---
title: Post-purchase extensions configuration
description: Define the capabilities and metafields for your post-purchase extension.
api_name: checkout-extensions
source_url:
  html: 'https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration'
  md: >-
    https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration.md
---

ExpandOn this page

* [How it works](https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration.md#how-it-works)
* [Anatomy of a configuration file](https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration.md#anatomy-of-a-configuration-file)

# Post-purchase extensions configuration

When you [create a post-purchase extension](https://shopify.dev/docs/apps/build/checkout/product-offers/build-a-post-purchase-offer), the `shopify.extension.toml` file is automatically generated in your extension directory. This guide describes the properties that you can configure in `shopify.extension.toml`.

***

## How it works

You define properties for your extension in the extension configuration file. The `shopify.extension.toml` file contains the extension's settings, which include the extension name and metafields.

When an extension is published to Shopify, the contents of the configuration file are pushed alongside the extension.

***

## Anatomy of a configuration file

The following example shows the properties in the `shopify.extension.toml` file:

## shopify.extension.toml

```toml
name = "post-purchase-ui"
type = "checkout_post_purchase"
uid = "cd7fff10-47a6-a6f7-60f2-c8e090f069c8fd0d2443"


# [[metafields]]
# namespace: my-namespace
# key: my-key


# [[metafields]]
# namespace: my-namespace
# key: my-key-2
```

| Property | Required? | Description |
| - | - | - |
| `type` | Yes | The type of extension. For checkout post-purchase extensions, this value is always `checkout_post_purchase`. |
| `name` | Yes | The name of the checkout post-purchase extension. |
| `metafields` | Yes | The [metafields](https://shopify.dev/docs/api/admin-graphql/latest/objects/metafield) that your extension needs to read. You can specify up to five `key` and `namespace` pairs in the configuration file. When the extension is executed, Shopify looks for the metafields in each resource and returns their contents. |

***

* [How it works](https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration.md#how-it-works)
* [Anatomy of a configuration file](https://shopify.dev/docs/api/checkout-extensions/post-purchase/configuration.md#anatomy-of-a-configuration-file)