Tracing

The SDK instruments agent runs, LLM calls, tool calls, prompt loading, and history operations with OpenTelemetry spans following the GenAI semantic conventions. Wire up a tracer provider once at startup and every agent traces itself.

Setting up a provider

telemetry.NewProvider takes any OpenTelemetry SpanExporter, installs it as the global tracer provider, and returns a shutdown function:

import (
    "github.com/hastekit/agent-sdk-go/pkg/telemetry"
    "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
)

func main() {
    exporter, err := otlptracehttp.New(context.Background(),
        otlptracehttp.WithEndpoint("otel-collector:4318"),
    )
    if err != nil {
        log.Fatal(err)
    }

    shutdown := telemetry.NewProvider(exporter)
    defer shutdown()

    // ... create agents and run them ...
}

Because it takes an exporter rather than an endpoint, any OTLP-compatible backend works — a collector, Jaeger, Honeycomb, Datadog, or your own SpanExporter implementation.

NewProvider previously took (endpoint, username, password) and built a Langfuse exporter internally. It now takes a trace.SpanExporter; use telemetry.NewLangFuseExporter to get the old behaviour.

The provider samples every span (ParentBased(AlwaysSample())), batches exports, and installs the W3C trace-context and baggage propagators so a trace started upstream carries through the agent run. Exporter and processor errors are surfaced through slog at warn level rather than OTel’s default stderr logger, so a rejected export shows up in structured logs instead of being easy to miss.

Langfuse

NewLangFuseExporter builds an OTLP exporter pointed at Langfuse’s OTel endpoint, authenticated with your public/secret key pair:

exporter, err := telemetry.NewLangFuseExporter(
    "cloud.langfuse.com", // host:port, no scheme
    os.Getenv("LANGFUSE_PUBLIC_KEY"),
    os.Getenv("LANGFUSE_SECRET_KEY"),
    true, // TLS
)
if err != nil {
    log.Fatal(err)
}

shutdown := telemetry.NewProvider(exporter)
defer shutdown()

Pass false for the last argument to talk to a self-hosted Langfuse over plain HTTP.

Durable runtimes

Under Temporal and Restate a plain context.Context does not survive the workflow/activity boundary, so each runtime re-establishes trace context on the far side — Temporal through a context propagator, Restate through the workflow input. A run’s spans stay in one trace across the boundary. Set the provider up on both the client process and the worker process; each exports its own spans.

Correlating a run

The AG-UI run lifecycle chunk carries a traceid, so a trace can be looked up from a run in your UI.

Getting started

LLM Gateway

Agents

Workflows

Setting up a provider

Langfuse

Durable runtimes

Correlating a run

​Setting up a provider

​Langfuse

​Durable runtimes

​Correlating a run

Setting up a provider

Langfuse

Durable runtimes

Correlating a run