# Node.js

> https://docs.errora.org/en/platforms/node

## Install

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

## Initialize first

`Sentry.init()` must run **before** anything else is imported, so the SDK can patch `http`,
your framework and your database driver. Put it in its own file:

```javascript
// instrument.js
import * as Sentry from "@sentry/node";
import { nodeProfilingIntegration } from "@sentry/profiling-node";

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.NODE_ENV,
  release: process.env.APP_VERSION,

  tracesSampleRate: 0.2,
  profilesSampleRate: 1.0,          // fraction of sampled transactions
  integrations: [nodeProfilingIntegration()],

  _experiments: { enableLogs: true },
  sendDefaultPii: false,
});
```

Load it before your app:

```bash
node --import ./instrument.js ./server.js
```

CommonJS: `require("./instrument.js")` on the very first line of your entry file.

## Express

```javascript
import "./instrument.js";
import express from "express";
import * as Sentry from "@sentry/node";

const app = express();
// … your routes …
Sentry.setupExpressErrorHandler(app);   // after routes, before other error middleware
app.listen(3000);
```

Fastify (`Sentry.setupFastifyErrorHandler(app)`), NestJS (`@sentry/nestjs`) and Koa have
equivalent one-liners.

## Logs

```javascript
const { logger } = Sentry;
logger.info("payment captured", { orderId, amount });
logger.error("gateway rejected", { orderId, code });
```

They land in [Logs](/en/products/logs), correlated with the active trace.

## Cron check-ins

```javascript
import * as Sentry from "@sentry/node";

const checkInId = Sentry.captureCheckIn(
  { monitorSlug: "nightly-report", status: "in_progress" },
  { schedule: { type: "crontab", value: "0 3 * * *" }, checkinMargin: 5, maxRuntime: 30, timezone: "Asia/Tehran" },
);

try {
  await runNightlyReport();
  Sentry.captureCheckIn({ checkInId, monitorSlug: "nightly-report", status: "ok" });
} catch (err) {
  Sentry.captureCheckIn({ checkInId, monitorSlug: "nightly-report", status: "error" });
  throw err;
}
```

See [Cron monitoring](/en/products/crons) for schedules, margins and thresholds.

## Metrics

```javascript
Sentry.metrics.increment("checkout.attempt", 1, { tags: { plan: "pro" } });
Sentry.metrics.distribution("checkout.latency", 421, { unit: "millisecond" });
```

See [Metrics](/en/products/metrics).

## Verify

```javascript
Sentry.captureException(new Error("Errora smoke test"));
```