AI-billing quickstart

Start with a console destination so you can inspect usage before configuring customer billing. This example uses Vercel AI Gateway, which reports cost in its provider metadata. You do not need a Narev account or key.

Install

Use Node.js 22 or later and install AI SDK 6 with V3 middleware. Select @ai-sdk/provider@^3 explicitly so npm resolves compatible middleware types:

npm install ai@^6 @ai-sdk/provider@^3 @ai-sdk/gateway@^3 @ai-billing/gateway@^0.2 @ai-billing/core@^0.1.6
npm install --save-dev tsx

Set AI_GATEWAY_API_KEY in your server environment. The gateway can charge for inference.

Wrap your model

Create billing.ts:

import { generateText, wrapLanguageModel } from 'ai';
import { createGateway } from '@ai-sdk/gateway';
import { createGatewayV3Middleware } from '@ai-billing/gateway';
import { consoleDestination } from '@ai-billing/core';

const apiKey = process.env.AI_GATEWAY_API_KEY;
if (!apiKey) throw new Error('Set AI_GATEWAY_API_KEY');

const gateway = createGateway({ apiKey });
const model = wrapLanguageModel({
  model: gateway('openai/gpt-4o'),
  middleware: createGatewayV3Middleware({
    destinations: [consoleDestination()],
  }),
});

const result = await generateText({
  model,
  prompt: 'Explain token usage in one sentence.',
  providerOptions: {
    'ai-billing-tags': { userId: 'local-test', feature: 'quickstart' },
  },
});

console.log(result.text);

Run it with npx tsx billing.ts. Inspect the console billing event for usage, cost, and tags. Compare it with the provider’s usage record. Generating an answer alone does not prove that metering worked.

Choose a pricing source

This example uses the cost returned by the gateway. A direct provider such as OpenAI or DeepSeek can require a price resolver. Use a static map populated from verified Pricing API rates, or another compatible resolver. Static maps do not refresh themselves. Follow the DeepSeek usage guide for a complete static-map example, including cache and reasoning units. Do not assume every middleware resolves prices automatically.

Send events to a billing destination

Replace or supplement the console destination with Polar, Stripe, Lago, or OpenMeter. Use Customer Tagging from authenticated server state. Match the event’s customer identifier and numeric unit to your destination’s meter before enabling customer charges. For Polar, the default credits_consumed value is in base currency units, not nanos. See the Node.js integration for a shared server wrapper and the chatbot guide for a Next.js and Polar example.

Get started

Integrations

Package reference

AI-billing quickstart

Install

Wrap your model

Choose a pricing source

Send events to a billing destination

​Install

​Wrap your model

​Choose a pricing source

​Send events to a billing destination

Install

Wrap your model

Choose a pricing source

Send events to a billing destination