strapi/docs/3.0.0-beta.x/guides/controllers.md

# Controllers

See the [controllers' concepts](../concepts/concepts.md#controllers) for details.

## Core controllers

When you create a new Content type or a new model. You will see a new empty controller as been created. It is because Strapi builds a generic api for your models by default and allows you to override and extend it in the generated files.

### Extending a Model Controller

Here are the core methods (and there current implementation).
You can simply copy and paste this code in your own controller file to customize the methods.

#### `find`

```js
module.exports = {
  /**
   * Retrieve records.
   *
   * @return {Object|Array}
   */

  find(ctx) {
    if (ctx.query._q) {
      return service.search(ctx.query);
    }
    return service.find(ctx.query);
  },
};
```

## Custom controllers

You can also add controller outisde of Content Types to build custom business logic and Api endpoints.

### Creating a custom controller?

There are two ways to create a controller:

- Using the CLI `strapi generate:controller products`. Read the [CLI documentation](../cli/CLI.md#strapi-generatecontroller) for more information.
- Manually create a JavaScript file in `./api/**/controllers`.

### Adding Endpoints

Each controller’s action must be an `async` function.
Every action receives a `context` (`ctx`) object as first parameter containing the [request context](../guides/requests.md) and the [response context](../guides/responses.md).

::: note
Every action must be referenced by a route.
:::

### Example

In this example, we are defining a specific route in `./api/hello/config/routes.json` that takes `Hello.index` as handler.

It means that every time a request `GET /hello` is sent to the server, Strapi will call the `index` action in the `Hello.js` controller.
Our `index` action will return `Hello World!`. You can also return a JSON object.

**Path —** `./api/hello/config/routes.json`.

```json
{
  "routes": [
    {
      "method": "GET",
      "path": "/hello",
      "handler": "Hello.index"
    }
  ]
}
```

**Path —** `./api/hello/controllers/Hello.js`.

```js
module.exports = {
  // GET /hello
  index: async ctx => {
    ctx.send('Hello World!');
  },
};
```

::: note
A route handler can only access the controllers defined in the `./api/**/controllers` folders.
:::