npm package: @sentry/node-core
Description: Sentry Node-Core SDK
Author: Sentry
Latest version: 10.48.0

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# Official Sentry SDK for Node-Core

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Unlike the `@sentry/node` SDK, this SDK comes with no OpenTelemetry auto-instrumentation out of the box. It requires the following OpenTelemetry dependencies and supports both v1 and v2 of OpenTelemetry:

- `@opentelemetry/api`
- `@opentelemetry/context-async-hooks`
- `@opentelemetry/core`
- `@opentelemetry/instrumentation`
- `@opentelemetry/resources`
- `@opentelemetry/sdk-trace-base`
- `@opentelemetry/semantic-conventions`.

## Installation

```bash
npm install @sentry/node-core @sentry/opentelemetry @opentelemetry/api @opentelemetry/core @opentelemetry/context-async-hooks @opentelemetry/instrumentation @opentelemetry/resources @opentelemetry/sdk-trace-base @opentelemetry/semantic-conventions

# Or yarn
yarn add @sentry/node-core @sentry/opentelemetry @opentelemetry/api @opentelemetry/core @opentelemetry/context-async-hooks @opentelemetry/instrumentation @opentelemetry/resources @opentelemetry/sdk-trace-base @opentelemetry/semantic-conventions
```

## Usage

Sentry should be initialized as early in your app as possible. It is essential that you call `Sentry.init` before you
require any other modules in your application, otherwise any auto-instrumentation will **not** work.

You also **have to** set up OpenTelemetry, if you prefer not to, consider using the `@sentry/node` SDK instead.
Without setting up OpenTelemetry, you only get basic error tracking out of the box without proper scope isolation.

You need to create a file named `instrument.js` that imports and initializes Sentry:

```js
// CJS Syntax
const { trace, propagation, context } = require('@opentelemetry/api');
const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');
const Sentry = require('@sentry/node-core');
const { SentrySpanProcessor, SentryPropagator, SentrySampler } = require('@sentry/opentelemetry');
// ESM Syntax
import { context, propagation, trace } from '@opentelemetry/api';
import { NodeTracerProvider } from '@opentelemetry/sdk-trace-node';
import * as Sentry from '@sentry/node-core';
import { SentrySpanProcessor, SentryPropagator, SentrySampler } from '@sentry/opentelemetry';

const sentryClient = Sentry.init({
  dsn: '__DSN__',
  // ...
});

if (sentryClient) {
  // Note: This could be BasicTracerProvider or any other provider depending on how you want to use the
  // OpenTelemetry SDK
  const provider = new NodeTracerProvider({
    // Ensure the correct subset of traces is sent to Sentry
    // This also ensures trace propagation works as expected
    sampler: new SentrySampler(sentryClient),
    spanProcessors: [
      // Ensure spans are correctly linked & sent to Sentry
      new SentrySpanProcessor(),
      // Add additional processors here
    ],
  });

  trace.setGlobalTracerProvider(provider);
  propagation.setGlobalPropagator(new SentryPropagator());
  context.setGlobalContextManager(new Sentry.SentryContextManager());
}

// Set up the OpenTelemetry logger to use Sentry's logger
Sentry.setupOpenTelemetryLogger();

// validate your setup
Sentry.validateOpenTelemetrySetup();
```

You need to require or import the `instrument.js` file before importing any other modules in your application. This is
necessary to ensure that Sentry can automatically instrument all modules in your application:

```js
// Import this first!
import './instrument';

// Now import other modules
import http from 'http';

// Your application code goes here
```

### ESM Support

When running your application in ESM mode, you should use the Node.js
[`--import`](https://nodejs.org/api/cli.html#--importmodule) command line option to ensure that Sentry is loaded before
the application code is evaluated.

Adjust the Node.js call for your application to use the `--import` parameter and point it at `instrument.js`, which
contains your `Sentry.init`() code:

```bash
# Note: This is only available for Node v18.19.0 onwards.
node --import ./instrument.mjs app.mjs
```

If it is not possible for you to pass the `--import` flag to the Node.js binary, you can alternatively use the
`NODE_OPTIONS` environment variable as follows:

```bash
NODE_OPTIONS="--import ./instrument.mjs" npm run start
```

## Lightweight Mode

> [!WARNING]
> **⚠️ Experimental**: The `@sentry/node-core/light` subpath export is experimental and may receive breaking changes in minor or patch releases.

> [!IMPORTANT]
> This SDK requires Node 22.12.0+ for full functionality. If you're using lower Node versions, this SDK only offers limited tracing support. Consider using `@sentry/node` or `@sentry/node-core` instead.

If you don't need automatic spans/transactions, you can use the lightweight mode which doesn't require OpenTelemetry dependencies. This mode is ideal for when:

- you only need error tracking, logs or metrics without tracing data (no spans)
- you want to minimize bundle size and runtime overhead
- you don't need spans emitted by OpenTelemetry instrumentation

### Installation (Light Mode)

```bash
npm install @sentry/node-core

# Or yarn
yarn add @sentry/node-core
```

### Usage (Light Mode)

Import from `@sentry/node-core/light` instead of `@sentry/node-core`:

```js
// ESM
import * as Sentry from '@sentry/node-core/light';

// CJS
const Sentry = require('@sentry/node-core/light');

// Initialize Sentry BEFORE creating your HTTP server
Sentry.init({
  dsn: '__DSN__',
  // ...
});

// Then create your server (Express, Fastify, etc.)
const app = express();
```

**Important:** Initialize Sentry **before** creating your HTTP server to enable automatic request isolation.

### Features in Light Mode

**Included:**

- Error tracking and reporting
- Logs and metrics
- Automatic request isolation (Node.js 22+)
- Breadcrumbs
- Context and user data
- Local variables capture
- Distributed tracing (via `sentry-trace` and `baggage` headers)

**Not included:**

- Automatic spans/transactions (no OpenTelemetry instrumentation)

### Automatic Request Isolation

Light mode includes automatic request isolation for HTTP servers (requires Node.js 22+). This ensures that context (tags, user data, breadcrumbs) set during a request doesn't leak to other concurrent requests.

No manual middleware or `--import` flag is required - just initialize Sentry before creating your server:

```js
import * as Sentry from '@sentry/node-core/light';
import express from 'express';

// Initialize FIRST
Sentry.init({ dsn: '__DSN__' });

// Then create server
const app = express();

app.get('/error', (req, res) => {
  // This data is automatically isolated per request
  Sentry.setTag('userId', req.params.id);
  Sentry.captureException(new Error('Something went wrong'));
  res.status(500).send('Error');
});
```

### Manual Request Isolation (Node.js < 22)

If you're using Node.js versions below 22.12.0, automatic request isolation is not available. You'll need to manually wrap your request handlers with `withIsolationScope`:

```js
import * as Sentry from '@sentry/node-core/light';
import express from 'express';

Sentry.init({ dsn: '__DSN__' });

const app = express();

// Add middleware to manually isolate requests
app.use((req, res, next) => {
  Sentry.withIsolationScope(() => {
    next();
  });
});

app.get('/error', (req, res) => {
  Sentry.setTag('userId', req.params.id);
  Sentry.captureException(new Error('Something went wrong'));
  res.status(500).send('Error');
});
```

**Caveats:**

- Manual isolation prevents scope data leakage between requests
- However, **distributed tracing will not work correctly** - incoming `sentry-trace` and `baggage` headers won't be automatically extracted and propagated
- For full distributed tracing support, use Node.js 22.12.0+ or the full `@sentry/node` SDK with OpenTelemetry

## Links

- [Official SDK Docs](https://docs.sentry.io/quickstart/)