> ## Documentation Index
> Fetch the complete documentation index at: https://docs-pro.global-e.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

To implement API calls with Global-e the only required information is the `merchantGUID` provided by Global-e.

For authentication, make sure to include your Merchant GUID as part of each call or as part of the header so that Global-e can verify your identity. Make sure to use the appropriate merchantGUID, depending on the Global‑e integration environment used for development or production purposes. See [Global-e Environments](/global-e-environments).

**MerchantGUID in URL**

Add your MerchantGUID as part of each API URL.

**MerchantGUID as part of the header**

Add your MerchantGUID as part of the header as illustrated below.

```
curl --location 'https://[globale domain]/[API]' \
--header 'MerchantGUID: D2ED2A7F-F6ED-4CCB-B611-B44AC8D02250' \
--header 'Content-Type: application/json' \
--data-raw '
```

## Rotating Your Merchant GUID

Your Merchant GUID is the credential that identifies your store to Global-e, so it should be treated as a secret and replaced periodically, just as you would rotate any other API credential.

Follow the instructions for your platform below to rotate your Merchant GUID:

* [Shopify Native](/rotate-merchant-guid-shopify-native)
* [WooCommerce](/rotate-merchant-guid-woocommerce)
* [Magento 2 (M2L)](/rotate-merchant-guid-magento2-lite)
* [ShopWare](/rotate-merchant-guid-shopware)
* [BigCommerce](/rotate-merchant-guid-bigcommerce)
* [SFCC](/rotate-merchant-guid-sfcc)