# Introduction

> Accept crypto payments, send payouts, and issue refunds through one API.

Section: Getting Started
Source: https://coincircuit.io/docs/guides/introduction/
Interactive version: https://coincircuit.io/api-reference?tab=guides&guide=introduction

**CoinCircuit** is crypto payment infrastructure. Accept payments online, in person, and from AI agents. Bill with invoices, send payouts, and issue refunds.

## What you can build
- **Online payments.** Create a payment and redirect to a hosted checkout, or build your own UI on the API.
- **In-store payments.** Share a payment page link or QR code, or take payments on a POS terminal at the counter.
- **Invoices.** Send itemized invoices your customers pay in crypto.
- **Agentic payments (x402).** Let AI agents and automated clients pay for your API per request, settled in stablecoins with gas covered.
- **Payouts.** Withdraw your balance to a bank account or a crypto wallet.
- **Refunds.** Refund a payment or an invoice, in full or in part.
- **Deposit accounts.** Give each customer a reusable address to receive funds into their balance.
- **Webhooks.** Get a signed event the moment a payment, payout, or refund changes state.

## Base URLs
- **Production:** `https://api.coincircuit.io`
- **Sandbox:** `https://sandbox-api.coincircuit.io`

## Start here
Follow the Quick Start to take your first payment in a few minutes. To test without real funds first, set up the Sandbox.