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Service Overview

SoloPay is a blockchain-based payment gateway. It provides a REST API and SDK to help merchants easily integrate ERC-20 token payments into their services.

About SoloPay

SoloPay's core feature is Gasless Payment. Users simply sign once in a wallet like MetaMask to complete a payment. Gas fees (network transaction fees) are covered by the SoloPay relayer server.

Key Benefits

FeatureDescription
Gas-free UXUsers complete payments with just a signature — no ETH/MATIC required
Fast IntegrationIntegrate via REST API or SDK within hours
orderId DeduplicationIdempotency guaranteed based on order ID
Real-time AlertsReceive payment status changes instantly via Webhook
Multi-token SupportMerchants can specify any ERC-20 token as the payment method
Built-in RefundsHandle on-chain refunds via API

Supported Networks and Assets

Supported Chains

ChainNetwork IDType
Polygon137Mainnet
Polygon Amoy80002Testnet

Service Endpoints

SoloPay provides separate development and production environments. Both environments support Testnet (Amoy) and Mainnet (Polygon).

Development — Updated without prior notice

ServiceURL
Payment APIhttps://gateway.dev.solonetwork.io
Integration Guidehttps://guide.dev.solonetwork.io
Payment Widgethttps://widget.dev.solonetwork.io
Sample Merchanthttps://sample-merchant.dev.solonetwork.io

Production — Updated with prior notice of changes

ServiceURL
Payment APIhttps://gateway.solonetwork.io
Integration Guidehttps://guide.solonetwork.io
Payment Widgethttps://widget.solonetwork.io
Sample Merchanthttps://sample-merchant.solonetwork.io

Production Environment

The production environment is not yet publicly available. Please use the development endpoints for integration and testing.

Supported Tokens

Merchants can specify which ERC-20 tokens to accept as payment. Tokens must be registered on SoloPay's platform whitelist.

Permit (EIP-2612) Supported Tokens

Tokens that support EIP-2612 such as USDC enable 100% gasless payments from the very first transaction — no Approve transaction required. Check the contract spec of the token you intend to integrate.

Prerequisites

The following steps are required to use SoloPay.

1. Merchant Registration

Contact the SoloPay operations team to register as a merchant. The following information is required:

  • Your service (e.g., store) domain
  • The chain you will use (e.g., Polygon Amoy 80002)
  • Recipient wallet address (the ERC-20 token wallet to receive payments)
  • The token address to use for payments

2. API Key Issuance

After merchant registration, you will receive two keys from the operations team.

Key TypePrefixPurposeUsage
API Keysk_...Admin/management operations (setup)Never in client code
Public Keypk_...Payment creation, status queriesClient-side (widget)

API Key Security

Never include API Keys starting with sk_ in frontend code. The API Key is for admin/management setup only and is not required for client-side widget integration.

3. Activate Payment Methods (Tokens)

After merchant registration, activate the tokens you want to use for payment. This is a one-time admin setup step performed outside the client-side integration.

Admin Setup

Contact the SoloPay operations team or use the dashboard to activate payment methods. If using the API directly, the POST /merchant/payment-methods endpoint requires the API Key (sk_...).

Next Steps

Non-custodial Web3 payment infrastructure for ERC-20 checkout, sponsored gas, and wallet-to-wallet settlement.