Next.js already traces your requests. Here's how to export them with OpenTelemetry.

Summary

Next.js provides out-of-the-box tracing for incoming requests, fetch calls, middleware, and server-side rendering, but traces remain invisible without a configured exporter. Developers can use the @vercel/otel package inside an instrumentation file to initialize the OpenTelemetry SDK and transmit traces to any OTLP-compatible destination. While Next.js automatically creates spans for standard request lifecycles, developers can define custom active spans in the Node runtime to capture specific domain operations and contextual attributes. Exporting traces to backends like Sentry requires configuring standard OTLP endpoint and authentication environment variables. Choosing between direct OTLP export via @vercel/otel and the dedicated Sentry SDK depends on requirements, as direct export lacks browser tracing, error monitoring, and Edge custom spans.

Takeaways

1. 1

   @vercel/otel configures the OpenTelemetry SDK across Node and Edge runtimes, automatically loaded through Next.js startup via the register function in instrumentation.ts.

2. 2

   Custom spans created via @opentelemetry/api allow developers to track domain logic and attach attributes, but @vercel/otel only supports custom spans in the Node runtime, not the Edge runtime.

3. 3

   Direct OTLP exporting via @vercel/otel avoids SDK overhead but omits browser tracing, error monitoring, session replay, and source-mapped stack traces provided by @sentry/nextjs.