import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

Now we will add a new endpoint to our Express.js app that is powered by `@nlbridge/express` library.

First, we start by adding the `@nlbridge/express` library to our project:

<Tabs groupId="package" queryString>
    <TabItem value="npm" label="NPM">
        ```bash
        npm install @nlbridge/express
        ```
    </TabItem>
    <TabItem value="yarn" label="Yarn">
        ```bash
        yarn add @nlbridge/express
        ```
    </TabItem>
    <TabItem value="pnpm" label="PNPM">
        ```bash
        pnpm install @nlbridge/express
        ```
    </TabItem>
</Tabs>

Then, modify `index.ts` file to add a new endpoint:

```typescript
import {defaultMiddleware} from '@nlbridge/express';

app.post('/chat-api',
    defaultMiddleware('openai', {
        apiKey: '<YOUR_OPENAI_API_KEY>',
        chatModel: 'gpt-3.5-turbo',
    }),
);
```

Make sure to replace `<YOUR_OPENAI_API_KEY>` with your actual OpenAI API key obtained in step 1.<br />
Then restart your server and you will have a new endpoint at **`POST`** `http://localhost:3000/chat-api` that is
powered by OpenAI's gpt-3.5-turbo model, and ready for _NLUX_ integration.

It's important to note that the new API is created with `post` method.<br />
This is a requirement for _nlbridge_ integration.