tracer", "limits-span",
		attribute.String("k1", "v1"),
		attribute.String("k2", "v2"),
	)
	if err != nil {
		return fmt.Errorf("failed to record limit span: %w", err)
	}
	limitSpans := limitsCfg.Exporter.GetSpans()
	if len(limitSpans) != 1 {
		return fmt.Errorf("expected 1 limit span, got %d", len(limitSpans))
	}
	if limitSpans[0].DroppedAttributes != 1 {
		return fmt.Errorf("expected 1 dropped attribute, got %d", limitSpans[0].DroppedAttributes)
	}

	return nil
}