@ucash/vercel-ai

Helpers to gate Vercel AI SDK routes behind a U.CASH Pay payment - charge per prompt/generation with crypto or cards. Non-custodial.

Install

npm install @ucash/vercel-ai

Gate a route

// app/api/chat/route.ts
import { streamText } from 'ai';
import { openai } from '@ai-sdk/openai';
import { withPayment } from '@ucash/vercel-ai';

export async function POST(req: Request) {
  const { paid, messages } = await req.json();
  const r = await withPayment({
    paid,                              // client proves it already paid (e.g. a paid transaction id)
    charge: { cloud: process.env.UCASH_CLOUD_TOKEN!, amount: '0.05', title: 'AI generation' },
    run: async () => {
      const result = await streamText({ model: openai('gpt-4o-mini'), messages });
      return result.toDataStreamResponse();
    },
  });
  if ((r as any).status === 402) {
    return Response.json({ paymentUrl: (r as any).paymentUrl }, { status: 402 });
  }
  return r as Response;
}

The client: on a 402, send the user to paymentUrl; after they pay, retry with paid: true (and verify the transaction via your webhook before trusting it).

Set up your pay.u.cash account

1. Sign up at pay.u.cash, verify email.
2. Set receive addresses under Settings -> Addresses.
3. Create a store at Account -> Stores -> + Add Store; use the Store Cloud Token as cloud. (Set the webhook URL + verify before trusting paid.)

License

MIT.