Fastify OpenTelemetry instrumentation

This guide instruments a Fastify server with the OpenTelemetry Node.js SDK. The auto-instrumentations capture spans for every route, hook, and outbound call, and the OTLP exporters send traces, metrics, and logs to Osuite.

Fastest path. Run this in your AI IDE and the Instrumentation Agent wires this service up for you.

/osuite-instrument fastify

Prefer to do it by hand? Follow the manual steps below — they are the complete path.

Prerequisites

• Node.js 18 or newer.
• Fastify 4 or newer.
• An Osuite ingest token from Settings → API Keys.

Instrument the service

1. Install the OpenTelemetry packages

   npm install @opentelemetry/sdk-node \
     @opentelemetry/auto-instrumentations-node \
     @opentelemetry/exporter-trace-otlp-proto \
     @opentelemetry/exporter-metrics-otlp-proto \
     @opentelemetry/exporter-logs-otlp-proto

   The Fastify instrumentation (@opentelemetry/instrumentation-fastify) is included in the auto-instrumentations bundle, so there is nothing extra to add.

2. Create the initialization module

   Create instrumentation.js in your project root. It is loaded before your application so the auto-instrumentations can patch Fastify as it is required.

   instrumentation.js

   const { NodeSDK } = require('@opentelemetry/sdk-node');
   const { getNodeAutoInstrumentations } = require('@opentelemetry/auto-instrumentations-node');
   const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-proto');
   const { OTLPMetricExporter } = require('@opentelemetry/exporter-metrics-otlp-proto');
   const { OTLPLogExporter } = require('@opentelemetry/exporter-logs-otlp-proto');
   const { PeriodicExportingMetricReader } = require('@opentelemetry/sdk-metrics');
   const { BatchLogRecordProcessor } = require('@opentelemetry/sdk-logs');
   
   const sdk = new NodeSDK({
     traceExporter: new OTLPTraceExporter(),
     metricReader: new PeriodicExportingMetricReader({
       exporter: new OTLPMetricExporter(),
     }),
     logRecordProcessors: [new BatchLogRecordProcessor(new OTLPLogExporter())],
     instrumentations: [getNodeAutoInstrumentations()],
   });
   
   sdk.start();
   
   process.on('SIGTERM', () => {
     sdk.shutdown().finally(() => process.exit(0));
   });

Configure and run

The exporters and resource are configured entirely through environment variables:

• OTEL_EXPORTER_OTLP_ENDPOINT — your Osuite ingest endpoint.
• OTEL_EXPORTER_OTLP_HEADERS — the x-osuite-ingest-token header that authenticates ingestion.
• OTEL_SERVICE_NAME — the service name that identifies this service in Osuite.
• OTEL_RESOURCE_ATTRIBUTES — additional resource attributes such as service.environment.

Load instrumentation.js before your app with node --require. Choose your deployment target:

Bare host

export OTEL_EXPORTER_OTLP_ENDPOINT="https://ingest.<region>.osuite.io:443"
export OTEL_EXPORTER_OTLP_HEADERS="x-osuite-ingest-token=<your-ingest-token>"
export OTEL_SERVICE_NAME="orders-api"
export OTEL_RESOURCE_ATTRIBUTES="service.environment=production"

node --require ./instrumentation.js server.js

Docker

# Dockerfile
FROM node:22-slim
WORKDIR /app
COPY package*.json ./
RUN npm ci --omit=dev
COPY . .
CMD ["node", "--require", "./instrumentation.js", "server.js"]

Pass the configuration at run time so the ingest token never lands in the image:

docker run \
  -e OTEL_EXPORTER_OTLP_ENDPOINT="https://ingest.<region>.osuite.io:443" \
  -e OTEL_EXPORTER_OTLP_HEADERS="x-osuite-ingest-token=<your-ingest-token>" \
  -e OTEL_SERVICE_NAME="orders-api" \
  -e OTEL_RESOURCE_ATTRIBUTES="service.environment=production" \
  orders-api

Kubernetes

Store the ingest token in a Secret:

kubectl create secret generic osuite-ingest \
  --from-literal=otlp-headers="x-osuite-ingest-token=<your-ingest-token>"

Reference it from the Deployment and keep instrumentation.js in the start command:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: orders-api
spec:
  replicas: 1
  selector:
    matchLabels:
      app: orders-api
  template:
    metadata:
      labels:
        app: orders-api
    spec:
      containers:
        - name: orders-api
          image: orders-api:latest
          command: ["node", "--require", "./instrumentation.js", "server.js"]
          env:
            - name: OTEL_EXPORTER_OTLP_ENDPOINT
              value: "https://ingest.<region>.osuite.io:443"
            - name: OTEL_EXPORTER_OTLP_HEADERS
              valueFrom:
                secretKeyRef:
                  name: osuite-ingest
                  key: otlp-headers
            - name: OTEL_SERVICE_NAME
              value: "orders-api"
            - name: OTEL_RESOURCE_ATTRIBUTES
              value: "service.environment=production"

Framework notes

Load order matters

instrumentation.js must run before Fastify is imported. The --require flag guarantees this. Do not build your Fastify instance at module scope in the same file that starts the SDK; keep the SDK in its own instrumentation.js loaded via --require.

Note

The Fastify instrumentation records spans for route handlers and named hooks, and depends on the HTTP instrumentation (also in the bundle) for the surrounding request span. Both are enabled by default in getNodeAutoInstrumentations().

Verify in Osuite

What you should see

Send a request to your server, then open APM. The service appears within a minute under the service.name you set, emitting request-rate and latency metrics. Opening a trace shows the inbound Fastify request span with child spans for route hooks and any downstream calls.

Troubleshooting

No data in Osuite after a few minutes? Work through these checks.

• Endpoint — confirm the exporter targets exactly ingest.<region>.osuite.io:443 for your region, over TLS.
• Token — confirm the ingest header carries a valid <your-ingest-token> and has not been rotated.
• Pipeline — confirm the signal you expect (traces, logs, or metrics) is wired into an active pipeline with the otlp/osuite exporter attached.
• Export errors — check the application or Collector logs for OTLP export failures (auth, DNS, TLS, connection refused).
• Network — confirm the host has outbound access to the ingest endpoint on port 443.
• Timing — allow up to a minute for the first data to appear before assuming a failure.

Still stuck? Ask the Investigation Agent or contact support.

For Node-specific issues — ESM vs CommonJS loading, the --require flag, or missing spans — see Node.js troubleshooting.

Next steps

• Add custom spans and metrics for your business logic.
• Correlate application logs with traces.