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

# Introduction

## Introduction

Welcome to **CoinCircuit**.

CoinCircuit is a crypto payment gateway for:

* Online payments
* In-store payments
* Payouts
* Refunds

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### Start here

New to CoinCircuit? Begin with [Quick Start](/introduction/quick-start.md).

### Core guides

* [Sandbox Environment](/introduction/official-sdks.md)
* [Official SDKs](/introduction/webhooks.md)
* [Authentication](/introduction/mcp-integration.md)
* [Webhooks](/introduction/error-handling.md)

### API behavior

* [Error Handling](/introduction/authentication.md)
* [Rate Limiting](/introduction/rate-limiting.md)
* [Pagination](/introduction/pagination.md)

### Developer tooling

* [MCP Integration](/introduction/sandbox-environment.md)

### Testing resources

* [Testnet Faucets](/introduction/testnet-faucets.md)