go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.61.0: NewClientHandler

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 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler in pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler

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:sha256:38eda91aa7d7837868490f4dcbfcf553d5ccb3a961fdc9d48a7ce3ec2504e452","contract":["otelgrpc.NewClientHandler returns a non-nil stats.Handler","otelgrpc.NewClientHandler accepts configuration options including WithTracerProvider and WithMeterProvider","ClientHandler TagRPC creates and annotates context for client RPC call","ClientHandler TagConn creates and annotates context for client connection"],"goal":"verify go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler in pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0","symbols":["go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler"],"verifierAdapter":"golang@1"}

module sample

go 1.24

require (
	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.61.0
	go.opentelemetry.io/otel v1.36.0
	go.opentelemetry.io/otel/metric v1.36.0
	go.opentelemetry.io/otel/trace v1.36.0
	google.golang.org/grpc v1.72.1
)

require (
	github.com/go-logr/logr v1.4.2 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
	golang.org/x/net v0.40.0 // indirect
	golang.org/x/sys v0.33.0 // indirect
	golang.org/x/text v0.25.0 // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20250519155744-55703ea1f237 // indirect
	google.golang.org/protobuf v1.36.6 // indirect
)

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 v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
github.com/go-logr/logr v1.4.2/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/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
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 v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.61.0 h1:q4XOmH/0opmeuJtPsbFNivyl7bCt7yRBbeEm2sC/XtQ=
go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.61.0/go.mod h1:snMWehoOh2wsEwnvvwtDyFCxVeDAODenXHtn5vzrKjo=
go.opentelemetry.io/otel v1.36.0 h1:UumtzIklRBY6cI/lllNZlALOF5nNIzJVb16APdvgTXg=
go.opentelemetry.io/otel v1.36.0/go.mod h1:/TcFMXYjyRNh8khOAO9ybYkqaDBb/70aVwkNML4pP8E=
go.opentelemetry.io/otel/metric v1.36.0 h1:MoWPKVhQvJ+eeXWHFBOPoBOi20jh6Iq2CcCREuTYufE=
go.opentelemetry.io/otel/metric v1.36.0/go.mod h1:zC7Ks+yeyJt4xig9DEw9kuUFe5C3zLbVjV2PzT6qzbs=
go.opentelemetry.io/otel/sdk v1.36.0 h1:b6SYIuLRs88ztox4EyrvRti80uXIFy+Sqzoh9kFULbs=
go.opentelemetry.io/otel/sdk v1.36.0/go.mod h1:+lC+mTgD+MUWfjJubi2vvXWcVxyr9rmlshZni72pXeY=
go.opentelemetry.io/otel/sdk/metric v1.34.0 h1:5CeK9ujjbFVL5c1PhLuStg1wxA7vQv7ce1EK0Gyvahk=
go.opentelemetry.io/otel/sdk/metric v1.34.0/go.mod h1:jQ/r8Ze28zRKoNRdkjCZxfs6YvBTG1+YIqyFVFYec5w=
go.opentelemetry.io/otel/trace v1.36.0 h1:ahxWNuqZjpdiFAyrIoQ4GIiAIhxAunQR6MUoKrsNd4w=
go.opentelemetry.io/otel/trace v1.36.0/go.mod h1:gQ+OnDZzrybY4k4seLzPAWNwVBBVlF2szhehOBB/tGA=
golang.org/x/net v0.40.0 h1:79Xs7wF06Gbdcg4kdCCIQArK11Z1hr5POQ6+fIYHNuY=
golang.org/x/net v0.40.0/go.mod h1:y0hY0exeL2Pku80/zKK7tpntoX23cqL3Oa6njdgRtds=
golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250519155744-55703ea1f237 h1:cJfm9zPbe1e873mHJzmQ1nwVEeRDU/T1wXDK2kUSU34=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250519155744-55703ea1f237/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
google.golang.org/grpc v1.72.1 h1:HR03wO6eyZ7lknl75XlxABNVLLFc2PAb6mHlYh756mA=
google.golang.org/grpc v1.72.1/go.mod h1:wH5Aktxcg25y1I3w7H69nHfXdOG3UiadoBtjh3izSDM=
google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY=
google.golang.org/protobuf v1.36.6/go.mod h1:jduwjTPXsFjZGTmRluh+L6NjiWu7pchiJ2/5YcXBHnY=
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/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
	"google.golang.org/grpc/stats"
)

// ClientHandlerManager manages gRPC client instrumentation via stats.Handler.
type ClientHandlerManager struct {
	handler stats.Handler
}

// NewClientHandlerManager creates a new ClientHandlerManager configured with the given options.
func NewClientHandlerManager(opts ...otelgrpc.Option) (*ClientHandlerManager, error) {
	h := otelgrpc.NewClientHandler(opts...)
	if h == nil {
		return nil, fmt.Errorf("otelgrpc.NewClientHandler returned nil")
	}
	return &ClientHandlerManager{
		handler: h,
	}, nil
}

// Handler returns the underlying stats.Handler.
func (m *ClientHandlerManager) Handler() stats.Handler {
	if m == nil {
		return nil
	}
	return m.handler
}

// TagRPC tags a client RPC context.
func (m *ClientHandlerManager) TagRPC(ctx context.Context, info *stats.RPCTagInfo) context.Context {
	if m == nil || m.handler == nil {
		return ctx
	}
	return m.handler.TagRPC(ctx, info)
}

// TagConn tags a client connection context.
func (m *ClientHandlerManager) TagConn(ctx context.Context, info *stats.ConnTagInfo) context.Context {
	if m == nil || m.handler == nil {
		return ctx
	}
	return m.handler.TagConn(ctx, info)
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler in pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc@v0.61.0"
  ],
  "symbols": [
    "go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc.NewClientHandler"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
	"go.opentelemetry.io/otel/metric/noop"
	"go.opentelemetry.io/otel/propagation"
	traceNoop "go.opentelemetry.io/otel/trace/noop"
	"google.golang.org/grpc/stats"

	"sample"
)

func main() {
	if err := runContractTests(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All otelgrpc.NewClientHandler contract tests passed.")
}

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

	// 1. otelgrpc.NewClientHandler returns a non-nil stats.Handler
	handler := otelgrpc.NewClientHandler()
	if handler == nil {
		return fmt.Errorf("expected non-nil stats.Handler from otelgrpc.NewClientHandler")
	}
	var _ stats.Handler = handler

	// 2. otelgrpc.NewClientHandler accepts configuration options including WithTracerProvider and WithMeterProvider
	configuredHandler := otelgrpc.NewClientHandler(
		otelgrpc.WithTracerProvider(traceNoop.NewTracerProvider()),
		otelgrpc.WithMeterProvider(noop.NewMeterProvider()),
		otelgrpc.WithPropagators(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{})),
	)
	if configuredHandler == nil {
		return fmt.Errorf("expected non-nil stats.Handler from configured otelgrpc.NewClientHandler")
	}

	// 3. ClientHandler TagRPC creates and annotates context for client RPC call
	manager, err := sample.NewClientHandlerManager(
		otelgrpc.WithTracerProvider(traceNoop.NewTracerProvider()),
		otelgrpc.WithMeterProvider(noop.NewMeterProvider()),
	)
	if err != nil {
		return fmt.Errorf("NewClientHandlerManager failed: %w", err)
	}

	rpcTagInfo := &stats.RPCTagInfo{
		FullMethodName: "/sample.Service/TestMethod",
	}
	rpcCtx := manager.TagRPC(ctx, rpcTagInfo)
	if rpcCtx == nil {
		return fmt.Errorf("expected non-nil context from TagRPC")
	}

	// 4. ClientHandler TagConn creates and annotates context for client connection
	connTagInfo := &stats.ConnTagInfo{
		RemoteAddr: nil,
		LocalAddr:  nil,
	}
	connCtx := manager.TagConn(ctx, connTagInfo)
	if connCtx == nil {
		return fmt.Errorf("expected non-nil context from TagConn")
	}

	return nil
}