> ## Documentation Index
> Fetch the complete documentation index at: https://forest-chore-open-api.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Plugins

When customizing your Back-end behavior, it is quite common to have to perform the same tasks on multiple Fields and Collections.

Plugins are the answer to that need, and you are strongly encouraged to use them everywhere you notice that your customization files could benefit from code factorization.

## Using plugins

Plugins are used by either importing a module, or installing the relevant package, and then calling the `use` method.

Depending on the plugin, options may be provided.

```javascript theme={null}
import { createAgent } from '@forestadmin/agent';
import { createFileField } from '@forestadmin/plugin-aws-s3';
import { removeTimestamps } from './plugins/remove-timestamps';

// The .use() method can be called both on the agent and on collections.
createAgent()
  // Some plugins do not require options
  .use(removeTimestamps)

  // Others do
  .customizeCollection('accounts', collection =>
    collection.use(createFileField, { fieldname: 'avatar' }),
  );
```

## Writing plugins

A plugin is nothing more than an `async function` that performs customizations.

```javascript theme={null}
export async function removeTimestamps(dataSource, collection) {
  // Allow the plugin to be used both on the dataSource or on individual collections
  const collections = collection ? [collection] : dataSource.collections;

  // Remove fields
  for (const currentCollection of collections) {
    currentCollection.removeField('createdAt');
    currentCollection.removeField('updatedAt');
  }
}
```

## Write your own plugin

Each plugin is nothing more than an `async function` that can perform customizations at either Back-end level, Collection level, or both.

```javascript theme={null}
export async function removeTimestamps(dataSource, collection, options) {
  // ... call customization methods here
}
```

3 parameters are provided:

| Name         | Description                                                                                                                                                                                          |
| ------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `dataSource` | An object that allows customizing the whole agent. It has the same interface as the `Agent` you manipulate outside of plugins                                                                        |
| `collection` | An object that allows customizing the collection that the plugin was called from (`null` if the plugin was called on the Back-end). It is the same object passed when you call `customizeCollection` |
| `options`    | Options that are provided to the plugin. There is no set structure for this parameter, as each plugin will provide specific mandatory or optional options                                            |

### Making your plugin act differently depending on the collection

When making a plugin, you may want it to generalize to many different Collections.

This can be achieved by adopting different behavior depending on the `schema` of the Collection being targeted.

```javascript theme={null}
export async function removeTimestamps(dataSource, collection, options) {
  for (const currentCollection of dataSource.collections) {
    if (currentCollection.schema.fields.createdAt) {
      currentCollection.removeField('createdAt');
    }

    if (currentCollection.schema.fields.updatedAt) {
      currentCollection.removeField('updatedAt');
    }
  }
}
```