> This page is for Afterpay Online Developer, version v1.
> For other versions, use one of these documentation indexes:
> - Main (default): https://developers.afterpay.com/afterpay-online-developer/main/llms.txt
> - v1: https://developers.afterpay.com/afterpay-online-developer/v-1/llms.txt
> - Chinese: https://developers.afterpay.com/afterpay-online-developer/chinese/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://developers.afterpay.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://developers.afterpay.com/_mcp/server.

# User-Agent Header

User-Agent header must be supplied with all Merchant API requests prior to placing any live transactions.

For example:

* `MyAfterpayModule/1.0.0 (E-Commerce Platform Name/1.0.0; PHP/7.0.0; Merchant/60032000) https://merchant.example.com`

| Description          | Example Data Above               | Other Merchant Examples                                                               |
| -------------------- | -------------------------------- | ------------------------------------------------------------------------------------- |
| Afterpay Plugin      | `MyAfterpayModule/1.0.0`         | Custom Plugin/1.0  Shopify Plugin/3.5.1  AfterpayCartridge/1.0  AfterpayExtension/2.9 |
| Platform             | `E-Commerce Platform Name/1.0.0` | Websphere Commerce/8.1  Commerce Cloud/1.1  Magento/2.3.0                             |
| System Information   | `PHP/7.0.0`                      | PHP/7.2.18  Ruby/2.5.3  Java/8.3                                                      |
| Merchant Website URL | `https://merchant.example.com`   | [http://www.merchantwebsite.com](http://www.merchantwebsite.com)                      |