OpenPay - x402 Protocol

OPNx402

Self-hosted Facilitator for x402 on Solana

Overview

MIT Licensed

Open-source, MIT-licensed facilitator implementing the x402 payment protocol on Solana, built as a Next.js Edge API for speed, scale, and easy deploys.

OPNx402 is a clean production-ready facilitator that exposes the core x402 operations (health, supported, verify, settle) over HTTP. It is designed for self-hosting and integrates cleanly with apps that speak x402 on Solana.

Integrate

Integrate with our hosted x402 facilitator endpoint to start accepting payments without self-hosting:

Facilitator Endpoint

https://x402.openpay.network

Use this endpoint in your x402-compatible application to handle payment verification and settlement through our managed infrastructure.

Features

Edge Runtime: Runs on Next.js Edge for low-latency, global performance
x402 on Solana: Implements the facilitator flow for Solana payments
TypeScript-first: Strong types and clear error responses
CORS controls: Restrict origins via environment configuration
Production ready: Clear deploy path on Vercel or any Node/Edge host
MIT Licensed: Fully open-source for commercial and personal use

Quick Start

1. Install dependencies:

npm install

2. Create .env.local:

SOLANA_PRIVATE_KEY=your_solana_private_key_here
FACILITATOR_NETWORKS=devnet,mainnet-beta
ALLOWED_ORIGINS=https://yourdomain.com,http://localhost:3000

3. Run locally:

npm run dev

4. Build & start:

npm run build
npm start

API Endpoints

All endpoints are served under /api.

Health

GET /api/health

Returns service status and supported networks

Supported Payment Kinds

GET /api/supported

Returns available payment kinds and fee payer data

Verify

POST /api/verify

Validates a proposed payment payload against facilitator requirements

Request body example:

{
  "paymentPayload": { "...": "..." },
  "paymentRequirements": { "...": "..." }
}

Settle

POST /api/settle

Settles a previously verified transaction

Request body example:

{
  "paymentPayload": { "...": "..." },
  "paymentRequirements": { "...": "..." }
}

Security

Store SOLANA_PRIVATE_KEY securely (Vercel/hosted secrets)
Set strict ALLOWED_ORIGINS for CORS
Enforce HTTPS in production
Add observability and rate limiting as needed