Next.js

Run Tailrace with the Vercel AI SDK in a Next.js App Router route - block secrets, tokenize PII, restore at egress.

Enforce data policy on AI SDK model calls in Next.js. Scan prompts before they reach a provider, scan completions on the way back, and restore tokenized PII at egress for your UI.

Quickstart

// app/api/chat/route.ts
import { createTailrace, PolicyViolationError } from "@tailrace/core";
import { withAiSdk } from "@tailrace/ai-sdk";
import { openai } from "@ai-sdk/openai";
import { generateText } from "ai";

const tailrace = withAiSdk(createTailrace());

export async function POST(req: Request) {
  const { prompt } = await req.json();
  const workflowId = req.headers.get("x-workflow-id") ?? crypto.randomUUID();

  const model = tailrace.model(openai("gpt-4o"), { workflowId, agent: "chat" });

  try {
    const result = await generateText({ model, prompt });
    const restored = await tailrace.restore(result.text, {
      boundary: { kind: "egress", sink: "ui" },
      identity: { agent: "chat" },
      workflowId,
    });
    return Response.json({ text: restored.output });
  } catch (err) {
    if (err instanceof PolicyViolationError) {
      return Response.json(
        { error: { type: "policy_violation", message: err.message } },
        { status: 422 },
      );
    }
    throw err;
  }
}

Boundaries covered

Location	Tailrace boundary	Direction
Request prompt → model	`{ kind: "model", provider: "openai/gpt-4o" }`	Outbound to provider
Model completion → app	Same model boundary	Inbound from provider
HTTP response → browser	`{ kind: "egress", sink: "ui" }`	Restore (explicit `restore` call)
Tool args / results	`{ kind: "tool", name, direction }`	Out / in (with `wrapTools`)

Provider strings use ${providerId}/${modelId}. Policy globs like openai/* match accordingly.

Runnable example

git clone <repo>
cd tailrace
pnpm install
pnpm --filter example-nextjs-ai-sdk dev

Open http://localhost:3000.

Button	Expected outcome
Run A - block secret	422, `entity: api_key`, secret never hits mock model
Run B - tokenize + restore	200, UI shows real email, `modelSaw` shows token

Source: examples/nextjs-ai-sdk in the monorepo.

The example sets export const runtime = "nodejs". @tailrace/core and @tailrace/ai-sdk also run on Edge when your provider and AI SDK usage are Edge-compatible. Keep vault keys in environment variables (TAILRACE_VAULT_KEY or createTailrace({ vault: { key } })).

Guides

Reference

AI SDK package