> For the complete documentation index, see [llms.txt](https://docs.payengine.co/merchant-api-reference/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payengine.co/merchant-api-reference/introduction.md).

# Introduction

Our API adheres to REST principles, featuring predictable, resource-oriented URLs. It utilizes JSON for request and response formats, and employs standard HTTP response codes, authentication mechanisms, and verbs. \
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Exceptions to this standard, where an API is specifically designed to return a particular resource type, will be clearly documented.