Gemini Go SDK

go get google.golang.org/genai
go get go.opentelemetry.io/otel
go get go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp
go get go.opentelemetry.io/otel/sdk
go get go.opentelemetry.io/otel/semconv/v1.32.0

package main

import (
	"context"
	"os"
	"strings"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.32.0"
)

func phoenixTraceEndpoint(endpoint string) string {
	endpoint = strings.TrimRight(endpoint, "/")
	if strings.HasSuffix(endpoint, "/v1/traces") {
		return endpoint
	}
	return endpoint + "/v1/traces"
}

func initTracer(ctx context.Context) (*sdktrace.TracerProvider, error) {
	// Default: self-hosted Phoenix on localhost.
	// For Phoenix Cloud, set PHOENIX_COLLECTOR_ENDPOINT and PHOENIX_API_KEY.
	opts := []otlptracehttp.Option{
		otlptracehttp.WithEndpoint("localhost:6006"),
		otlptracehttp.WithURLPath("/v1/traces"),
		otlptracehttp.WithInsecure(),
	}
	if endpoint := os.Getenv("PHOENIX_COLLECTOR_ENDPOINT"); endpoint != "" {
		opts = []otlptracehttp.Option{
			otlptracehttp.WithEndpointURL(phoenixTraceEndpoint(endpoint)),
			otlptracehttp.WithHeaders(map[string]string{
				"Authorization": "Bearer " + os.Getenv("PHOENIX_API_KEY"),
			}),
		}
	}

	exporter, err := otlptracehttp.New(ctx, opts...)
	if err != nil {
		return nil, err
	}
	res, _ := resource.New(ctx, resource.WithAttributes(
		semconv.ServiceName("gemini-go-app"),
	))
	tp := sdktrace.NewTracerProvider(
		sdktrace.WithBatcher(exporter),
		sdktrace.WithResource(res),
	)
	otel.SetTracerProvider(tp)
	return tp, nil
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	semconv "go.opentelemetry.io/otel/semconv/v1.32.0"
	"go.opentelemetry.io/otel/trace"

	"google.golang.org/genai"
)

const modelName = "gemini-2.0-flash"

func main() {
	ctx := context.Background()
	tp, _ := initTracer(ctx)
	defer tp.Shutdown(ctx)

	client, _ := genai.NewClient(ctx, &genai.ClientConfig{
		APIKey:  os.Getenv("GEMINI_API_KEY"),
		Backend: genai.BackendGeminiAPI,
	})
	tracer := otel.Tracer("gemini-go-app")

	prompt := "Write a haiku about recursion."

	ctx, span := tracer.Start(ctx, "gemini.generate_content",
		trace.WithAttributes(
			attribute.String("gen_ai.system", "gemini"),
			attribute.String("gen_ai.operation.name", "chat"),
			semconv.GenAIRequestModel(modelName),
		),
	)
	defer span.End()

	resp, err := client.Models.GenerateContent(ctx, modelName, genai.Text(prompt), nil)
	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())
		return
	}

	span.SetAttributes(semconv.GenAIResponseModel(modelName))
	if usage := resp.UsageMetadata; usage != nil {
		span.SetAttributes(
			semconv.GenAIUsageInputTokens(int(usage.PromptTokenCount)),
			semconv.GenAIUsageOutputTokens(int(usage.CandidatesTokenCount)),
		)
	}
	fmt.Println(resp.Text())
}