# Monitor a Next.js app with Lampwick

> Add instrumentation.ts with @vercel/otel and point it at Lampwick. Next.js App Router requests, queries and server errors show up, over OpenTelemetry.

Next.js has OpenTelemetry built in. Add an `instrumentation.ts` that calls `@vercel/otel`, set 4 environment variables, and every server request and server-side error goes to Lampwick. We tested it with Next.js 16 (App Router, `next start`).

## What you get

- **Requests**, grouped by route, such as `GET /orders/[id]`.
- **Queries**, with the `pg` instrumentation below.
- **Issues** from server-side errors, tied to the request they happened in.

## Set it up

```bash
npm install @vercel/otel @opentelemetry/api @opentelemetry/api-logs @opentelemetry/instrumentation @opentelemetry/sdk-logs
```

Create `instrumentation.ts` in the project root (or in `src/`):

```ts
import { registerOTel } from '@vercel/otel';

export function register() {
  registerOTel({ serviceName: 'my-app' });
}
```

Set these in `.env.local`, or on Vercel under **Settings → Environment Variables**:

```dotenv
OTEL_EXPORTER_OTLP_ENDPOINT=https://app.lampwick.dev
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
OTEL_EXPORTER_OTLP_HEADERS=x-lampwick-token=YOUR_PROJECT_TOKEN
OTEL_METRICS_EXPORTER=none
```

`YOUR_PROJECT_TOKEN` is the project's ingest token, from the **Connect your app** card on its **Settings** page. For database queries, add `PgInstrumentation` (version 0.76.0); the [Next.js docs](/docs/nextjs/#database-queries) show how.

## What it doesn't do

- **Stack traces point into `.next/server/chunks/`.** Next.js bundles server code and Lampwick doesn't apply source maps. The message and the request are exact.
- **Logs aren't sent.** `console.log` isn't captured and `@vercel/otel` exports no logs.
- **Browser errors** need the [browser snippet](/integrations/browser/) as well.
- **Edge runtime**: we tested the Node.js runtime only.

## Let your agent do it

```text
Add OpenTelemetry to this Next.js app so it reports to Lampwick: follow https://lampwick.dev/docs/nextjs.md exactly (instrumentation.ts with @vercel/otel, the environment variables, PgInstrumentation only if the app uses pg). Read the ingest token from the environment, never commit it.
```

## Next step

The [Next.js docs](/docs/nextjs/) have the app we tested, what showed up and the troubleshooting table. How spans map to Lampwick: [OpenTelemetry](/docs/opentelemetry/#what-shows-up-where).