> ## Documentation Index
> Fetch the complete documentation index at: https://forest-docs-cli-reference-headless-commands.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Upgrade to v4

> The purpose of this note is to help developers to upgrade their agent from v3 to v4. Please read carefully and integrate the following breaking changes to ensure a smooth update.​

<Warning>
  Please be aware that while Forest make every effort to ensure that our platform updates are broadly compatible and offer detailed instructions for upgrading, Forest cannot guarantee that custom code developed by the developers will always be compatible with new versions of our software. This includes any custom modifications or extensions to core functionalities, such as method overrides or custom integrations. It is the responsibility of the developers to review and test their custom code to ensure compatibility with each new version. Our team provides comprehensive upgrade guides to assist in this process, but these cannot encompass the unique customizations that may be present in each customer's environment. Therefore, Forest strongly recommend establishing a thorough testing protocol for your specific customizations to safeguard against potential issues during the upgrade process.
</Warning>

## Upgrading to v4

<Warning>
  Before upgrading to v4, consider the below **breaking changes**.
</Warning>

<Warning>
  As for any dependency upgrade, it's very important to **test this upgrade** **in your testing environments**. Not doing so could result in your admin panel being unusable.
</Warning>

To upgrade to v4, **update the version in your Gemfile**, then run:

```javascript theme={null}
bundle install
```

<Info>
  In case of a regression introduced in Production after the upgrade, a rollback to your previous agent version 3 is the fastest way to restore your admin panel.
</Info>

## Breaking changes

### New JWT authentication token

The information format of the *session token* have changed in v4.

<Info>
  You could be impacted if you use the *user session* in Smart Action controllers or Smart Routes
</Info>

**Calling `forest_user` in v3**

```javascript theme={null}
{
  "id": "172",
  "type": "users",
  "data": {
    "email": "angelicabengtsson@doha2019.com",
    "first_name": "Angelica",
    "last_name": "Bengtsson",
    "teams": ["Pole Vault"],
  },
  "relationships": {
    "renderings": {
      "data": [{
        "type": "renderings",
        "id": "4998",
      }],
    },
  },
  "iat": 1569913709,
  "exp": 1571123309
}
```

**Calling `forest_user` in v4**

```javascript theme={null}
{
  "id": "172",
  "email": "angelicabengtsson@doha2019.com",
  "firstName": "Angelica",
  "lastName": "Bengtsson",
  "team": "Pole Vault",
  "renderingId": "4998",
  "iat": 1569913709,
  "exp": 1571123309
}
```

Consequently, the user information is now accessible as described below:

| Property     | v3                                                | v4                        |
| ------------ | ------------------------------------------------- | ------------------------- |
| email        | `forest_user.data.email`                          | `forest_user.email`       |
| first name   | `forest_user.data.first_name`                     | `forest_user.firstName`   |
| last name    | `forest_user.data.last_name`                      | `forest_user.lastName`    |
| team         | `forest_user.data.teams[0]`                       | `forest_user.team`        |
| rendering id | `forest_user.relationships.renderings.data[0].id` | `forest_user.renderingId` |

### New filters query parameters format

The **query parameters** sent for **filtering** purposes have changed in v4.

<Info>
  You could be impacted if you have custom filter implementations.
</Info>

Below are a few example of the new filter conditions format you can access using`params[:filters]`:

```javascript theme={null}
{
  "field": "planLimitationReachedAt",
  "operator": "previous_year_to_date",
  "value": null
}
```

```javascript theme={null}
{
  "aggregator": "and",
  "conditions": [{
    "field": "planLimitationReachedAt",
    "operator": "previous_year_to_date",
    "value": null
  }, {
    "field": "planLimitationStatus",
    "operator": "equal",
    "value": "warning"
  }]
}
```

## Important Notice

### Agent logout

A consequence of the new session token format is:

<Warning>
  Once an agent v4 deployed, **all users of your project will be automatically logged out** and be forced to re-authenticate to generate a newly formatted token. ​
</Warning>

### Changelogs

This release note covers only the major changes. To learn more, please refer to the changelogs in our different repositories:

* [Rails changelog](https://github.com/ForestAdmin/forest-rails/blob/master/CHANGELOG.md#release-400---2019-10-04)