> This page is for version v2 (default).
> For other versions, use one of these documentation indexes:
> - v2 (default): https://developers.clearpay.co.uk/v-2/llms.txt
> - v1: https://developers.clearpay.co.uk/v-1/llms.txt

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

# User-Agent Header

> What is a User-Agent and why do I need to have one?

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

A User-Agent header is used by the Clearpay team to identify which merchant website, and platform, API requests are coming from. You can use the form below to help generate your User-Agent header.

<form>
  Clearpay Plugin

  Platform

  System Information

  Merchant ID

  For sandbox testing use your sandbox Merchant ID. Remember to update
  this when deploying to production.

   

  Merchant Website URL

  User Agent:
</form>