The steps to instrument the subgraphs are as follows:
1

Instrument your application with OpenTelemetry.
2

Ensure you define a unique serviceName.
3

If you’re running on Cosmo Cloud, the OTEL endpoint is https://cosmo-otel.wundergraph.com
4

Set the endpoint URL path to /v1/traces (Usually the default)
5

To authenticate against the collector, make your OpenTelemetry agent authenticate using your federated graph token as a bearer token, by adding the following HTTP header: Authorization: Bearer <your token>

​
Examples

​
Go

client := otlptracehttp.NewClient(
    otlptracehttp.WithEndpoint("https://cosmo-otel.wundergraph.com"),
    otlptracehttp.WithHeaders(map[string]string{
        "Authorization": "Bearer <secret>",
    }),
)

tp := sdktrace.NewTracerProvider(
    sdktrace.WithResource(resource.NewSchemaless(semconv.ServiceNameKey.String(otelOpts.ServiceName))),
    sdktrace.WithSampler(
	sdktrace.ParentBased(
    	    sdktrace.TraceIDRatioBased(c.Sampler),
    	    // When the parent span is sampled, the child span will be sampled.
    	),
    ),
)

​
TypeScript

import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-proto";

// Set OTEL_HTTP_ENDPOINT to https://cosmo-otel.wundergraph.com
// Set OTEL_AUTH_TOKEN to your graph authentication token
const otelAuthToken = process.env.OTEL_AUTH_TOKEN;
const otlpExporterHeaders = otelAuthToken
  ? { Authorization: `Bearer ${otelAuthToken}` }
  : undefined;

const otlpExporter = new OTLPTraceExporter({
  url: process.env.OTEL_HTTP_ENDPOINT,
  headers: otlpExporterHeaders,
});

​
Sampling Rate

Ensure that your subgraphs use parent-based sampling to inherit the sampling rate.

​
Example

Additionally, check our TypeScript example with OTEL.
Custom OTEL Metrics are currently not exposed but stored. Please contact us if you have advanced use cases.