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What is Vercel AI SDK tracing?

This guide shows how to set up Respan tracing with Next.js and the Vercel AI SDK so you can monitor and trace your AI-powered applications.

Steps to use

If you already have a Next.js + Vercel AI SDK app, start from Step 1 below.
1

Install Respan exporter

Install the Respan exporter package:
npm install @respan/exporter-vercel
2

Set up OpenTelemetry instrumentation

Next.js supports OpenTelemetry instrumentation out of the box. Create instrumentation.ts in your project root (where package.json lives).Install Vercel’s OpenTelemetry instrumentation:
yarn add @vercel/otel
Then configure the Respan exporter:
instrumentation.ts
import { registerOTel } from "@vercel/otel";
import { RespanExporter } from "@respan/exporter-vercel";

export function register() {
  registerOTel({
    serviceName: "next-app",
    traceExporter: new RespanExporter({
      apiKey: process.env.RESPAN_API_KEY,
      baseUrl: process.env.RESPAN_BASE_URL,
      debug: true,
    }),
  });
}
3

Configure environment variables

Add your Respan credentials (and your provider key) to .env.local:
.env.local
OPENAI_API_KEY=your_openai_api_key_here

RESPAN_API_KEY=your_respan_api_key_here
RESPAN_BASE_URL=https://api.respan.ai
4

Enable telemetry in your route

In your API route file (e.g. app/api/chat/route.ts), enable telemetry by adding the experimental_telemetry option.
app/api/chat/route.ts
import { openai } from "@ai-sdk/openai";
import { streamText } from "ai";

export const maxDuration = 30;

export async function POST(req: Request) {
  const { messages, id } = await req.json();
  console.log("chat id", id);

  const result = streamText({
    model: openai("gpt-4o"),
    messages,
    experimental_telemetry: {
      isEnabled: true,
      metadata: {
        customer_identifier: "customer_from_metadata",
      },
    },
  });

  return result.toDataStreamResponse();
}
5

Run locally and verify traces

  1. Start your dev server:
pnpm dev
  1. Make some chat requests through your application
  2. Verify traces in Respan:
    • Go to Logs → Traces in your Respan dashboard
    • Confirm requests are being traced
If you hit missing dependency errors from @vercel/otel, install the missing packages and retry.

What gets traced

With this setup, Respan will capture:
  • AI model calls: requests made via the Vercel AI SDK
  • Token usage: input and output token counts
  • Performance metrics: latency and throughput
  • Errors: failed requests and error details
  • Custom metadata: additional context you attach via telemetry metadata