# Epic Games Reconcile Lambda

An overview of the Epic Games Reconcile lambda.

> For the index of this section of the site, see [llms.txt](https://fusionauth.io/docs/llms.txt)

When an Epic Games identity provider is used to complete a federated login request, FusionAuth will use the [configured linking strategy](https://fusionauth.io/docs/lifecycle/authenticate-users/identity-providers.md#linking-strategies) to reconcile the user. FusionAuth will attempt to match the user information returned from the Epic Games identity provider to an existing user account or create a new one.

You may optionally utilize a lambda to customize the user and user registration during the authentication event.

When you create a new lambda using the FusionAuth administrative user interface, you will be provided an empty function to implement.

Starting in version 1.65.0, you can use [attribute mappings](https://fusionauth.io/docs/lifecycle/authenticate-users/identity-providers.md#attribute-mappings) to map IdP claims directly to FusionAuth user and registration fields without writing a lambda. Reconcile lambdas and attribute mappings are mutually exclusive. Attempting to configure both on a given IdP results in a validation error.

## Lambda Structure

If you are using the API to create the lambda you will need to ensure your function has the following signature:

```javascript
function reconcile(user, registration, userInfo, context) {
  // Lambda code goes here
}
```

This lambda must contain a function named `reconcile` that accepts the following parameters:

*   `user` - the FusionAuth User object. You can modify this object. However, the **email** and **username** attributes may not be modified after the user has been linked.
*   `registration` - the FusionAuth UserRegistration object. You can modify this object.

*   `userInfo` - data returned by the Epic Games Account API. This object is read-only.
*   `context` - Available since `1.64.0` - an object containing the context of the request, including access to [secrets](https://fusionauth.io/docs/extend/code/lambdas.md#secrets). This object is read-only.

The two FusionAuth objects are well documented in the [User API](https://fusionauth.io/docs/apis/users.md) and [Registration API](https://fusionauth.io/docs/apis/registrations.md) documentation. The `idToken` may contain various user claims depending upon the user's Epic Games configuration.

## Assigning The Lambda

Once a lambda is created, you may assign it to the Epic Games identity provider in the IdP configuration.

Navigate to Settings -> Identity Providers and select your existing Epic Games configuration or click Add provider and select Epic Games if it has not yet been configured.
---

## Other pages in Reconcile

> For the full index of this section, see [Extend](https://fusionauth.io/docs/llms-extend.txt).

- [Apple Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/apple-reconcile.md): An overview of the Apple Reconcile lambda.
- [External JWT Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/external-jwt-reconcile.md): An overview of the External JWT Reconcile lambda.
- [Facebook Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/facebook-reconcile.md): An overview of the Facebook Reconcile lambda.
- [Google Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/google-reconcile.md): An overview of the Google Reconcile lambda.
- [HYPR Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/hypr-reconcile.md): An overview of the HYPR Reconcile lambda.
- [LDAP Connector Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/ldap-connector-reconcile.md): An overview of the LDAP Connector Reconcile lambda.
- [LinkedIn Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/linkedin-reconcile.md): An overview of the LinkedIn Reconcile lambda.
- [Nintendo Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/nintendo-reconcile.md): An overview of the Nintendo Reconcile lambda.
- [OpenID Connect Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/openid-connect-response-reconcile.md): An overview of the OpenID Connect Response Reconcile lambda.
- [SAML v2 Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/samlv2-response-reconcile.md): An overview of the SAML v2 Response Reconcile lambda.
- [Sony PlayStation Network Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/sony-playstation-network-reconcile.md): An overview of the Sony PlayStation Network Reconcile lambda.
- [Steam Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/steam-reconcile.md): An overview of the Steam Reconcile lambda.
- [Twitch Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/twitch-reconcile.md): An overview of the Twitch Reconcile lambda.
- [Twitter Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/twitter-reconcile.md): An overview of the Twitter Reconcile lambda.
- [Xbox Reconcile Lambda](https://fusionauth.io/docs/extend/code/lambdas/reconcile/xbox-reconcile.md): An overview of the Xbox Reconcile lambda.