export const metadata = {
  title: `${pageNumber} API Routes`,
}

# {metadata.title}

In this chapter, you’ll learn what API Routes are and how to create them.

## What is an API Route?

An API Route is an endpoint. It exposes commerce features to external applications, such as storefronts, the admin dashboard, or third-party systems.

The Medusa core application provides a set of admin and store API routes out-of-the-box. You can also create custom API routes to expose your custom functionalities.

---

## How to Create an API Route?

An API Route is created in a TypeScript or JavaScript file under the `src/api` directory of your Medusa application. The file’s name must be `route.ts` or `route.js`. 

![Example of API route in the application's directory structure](https://res.cloudinary.com/dza7lstvk/image/upload/v1732808645/Medusa%20Book/route-dir-overview_dqgzmk.jpg)

Each file exports API Route handler functions for at least one HTTP method (`GET`, `POST`, `DELETE`, etc…).

For example, to create a `GET` API Route at `/hello-world`, create the file `src/api/hello-world/route.ts` with the following content:

```ts title="src/api/hello-world/route.ts"
import type {
  MedusaRequest,
  MedusaResponse,
} from "@medusajs/framework/http"

export const GET = (
  req: MedusaRequest,
  res: MedusaResponse
) => {
  res.json({
    message: "[GET] Hello world!",
  })
}
```

### Test API Route

To test the API route above, start the Medusa application:

```bash npm2yarn
npm run dev
```

Then, send a `GET` request to the `/hello-world` API Route:

```bash
curl http://localhost:9000/hello-world
```

---

## When to Use API Routes

<Note title="Use API routes when" type="success">

You're exposing custom functionality to be used by a storefront, admin dashboard, or any external application.

</Note>