ZeroPay

An open-source, self-hosted x402 payment facilitator for AI agents and autonomous systems.

Features • Quick Start • Documentation • Platform • Contributing

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Overview

ZeroPay is a lightweight, self-hosted x402 payment facilitator built with Rust. It enables AI agents and autonomous systems to programmatically discover, authorize, and settle stablecoin payments using EIP-3009 gasless transfers — with no manual wallet management or blockchain infrastructure required.

Key Features

• x402 Protocol: Full Agent-to-Agent (A2A) payment protocol for autonomous AI integrations
• Gasless Payments: EIP-3009 transferWithAuthorization — payer signs off-chain, payee covers gas
• Instant Settlement: No waiting for blockchain confirmation; payment settles in one transaction
• Secure: EIP-712 typed signatures with time-bound authorization windows
• Discoverable: Agents can browse available services via /x402/discovery
• Multi-Chain: Ethereum, Polygon, Base, and other EVM-compatible networks
• Stablecoin Focused: USDC, USDT, and other EIP-3009 compatible tokens
• EIP-8004 Support: Optional agent reputation and identity registry integration
• Self-Hosted: Full control over your payment infrastructure
• Docker Ready: One-command deployment

Quick Start

Using Docker Compose (Recommended)

1. Configure your settings in docker-compose.yml:

   environment:
     - MNEMONICS=your twelve or twenty four word mnemonic phrase
     - WALLET=0xYourWalletAddress
     - APIKEY=your-secure-api-key

2. Configure blockchain in config.toml:

   [[chains]]
   chain_type = "evm"
   chain_name = "base-sepolia"
   latency = 1
   estimation = 12
   commission = 5
   commission_min = 50
   commission_max = 200
   admin = "0xYourAdminPrivateKey"
   rpc = "https://base-sepolia.g.alchemy.com/v2/YOUR-API-KEY"
   tokens = ["USDC:0xYourUSDCAddress:2"]

   The :2 suffix marks a token as x402-compatible (EIP-3009).

3. Start all services:

   docker-compose up -d

4. Verify x402 support:

   curl "http://localhost:9000/x402/support?apikey=your-api-key"

See DEPLOYMENT.md for detailed setup instructions.

Documentation

• Deployment Guide - Complete setup for Docker and source builds
• API Reference - x402 REST API endpoints and usage examples
• x402 Protocol Guide - Protocol overview and integration details
• AI Integration Guide - Complete guide for AI agents integrating with ZeroPay

How x402 Works

┌─────────────────────────────────────────────────────┐
│                   AI Agent                          │
│                                                     │
│  1. GET /x402/requirements  →  discover payee addr  │
│  2. Sign EIP-712 authorization off-chain            │
│  3. POST /x402/payments     →  settle on-chain      │
│  4. Receive tx hash + confirmation                  │
└─────────────────────────────────────────────────────┘
                        │
                        ▼
┌─────────────────────────────────────────────────────┐
│                 ZeroPay API                         │
│                                                     │
│  /x402/requirements   — payment requirements        │
│  /x402/payments       — verify + settle             │
│  /x402/support        — supported schemes           │
│  /x402/discovery      — browse available services   │
└───────────────────────┬─────────────────────────────┘
                        │ transferWithAuthorization
                        ▼
┌─────────────────────────────────────────────────────┐
│              Blockchain (EVM)                       │
│       EIP-3009 gasless token transfer               │
└─────────────────────────────────────────────────────┘

Payment flow:

1. Agent calls GET /x402/requirements with customer + amount → gets a payee address and accepted payment schemes
2. Agent creates an EIP-712 signature authorizing the transfer (off-chain, gasless for payer)
3. Agent calls POST /x402/payments with the signed authorization
4. ZeroPay verifies the signature and executes transferWithAuthorization on-chain
5. Returns transaction hash to the agent

Architecture

zeropay/
├── api/              # REST API server (Axum)
├── scanner/          # Chain scanner + x402 asset initialization
├── x402/             # x402 protocol types, facilitator, client SDK
├── config.toml       # Chain and token configuration
├── Dockerfile
└── docker-compose.yml

Development

Prerequisites

• Rust 1.75+
• PostgreSQL 12+
• Redis 6+

Build from Source

git clone https://github.com/zpaynow/zeropay.git
cd zeropay
cargo build --release
./target/release/api

Managed Platform

For a hassle-free experience, use our managed platform at zpaynow.com:

• No infrastructure management required
• Automatic updates and security patches
• Multiple chain support out of the box
• Enterprise-grade reliability

Setup: Register at zpaynow.com and use https://api.zpaynow.com as your API endpoint.

Contributing

We welcome contributions!

Reporting Vulnerabilities

Email hi@zpaynow.com instead of using the issue tracker.

Best Practices

• Never commit .env files or private keys
• Use strong, randomly generated API keys
• Keep dependencies updated
• Use secure RPC endpoints

License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

Usage Notice: This software is intended for merchant self-hosting only — to run your own payment gateway for your own store or service. It may not be used to build or operate a payment business, payment platform, or SaaS product that serves other merchants. If you need a managed solution, use zpaynow.com.