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

# Getting started

> First steps with OpenAI Compatible middleware for tracking AI costs.

## Installation

```bash npm theme={null}
npm install @ai-billing/openai-compatible @ai-billing/core @ai-sdk/openai-compatible ai
```

```bash pnpm theme={null}
pnpm add @ai-billing/openai-compatible @ai-billing/core @ai-sdk/openai-compatible ai
```

```bash yarn theme={null}
yarn add @ai-billing/openai-compatible @ai-billing/core @ai-sdk/openai-compatible ai
```

## Overview

The `@ai-billing/openai-compatible` package provides middleware for tracking token usage and calculating costs when using any OpenAI-compatible provider (like xAI, Together AI, or Groq) with the Vercel AI SDK.

It captures OpenAI-compatible metrics, such as `internalReasoningTokens` and `inputCacheReadTokens`, ensuring that costs are accurately reflected across different providers.

## Usage

To use the middleware, wrap your OpenAI-compatible model using `wrapLanguageModel` from the `ai` package and pass the `createOpenAICompatibleMiddleware`.

**1. Initialize the OpenAI Compatible provider**

First, set up the provider using `createOpenAICompatible`. You must specify a `name` which will be used as the `providerId` in the middleware.

```typescript theme={null}
import { createOpenAICompatible } from '@ai-sdk/openai-compatible';

const xai = createOpenAICompatible({
  name: 'xai', // must match the providerId used in the middleware
  baseURL: 'https://api.x.ai/v1',
  apiKey: process.env.XAI_API_KEY,
});
```

**2. Define model pricing**

Set up a price resolver to define the costs for the models you'll be using. You can specify costs for standard prompt/completion tokens, as well as provider-specific metrics like `internalReasoningTokens` or `inputCacheReadTokens`.

```typescript theme={null}
import { createObjectPriceResolver } from '@ai-billing/core';

const priceResolver = createObjectPriceResolver({
  'grok-4-1-fast-reasoning': {
    promptTokens: 0.0000002,
    completionTokens: 0.0000005,
    internalReasoningTokens: 0,
    inputCacheReadTokens: 0.00000015,
  },
});
```

**3. Create the billing middleware**

Initialize the OpenAI Compatible billing middleware. You need to provide a destination (such as `consoleDestination`), your `priceResolver`, and the `providerId` that matches the `name` you used when creating the provider.

```typescript theme={null}
import { createOpenAICompatibleMiddleware } from '@ai-billing/openai-compatible';
import { consoleDestination } from '@ai-billing/core';

const billingMiddleware = createOpenAICompatibleMiddleware({
  destinations: [consoleDestination()],
  priceResolver: priceResolver,
  providerId: 'xai', // Must match the provider name used in createOpenAICompatible
});
```

**4. Wrap the model**

Use `wrapLanguageModel` from the `ai` package to apply the billing middleware to your OpenAI-compatible model.

```typescript theme={null}
import { wrapLanguageModel } from 'ai';

const wrappedModel = wrapLanguageModel({
  model: xai('grok-4-1-fast-reasoning'),
  middleware: billingMiddleware,
});
```

**5. Use the wrapped model**

Finally, use the wrapped model with AI SDK functions like `generateText` or `streamText`. The billing middleware will automatically track tokens, handle provider-specific metrics, and calculate costs.

```typescript theme={null}
import { generateText } from 'ai';

const result = await generateText({
  model: wrappedModel,
  prompt: 'What is the capital of Sweden?',
});
```


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