Vercel AI SDK

The Vercel AI SDK can emit OpenTelemetry spans for model calls, tools, token usage, and streaming operations. Logfire can receive those spans through either @pydantic/logfire-node in Node.js scripts or @vercel/otel in Next.js applications.

Node.js Scripts

Terminal

npm install @pydantic/logfire-node ai @ai-sdk/openai

Configure Logfire before importing the AI SDK:

instrumentation.ts

import * as logfire from '@pydantic/logfire-node'

logfire.configure({
  serviceName: 'ai-worker',
})

Enable telemetry on AI SDK calls:

import './instrumentation.ts'
import { openai } from '@ai-sdk/openai'
import { generateText } from 'ai'

const result = await generateText({
  model: openai('gpt-4.1-mini'),
  prompt: 'Write a short haiku about traces.',
  experimental_telemetry: { isEnabled: true },
})

console.log(result.text)

Next.js

In Next.js, configure @vercel/otel as shown in Next.js, then enable the same experimental_telemetry option on AI SDK calls.

Metadata

Use functionId and metadata to make traces easier to query:

await generateText({
  model,
  prompt,
  experimental_telemetry: {
    functionId: 'support-reply',
    isEnabled: true,
    metadata: {
      tenant: 'acme',
    },
  },
})