> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fact0.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Vercel AI SDK

> Audit AI route handlers and stream LLM telemetry from Vercel AI SDK apps.

# Vercel AI SDK

Use `@fact0/sdk` from any Next.js route handler or Vercel Function.

## Install

```bash theme={null}
npm install @fact0/sdk
```

## Server-side audit + telemetry

```typescript theme={null}
import { streamText } from "ai";
import { openai } from "@ai-sdk/openai";
import { Fact0Client } from "@fact0/sdk";

const lf = new Fact0Client({ apiKey: process.env.FACT0_API_KEY! });

export async function POST(req: Request) {
  const { prompt, userId } = await req.json();

  await lf.audit.log({
    actor: { id: userId, type: "human" },
    action: "chat.message.send",
    resource: { id: prompt.id, type: "message" },
    outcome: "success",
  });

  const result = await streamText({
    model: openai("gpt-4o"),
    prompt: prompt.text,
  });

  return result.toAIStreamResponse();
}
```

## Stream telemetry

Wrap `streamText` calls in a telemetry execution to record latency and token counts.

<Warning>
  Never expose `f0_live_*` keys in client code. `@fact0/sdk` is server-only.
</Warning>

## Related

* [TypeScript SDK](/sdk/typescript/installation)
* [Next.js](/integrations/nextjs)