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

# Introduction

- [Overview](https://dev.simplepay.ai/docs/introduction/readme.md)
- [Core concepts](https://dev.simplepay.ai/docs/introduction/core-concepts.md)
- [Transparency](https://dev.simplepay.ai/docs/introduction/core-concepts/transparency.md)
- [Non-Custodial](https://dev.simplepay.ai/docs/introduction/core-concepts/non-custodial.md)
- [Direct payments](https://dev.simplepay.ai/docs/introduction/core-concepts/direct-payments.md)
- [Lowest Fees](https://dev.simplepay.ai/docs/introduction/core-concepts/lowest-fees.md)
- [Protocol](https://dev.simplepay.ai/docs/introduction/protocol.md)
- [Security](https://dev.simplepay.ai/docs/introduction/security.md)
- [Collected data](https://dev.simplepay.ai/docs/introduction/security/collected-data.md)