Send OpenTelemetry data from a Next.js app to Axiom

OpenTelemetry provides a standardized way to collect and export telemetry data from your Next.js apps. This guide walks you through the process of configuring OpenTelemetry in a Next.js app to send traces to Axiom using the OpenTelemetry SDK.

Prerequisites

Create an Axiom account.
Create a dataset in Axiom where you send your data.
Create an API token in Axiom with permissions to create, read, update, and delete datasets.
Install Node.js version 14 or newer.
An existing Next.js app. Alternatively, use the provided example project.

Initial setup

For initial setup, choose one of the following options:

Use the @vercel/otel package for easier setup.
Set up your app without the @vercel/otel package.

Initial setup with @vercel/otel

To use the @vercel/otel package for easier setup, run the following command to install the dependencies:

npm install @vercel/otel @opentelemetry/exporter-trace-otlp-http @opentelemetry/sdk-trace-node

Create an instrumentation.ts file in the root of your project with the following content:

import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { SimpleSpanProcessor } from '@opentelemetry/sdk-trace-node';
import { registerOTel } from '@vercel/otel';

export function register() {
  registerOTel({
    serviceName: 'nextjs-app',
    spanProcessors: [
      new SimpleSpanProcessor(
        new OTLPTraceExporter({
          url: 'https://api.axiom.co/v1/traces',
          headers: {
            Authorization: `Bearer ${process.env.API_TOKEN}`,
            'X-Axiom-Dataset': `${process.env.DATASET_NAME}`,
          },
        })
      ),
    ],
  });
}

Add the API_TOKEN and DATASET_NAME environment variables to your .env file. For example:

API_TOKEN=xaat-123
DATASET_NAME=my-dataset

Initial setup without @vercel/otel

To set up your app without the @vercel/otel package, run the following command to install the dependencies:

npm install @opentelemetry/sdk-node @opentelemetry/exporter-trace-otlp-http @opentelemetry/resources @opentelemetry/semantic-conventions @opentelemetry/sdk-trace-node

Create an instrumentation.ts file in the root of your project with the following content:

import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { Resource } from '@opentelemetry/resources';
import { SEMRESATTRS_SERVICE_NAME } from '@opentelemetry/semantic-conventions';
import { SimpleSpanProcessor } from '@opentelemetry/sdk-trace-node';

export function register() {
  const sdk = new NodeSDK({
    resource: new Resource({
      [SEMRESATTRS_SERVICE_NAME]: 'nextjs-app',
    }),
    spanProcessor: new SimpleSpanProcessor(
      new OTLPTraceExporter({
        url: 'https://api.axiom.co/v1/traces',
        headers: {
          Authorization: `Bearer ${process.env.API_TOKEN}`,
          'X-Axiom-Dataset': process.env.DATASET_NAME,
        },
      })
    ),
  });

  sdk.start();
}

Add the API_TOKEN and DATASET_NAME environment variables to your .env file. For example:

API_TOKEN=xaat-123
DATASET_NAME=my-dataset

Set up the Next.js environment

layout.tsx

In the src/app/layout.tsx file, import and call the register function from the instrumentation module:

import { register } from '../../instrumentation';

register();

export default function RootLayout({ children }: Readonly<{ children: React.ReactNode }>) {
  return (
    <html lang="en">
      <body>{children}</body>
    </html>
  );
}

This file sets up the root layout for your Next.js app and initializes the OpenTelemetry instrumentation by calling the register function.

route.ts

Create a route.ts file in src/app/api/rolldice/ to handle HTTP GET requests to the /rolldice API endpoint:

// src/app/api/rolldice/route.ts

import { NextResponse } from 'next/server';

function getRandomNumber(min: number, max: number): number {
  return Math.floor(Math.random() * (max - min) + min);
}

export async function GET() {
  const diceRoll = getRandomNumber(1, 6);
  return NextResponse.json(diceRoll.toString());
}

This file defines a route handler for the /rolldice endpoint, which returns a random number between 1 and 6.

next.config.js

Configure the next.config.js file to enable instrumentation and resolve the tls module:

module.exports = {
  experimental: {
    // Enable the instrumentation hook for collecting telemetry data
    instrumentationHook: true,
  },
  webpack: (config, { isServer }) => {
    if (!isServer) {
      config.resolve.fallback = {
        // Disable the 'tls' module on the client side
        tls: false,
      };
    }
    return config;
  },
};

This configuration enables the instrumentation hook and resolves the tls module for the client-side build.

tsconfig.json

Add the following options to your tsconfig.json file to ensure compatibility with OpenTelemetry and Next.js:

{
  "compilerOptions": {
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "strict": true,
    "noEmit": true,
    "esModuleInterop": true,
    "module": "esnext",
    "moduleResolution": "bundler",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "jsx": "preserve",
    "incremental": true,
    "plugins": [
      {
        "name": "next"
      }
    ],
    "paths": {
      "@/*": ["./src/*"]
    }
  },
  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
  "exclude": ["node_modules"]
}

This file configures the TypeScript compiler options for your Next.js app.

Project structure

After completing the steps above, the project structure of your Next.js app is the following:

my-nextjs-app/
  ├── src/
  │   ├── app/
  │   │   ├── api/
  │   │   │   └── rolldice/
  │   │   │       └── route.ts
  │   │   ├── page.tsx
  │   │   └── layout.tsx
  │   └── ...
  ├── instrumentation.ts
  ├── next.config.js
  ├── tsconfig.json
  └── ...

Run the app and observe traces in Axiom

Use the following command to run your Next.js app with OpenTelemetry instrumentation in development mode:

npm run dev

This command starts the Next.js development server, and the OpenTelemetry instrumentation automatically collects traces. As you interact with your app, traces are sent to Axiom where you can monitor and analyze your app’s performance and behavior.

In Axiom, go to the Stream tab and click your dataset. This page displays the traces sent to Axiom and lets you monitor and analyze your app’s performance and behavior.

Go to the Dashboards tab and click OpenTelemetry Traces. This pre-built traces dashboard provides further insights into the performance and behavior of your app.

Send data from an existing Next.js project

Manual instrumentation

Manual instrumentation allows you to create, configure, and manage spans and traces, providing detailed control over telemetry data collection at specific points within the app.

Set up and retrieve a tracer from the OpenTelemetry API. This tracer starts and manages spans within your app components or API routes.

import { trace } from '@opentelemetry/api';
const tracer = trace.getTracer('nextjs-app');

Manually start a span at the beginning of significant operations or transactions within your Next.js app and ensure you end it appropriately. This approach is for tracing specific custom events or operations not automatically captured by instrumentations.

const span = tracer.startSpan('operationName');
try {
  // Perform your operation here
} finally {
  span.end();
}

Enhance the span with additional information such as user details or operation outcomes, which can provide deeper insights when analyzing telemetry data.

span.setAttribute('user_id', userId);
span.setAttribute('operation_status', 'success');

Automatic instrumentation

Automatic instrumentation uses the capabilities of OpenTelemetry to automatically capture telemetry data for standard operations such as HTTP requests and responses.

Use the OpenTelemetry Node SDK to configure your app to automatically instrument supported libraries and frameworks. Set up NodeSDK in an instrumentation.ts file in your project.

import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';

export function register() {
  const sdk = new NodeSDK({
    resource: new Resource({ [SEM_RESOURCE_ATTRIBUTES.SERVICE_NAME]: 'nextjs-app' }),
    spanProcessor: new BatchSpanProcessor(
      new OTLPTraceExporter({
        url: 'https://api.axiom.co/v1/traces',
        headers: {
          Authorization: `Bearer ${process.env.API_TOKEN}`,
          'X-Axiom-Dataset': `${process.env.DATASET_NAME_NAME}`,
        },
      })
    ),
  });

  sdk.start();
}

Include necessary OpenTelemetry instrumentation packages to automatically capture telemetry from Node.js libraries like HTTP and any other middlewares used by Next.js.
Call the register function from the instrumentation.ts within your app startup file or before your app starts handling traffic to initialize the OpenTelemetry instrumentation.

// In pages/_app.js or an equivalent entry point
import { register } from '../instrumentation';
register();

Reference

List of OpenTelemetry trace fields

Field Category	Field Name	Description
General Trace Information
	_rowId	Unique identifier for each row in the trace data.
	_sysTime	System timestamp when the trace data was recorded.
	_time	Timestamp when the actual event being traced occurred.
	trace_id	Unique identifier for the entire trace.
	span_id	Unique identifier for the span within the trace.
	parent_span_id	Unique identifier for the parent span within the trace.
HTTP Attributes
	attributes.http.method	HTTP method used for the request.
	attributes.http.status_code	HTTP status code returned in response.
	attributes.http.route	Route accessed during the HTTP request.
	attributes.http.target	Specific target of the HTTP request.
Custom Attributes
	attributes.custom["next.route"]	Custom attribute defining the Next.js route.
	attributes.custom["next.rsc"]	Indicates if React Server Components are used.
	attributes.custom["next.span_name"]	Custom name of the span within Next.js context.
	attributes.custom["next.span_type"]	Type of the Next.js span, describing the operation context.
Resource Process Attributes
	resource.process.pid	Process ID of the Node.js app.
	resource.process.runtime.description	Description of the runtime environment. For example, Node.js.
	resource.process.runtime.name	Name of the runtime environment. For example, nodejs.
	resource.process.runtime.version	Version of the runtime environment For example, 18.17.0.
	resource.process.executable.name	Executable name running the process. For example, next-server.
Resource Host Attributes
	resource.host.arch	Architecture of the host machine. For example, arm64.
	resource.host.name	Name of the host machine. For example, MacBook-Pro.local.
Operational Details
	duration	Time taken for the operation.
	kind	Type of span (for example, server, internal).
	name	Name of the span, often a high-level title for the operation.
Scope Attributes
	scope.name	Name of the scope for the operation. For example, next.js.
	scope.version	Version of the scope. For example, 0.0.1.
Service Attributes
	service.name	Name of the service generating the trace. For example, nextjs-app.
Telemetry SDK Attributes
	telemetry.sdk.language	Language of the telemetry SDK. For example, nodejs.
	telemetry.sdk.name	Name of the telemetry SDK. For example, opentelemetry.
	telemetry.sdk.version	Version of the telemetry SDK. For example, 1.23.0.

List of imported libraries

@opentelemetry/api The core API for OpenTelemetry in JavaScript, providing the necessary interfaces and utilities for tracing, metrics, and context propagation. In the context of Next.js, it allows developers to manually instrument custom spans, manipulate context, and access the active span if needed.

@opentelemetry/exporter-trace-otlp-http This exporter enables your Next.js app to send trace data over HTTP to any backend that supports the OTLP (OpenTelemetry Protocol), such as Axiom. Using OTLP ensures compatibility with a wide range of observability tools and standardizes the data export process.

@opentelemetry/resources This defines the Resource which represents the entity producing telemetry. In Next.js, Resources can be used to describe the app (for example, service name, version) and are attached to all exported telemetry, aiding in identifying data in backend systems.

@opentelemetry/sdk-node

The OpenTelemetry SDK for Node.js which provides a comprehensive set of tools for instrumenting Node.js apps. It includes automatic instrumentation for popular libraries and frameworks, as well as APIs for manual instrumentation. In the Next.js setup, it’s used to configure and initialize the OpenTelemetry SDK.

@opentelemetry/semantic-conventions A set of standard attributes and conventions for describing resources, spans, and metrics in OpenTelemetry. By adhering to these conventions, your Next.js app’s telemetry data becomes more consistent and interoperable with other OpenTelemetry-compatible tools and systems.

@vercel/otel A package provided by Vercel that simplifies the setup and configuration of OpenTelemetry for Next.js apps deployed on the Vercel platform. It abstracts away some of the boilerplate code and provides a more streamlined integration experience.