> For the complete documentation index, see [llms.txt](https://assetstore.essentialkit.voxelbusters.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://assetstore.essentialkit.voxelbusters.com/features/deep-link-services/playmaker/use-cases/use-case-2-oauth-callback.md).

# OAuth Authentication Callback

## Goal

Handle custom scheme URLs for OAuth authentication flow.

## Actions Required

* `DeepLinkServicesOnCustomSchemeUrlOpen`
* `DeepLinkServicesGetCustomSchemeResult`

## Variables Needed

* authToken (String)

## Implementation Steps

### 1. ListenForScheme (Persistent State)

Use `DeepLinkServicesOnCustomSchemeUrlOpen` in a persistent state.

### 2. Read Link Details

On `receivedEvent`, call `DeepLinkServicesGetCustomSchemeResult` to read:

* `rawUrl`
* `queryKeys` / `queryValues`

### 3. Extract token

Example: `myapp://oauth-callback?token=xyz`

* Find key `"token"` in `queryKeys` and take the value from `queryValues` at the same index.

### 4. Complete Authentication

Use token to finalize login, store session

## Use When

Third-party login (Facebook, Google, custom OAuth)