# PurchasePathInterface

Button Purchase Path takes regular Merchant URLs to products, categories or just the homepage and replaces them with a fully attributed Button Purchase Path, optimized for both conversion and user experience.
[https://developer.usebutton.com/docs/publishers-ios-app-setup#handle-link-routing-when-a-user-taps](https://developer.usebutton.com/docs/publishers-ios-app-setup#handle-link-routing-when-a-user-taps)

- `

extension
`

Sets a Purchase Path extension.

@discussion
Purchase Path Extensions is a feature designed to allow Publishers to create completely custom experiences on top of Button In-App Checkout. Purchase Path Extensions build on the rich event framework including User Activity Events & Checkout Events and communicate with users consistently through Browser Cards – a simple UX for displaying modular information throughout the shopping experience.

#### Declaration

- `

fetch(request:)
`

Fetches a Purchase Path with a Purchase Path request.

#### Declaration

#### Parameters

|     |     |
| --- | --- |
| `<br>                                request<br>` | A Purchase Path request. |
| `<br>                                purchasePathHandler<br>` | A block to be called upon completion of the Purchase Path fetch.<br>The block passes a `purchasePath` on success or an `error` if one occurred. |