Tracing & OpenTelemetry

LangSmith Go supports OpenTelemetry for distributed tracing. This allows you to automatically capture and send traces from your LLM applications.

Configuration

Configure tracing using environment variables:

Variable	Description
LANGSMITH_API_KEY	Your LangSmith API key
LANGSMITH_ENDPOINT	Custom API endpoint (defaults to https://api.smith.langchain.com)
LANGSMITH_PROJECT	Project name for traces

Usage Examples

Basic OpenTelemetry Setup

import (
    "github.com/langchain-ai/langsmith-go"
    "go.opentelemetry.io/otel"
)

// Create a new tracer
tracer := langsmith.NewTracer()

// Use with OpenTelemetry
ctx, span := otel.Tracer("my-app").Start(ctx, "operation")
defer span.End()

With OpenAI

See the otel_openai example for automatic tracing of OpenAI API calls.

With Anthropic

See the otel_anthropic example for automatic tracing of Anthropic API calls.