Getting started

import { createGateway } from 'ai';

const gateway = createGateway({
  apiKey: process.env.AI_GATEWAY_API_KEY,
});

import { createGatewayMiddleware } from '@ai-billing/gateway';
import { consoleDestination } from '@ai-billing/core';

const billingMiddleware = createGatewayMiddleware({
  destinations: [consoleDestination()],
});

import { wrapLanguageModel } from 'ai';

const model = 'gpt-5'; // or any other model supported by the gateway, like 'anthropic/claude-opus-4'
const wrappedModel = wrapLanguageModel({
  model: gateway(model),
  middleware: billingMiddleware,
});

import { streamText, convertToModelMessages, UIMessage } from 'ai';

const messages: UIMessage[] = [
  {
    id: 'test-message-123',
    role: 'user',
    parts: [{ type: 'text', text: 'What is the capital of Sweden?' }],
  },
];

const result = streamText({
  model: wrappedModel,
  messages: await convertToModelMessages(messages),
});

return result.toUIMessageStreamResponse();