Introduction to PayIn

tip Status This imported reference describes the self-hosted Open gateway; confirm details against the version you run.

What is PayIn?

PayIn is a non-custodial multi-chain stablecoin payment processor that enables businesses to accept cryptocurrency payments without holding user funds.

Key Features

🌐 Multi-Chain Support: Ethereum, Polygon, Tron, Solana
💰 Stablecoin Focus: USDC, USDT, DAI
🔒 Non-Custodial: Funds go directly to your wallet
⚡ Real-Time Monitoring: Automatic payment detection
🔔 Webhooks: Event-driven notifications
🤖 AI-Powered: MCP Server for integration assistance

Getting Started Options

Choose the path that fits your needs:

Option 1: AI Assistant with MCP Server (Recommended)

Use AI to integrate PayIn through natural conversation.

Best For:

Quick exploration and learning
Developers who want AI assistance
Rapid prototyping

What You Get:

Natural language integration
AI-guided setup
Interactive troubleshooting
No code required for testing

Quick Start with MCP →

Option 2: Cloud Payment Links or Open Link Flow

PayIn Cloud includes hosted Payment Links. PayIn Open does not ship a hosted dashboard or no-code link builder; self-hosted users can create the same customer experience with the Order Payment API and their own UI.

Best For:

Small businesses
Freelancers
Event organizers
Non-technical users

What You Get:

Cloud-only hosted link creation
Open-compatible API building blocks
Shareable URL or QR-code flows
Payment tracking through API queries and webhooks

Payment Links Guide →

Option 3: Direct API Integration

Traditional REST API integration.

Best For:

Production applications
Custom implementations
Full programmatic control
Advanced integrations

What You Get:

Complete API control
Custom business logic
Production-ready
All features available

API Integration Guide →

Core Services

PayIn provides three core services for different payment scenarios:

1. Order Payment Service

One-time payment addresses for individual transactions.

How It Works:

Create order with amount and currency
Get unique payment address
User pays to address
Order completes automatically
Address released back to pool

Use Cases:

E-commerce checkout
Service payments
Invoice payments
One-time transactions

Learn more →

2. Deposit Service

Permanent addresses for recurring user payments.

How It Works:

Bind address to user ID
User gets permanent deposit address
Monitor multiple chains automatically
All deposits credited to user
Address remains bound

Use Cases:

Gaming wallets
User balance top-ups
Membership payments
Platform wallets

Learn more →

3. Cloud Payment Links or Open Link Flow

Shareable payment flows. Hosted Payment Links are a PayIn Cloud feature; PayIn Open users should build links on top of the Order Payment API.

How It Works:

Create a hosted Payment Link in PayIn Cloud, or create an order-payment flow through the API in PayIn Open
Set amount and details
Share link or QR code
User pays via link
Track with API queries and webhooks, or in your own console

Use Cases:

Event registration
Consulting invoices
Course enrollment
Freelancer payments

Learn more →

How It Works

Simple Flow

Your Application → PayIn API/MCP → Payment Address (Your Wallet)
                                           ↑
                                    User Payment
                                           ↓
                      PayIn Monitor ← Blockchain
                                           ↓
                           Webhook → Your Application

Non-Custodial Model

You control your funds:

Payments go directly to YOUR wallet addresses
PayIn only monitors blockchain transactions
You hold the private keys
You can withdraw funds anytime
Optional: Use PayIn's address management tools

Supported Technologies

Blockchains

Ethereum (Mainnet + Sepolia Testnet)
Polygon (Mainnet + Amoy Testnet)
Tron (Mainnet + Nile Testnet)
Solana (Mainnet + Devnet)

Stablecoins

USDC - Circle's USD stablecoin
USDT - Tether USD
DAI - MakerDAO stablecoin

Integration Methods

MCP Server - AI-powered integration assistant
REST API - Traditional HTTP API
Payment Links - Cloud-only hosted links; use the Order Payment API for Open-built link flows
SDKs - TypeScript, Python, PHP, Go

Use Cases

E-Commerce

Accept cryptocurrency payments in your online store with automatic order processing.

Gaming

Allow players to top up in-game currency using stablecoins from any supported blockchain.

SaaS

Process subscription payments in cryptocurrency with recurring deposit addresses.

Freelancing

Send Cloud Payment Links to clients, or generate your own Open payment pages with the Order Payment API.

Events

Sell tickets or registrations using Cloud Payment Links or a self-built Open checkout page with QR codes.

Web3 Apps

Native cryptocurrency payment processing for decentralized applications.

Next Steps

1. Choose Your Integration Path

Select one of the three options above based on your needs.

2. Understand Core Concepts

Testnet vs Mainnet - Testing and production environments
Supported Networks - Blockchain network details
Supported Tokens - Stablecoin information

3. Set Up Your System

Address Pool Setup - Configure payment addresses
Webhooks - Event notifications
Security - Best practices

Community and Support

📧 Email: support@payin.com
💬 Discord: Join our community
📚 Documentation: You're reading it!

License

PayIn is MIT licensed.

Historical hosted reference — preserved original content

This is the previous public documentation retained for context. Its Cloud / Pro service arrangements, examples and feature descriptions are historical, not current hosted PayIn promises. Use the scoped Open reference above for your own deployment.